U.S. patent application number 17/016953 was filed with the patent office on 2021-07-01 for implantable therapeutic device.
The applicant listed for this patent is ForSight Vision4, Inc.. Invention is credited to Yair Alster, Randolph E. Campbell, Eugene de Juan, JR., Kathleen Cogan Farinas, K. Angela Macfarlane, Cary J. Reich.
Application Number | 20210196510 17/016953 |
Document ID | / |
Family ID | 1000005459312 |
Filed Date | 2021-07-01 |
United States Patent
Application |
20210196510 |
Kind Code |
A1 |
de Juan, JR.; Eugene ; et
al. |
July 1, 2021 |
IMPLANTABLE THERAPEUTIC DEVICE
Abstract
A therapeutic device to release a therapeutic agent comprises a
porous structure coupled to a container comprising a reservoir. The
reservoir comprises a volume sized to release therapeutic amounts
of the therapeutic agent for an extended time when coupled to the
porous structure and implanted in the patient. The porous structure
may comprise a first side coupled to the reservoir and a second
side to couple to the patient to release the therapeutic agent. The
length of the channels extending from the fist side to the second
side may comprise an effective length greater than a distance
across the porous structure from the first side to the second side.
The therapeutic device may comprise a penetrable barrier to inject
therapeutic agent into the device when implanted in the
patient.
Inventors: |
de Juan, JR.; Eugene; (South
San Francisco, CA) ; Alster; Yair; (South San
Francisco, CA) ; Farinas; Kathleen Cogan; (South San
Francisco, CA) ; Macfarlane; K. Angela; (South San
Francisco, CA) ; Reich; Cary J.; (South San
Francisco, CA) ; Campbell; Randolph E.; (South San
Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ForSight Vision4, Inc. |
South San Francisco |
CA |
US |
|
|
Family ID: |
1000005459312 |
Appl. No.: |
17/016953 |
Filed: |
September 10, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14753574 |
Jun 29, 2015 |
10813788 |
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17016953 |
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14147390 |
Jan 3, 2014 |
9066779 |
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14753574 |
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13204638 |
Aug 5, 2011 |
8623395 |
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14147390 |
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12696678 |
Jan 29, 2010 |
8399006 |
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13204638 |
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61407361 |
Oct 27, 2010 |
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61406934 |
Oct 26, 2010 |
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61371154 |
Aug 5, 2010 |
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61371136 |
Aug 5, 2010 |
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61371169 |
Aug 5, 2010 |
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61299282 |
Jan 28, 2010 |
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61284832 |
Dec 24, 2009 |
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61261717 |
Nov 16, 2009 |
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61174887 |
May 1, 2009 |
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61148375 |
Jan 29, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 9/0017 20130101;
C07K 16/22 20130101; A61M 37/00 20130101; A61K 9/0051 20130101;
A61K 45/06 20130101; A61K 38/179 20130101; A61K 39/395 20130101;
C07K 2317/94 20130101 |
International
Class: |
A61F 9/00 20060101
A61F009/00; A61K 9/00 20060101 A61K009/00; A61K 39/395 20060101
A61K039/395; A61K 45/06 20060101 A61K045/06; C07K 16/22 20060101
C07K016/22; A61K 38/17 20060101 A61K038/17 |
Claims
1. An ophthalmic drug delivery system comprising: an extended
release device configured to be implanted in an eye, the device
comprising: a reservoir formed of a non-permeable material and
defining a hollow reservoir volume; and a porous structure coupled
to the reservoir, the porous structure having a release rate tuned
to release a predetermined rate profile of a drug formulation from
the reservoir and into the eye to treat the eye for an extended
period of time; and a drug formulation configured to be contained
in and delivered by the extended release device, wherein the drug
formulation comprises: ranibizumab having a concentration in a
solution volume and a given half-life upon bolus injection of the
solution volume into the eye, wherein the extended release device
is tuned to the drug formulation to achieve an effective half-life
in the eye when the drug formulation is delivered by the
implantable extended release device that is longer than the given
half-life in the eye when the drug formulation is delivered by
bolus injection.
2. The system of claim 1, wherein the given half-life is within a
range from about 1 hour to about 9 days.
3. The system of claim 1, wherein the effective half-life is within
a range from about 18 days to about 250 days.
4. (canceled)
5. The system of claim 1, wherein the reservoir is refillable.
6. The system of claim 1, wherein the reservoir is flushable.
7. The system of claim 1, wherein the target body volume is the
vitreous of the eye.
8. The system of claim 1, wherein the effective half-life in the
target body volume maintains a concentration of the drug in the
target body volume that is above a therapeutic target concentration
for a longer period of time than the given half-life maintains the
concentration of the drug in the target body volume that is above
the therapeutic target concentration.
9. The system of claim 1, wherein the porous structure is coupled
to a distal end of the reservoir near an outlet of the
reservoir.
10. The system of claim 1, wherein the eye has neovascular (wet)
age-related macular degeneration.
11. The system of claim 1, wherein the porous structure has a
porosity P between about 3% to about 70% corresponding to the
percentage of void spaces extending within the rigid porous
structure.
12. The system of claim 1, wherein the reservoir is formed of a
rigid material and the reservoir volume is within a range from
about 10 uL to about 50 uL.
13. The system of claim 1, wherein the reservoir is formed of a
material configured to enlarge between a first narrow profile
configuration and a second expanded profile configuration.
14. The system of claim 13, wherein the reservoir volume is within
a range from about 10 uL to about 100 uL.
15. A method of treating an eye using the system of claim 1, the
method comprising: implanting the device into the eye; and
injecting into the reservoir the drug formulation comprising an
amount of ranibizumab.
16. The method of claim 15, wherein the amount of ranibizumab is
within a range from about 0.1 mg to about 30 mg.
17. The method of claim 15, wherein the drug formulation has a
concentration of ranibizumab within a range from about 10 mg/ML to
about 600 mg/ML.
18. A method of extending the half-life of ranzibizumab when
injected into the eye using the device of claim 1, the method
comprising: injecting an amount of the drug formulation of claim 1
into the reservoir of the device when implanted in the eye.
19. The method of claim 18, wherein the given half-life is within a
range from about 1 hour to about 9 days.
20. The method of claim 18, wherein the effective half-life is
within a range from about 18 days to about 250 days.
21. The method of claim 18, further comprising implanting the
device in the eye.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This Application is a continuation of co-pending U.S. patent
application Ser. No. 14/753,574 entitled, "Implantable Therapeutic
Device," filed Jun. 29, 2015, which is a continuation of U.S.
patent application Ser. No. 14/147,390 entitled "Implantable
Therapeutic Device," filed Jan. 3, 2014, now U.S. Pat. No.
9,066,779, which is a continuation of U.S. patent application Ser.
No. 13/204,638 entitled, "Implantable Therapeutic Device," filed 5
Aug. 2011, now U.S. Pat. No. 8,623,395, which claims priority to
U.S. Provisional Ser. Nos. 61/371,169, filed 5 Aug. 2010, entitled
"Implantable Therapeutic Device"; 61/406,934, filed on 26 Oct.
2010, entitled "Implantable Therapeutic Device"; 61/407,361, filed
on 27 Oct. 2010, entitled "Implantable Therapeutic Device";
61/371,136, filed 5 Aug. 2010, entitled "Expandable and Collapsible
Therapeutic Delivery Apparatus and Methods"; and 61/371,154,
entitled "Injector Apparatus and Method for Drug Delivery," filed
Aug. 5, 2010, the full disclosures of which are incorporated herein
by reference.
[0002] U.S. patent application Ser. No. 13/204,638 is also a
continuation-in-part patent application claiming priority to U.S.
patent application Ser. No. 12/696,678 filed 29 Jan. 2010, entitled
"Posterior Segment Drug Delivery" now U.S. Pat. No. 8,399,006,
which claims the benefit of priority to U.S. Provisional Patent
Application Nos. 61/299,282, filed 28 Jan. 2010, entitled
"Posterior Segment Drug Delivery;" 61/284,832, filed 24 Dec. 2009,
entitled "Posterior Segment Drug Delivery;" 61/261,717, filed 16
Nov. 2009, entitled "Posterior Segment Drug Delivery;" 61/174,887,
filed 1 May 2009, entitled "Posterior Segment Drug Delivery;"
61/261,717 entitled "Posterior Segment Drug Delivery," filed Nov.
16, 2009; and 61/148,375, filed 29 Jan. 2009, entitled "Posterior
Segment Drug Delivery;" the full disclosures of which are
incorporated herein by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH AND DEVELOPMENT
[0003] NOT APPLICABLE
BACKGROUND OF THE INVENTION
[0004] The present invention relates to delivery of therapeutic
agents to the posterior segment of the eye. Although specific
reference is made to the delivery of macromolecules comprising
antibodies or antibody fragments to the posterior segment of the
eye, embodiments of the present invention can be used to deliver
many therapeutic agents to many tissues of the body. For example,
embodiments of the present invention can be used to deliver
therapeutic agent to one or more of the following tissues:
intravascular, intra-articular, intrathecal, pericardial,
intraluminal and gut.
[0005] The eye is critical for vision. The eye has a cornea and a
lens that form an image on the retina. The image formed on the
retina is detected by rods and cones on the retina. The light
detected by the rods and cones of the retina is transmitted to the
occipital cortex brain via the optic nerve, such that the
individual can see the image formed on the retina. Visual acuity is
related to the density of rods and cones on the retina. The retina
comprises a macula that has a high density of cones, such that the
user can perceive color images with high visual acuity.
[0006] Unfortunately, diseases can affect vision. In some instances
the disease affecting vision can cause damage to the retina, even
blindness in at least some instances. One example of a disease that
can affect vision is age-related macular degeneration (hereinafter
AMD). Although therapeutic drugs are known that can be provided to
minimize degradation of the retina, in at least some instances the
delivery of these drugs can be less than ideal.
[0007] In some instances a drug is injected into the eye through
the sclera. One promising class of drugs for the treatment of AMD
is known as vascular endothelial growth factor VEGF inhibitors.
Unfortunately, in at least some instances injection of drugs can be
painful for the patient, involve at least some risk of infection
and hemorrhage and retinal detachment, and can be time consuming
for the physician and patient. Consequently, in at least some
instances the drug may be delivered less often than would be ideal,
such that at least some patients may receive less drug than would
be ideal in at least some instances.
[0008] Work in relation to embodiments of the present invention
also suggests that an injection of the drug with a needle results
in a bolus delivery of the drug, which may be less than ideal in at
least some instances. For example, with a bolus injection of drug,
the concentration of drug in the vitreous humor of the patient may
peak at several times the required therapeutic amount, and then
decrease to below the therapeutic amount before the next
injection.
[0009] Although some implant devices have been proposed, many of
the known devices are deficient in at least some respects in at
least some instances. At least some of the known implanted devices
do not provide sustained release of a therapeutic drug for an
extended period. For example, at least some of the known implanted
devices may rely on polymer membranes or polymer matrices to
control the rate of drug release, and many of the known membranes
and matrices may be incompatible with at least some therapeutic
agents such as ionic drugs and large molecular weight protein drugs
in at least some instances. At least some of the known
semi-permeable polymer membranes may have permeability that is less
than ideal for the extended release of large molecular weight
proteins such as antibodies or antibody fragments. Also, work in
relation to embodiments of the present invention also suggests that
at least some of the known semi-permeable membranes can have a
permeability of large molecules that may vary over time and at
least some of the known semi-permeable membranes can be somewhat
fragile, such that drug release for extended periods can be less
than ideal in at least some instances. Although capillary tubes
have been suggested for drug release, work in relation to
embodiments of the present invention suggests that flow through
capillary tubes can be less than ideal in at least some instances,
for example possibly due to bubble formation and partial
clogging.
[0010] At least some of the known implantable devices can result in
patient side effects in at least some instances when a sufficient
amount of drug is delivered to treat a condition of the eye. For
example, at least some of the commercially available small molecule
drug delivery devices may result in patient side effects such as
cataracts, elevated intraocular pressure, dizziness or blurred
vision in at least some instances. Although corticosteroids and
analogues thereof may be delivered with an implanted device to
treat inflammation, the drug delivery profile can be less than
ideal such that the patient may develop a cataract in at least some
instances.
[0011] Although at least some of the proposed implanted devices may
permit an injection into the device, one potential problem is that
an injection into an implanted device can cause at least some risk
of infection for the patient in at least some instances. Also, in
at least some instances the drug release rate of an implanted
device can change over time, such that the release rate of the drug
can be less than ideal after injection in at least some instance.
At least some of the proposed implanted devices may not be
implanted so as to minimize the risk of infection to the patient.
For example, at least some of the proposed devices that rely on
pores and capillaries may allow microbes such as bacteria to pass
through the capillary and/or pore, such that infection may be
spread in at least some instances. Also, work in relation to
embodiments of the present invention suggests that at least some of
the proposed implanted devices do not provide adequate protection
from the patient's immune system, such as from macrophages and
antibodies, thereby limiting the therapeutic effect in at least
some instances.
[0012] At least some of the prior injection devices may not be well
suited to inject an intended amount of a therapeutic agent into a
therapeutic device implanted in the eye in at least some instances.
For example, in at least some instances, coupling of the injector
to the therapeutic device implanted in the eye may be less than
ideal. Also, the therapeutic device may provide resistance to flow
such that injection can be difficult and may take more time than
would be ideal or the flow into the therapeutic device can be
somewhat irregular in at least some instances. The injector may
decouple from the therapeutic device such that the amount of
therapeutic agent delivered can be less than ideal in at least some
instances. In at least some instances, the injected therapeutic
agent may mix with a solution previously inside the therapeutic
device such that the amount of therapeutic agent that remains in
the device when the injection is complete can be more less than
ideal in at least some instances.
[0013] In light of the above, it would be desirable to provide
improved therapeutic devices and methods that overcome at least
some of the above deficiencies of the known therapies, for example
with improved drug release that can be maintained when implanted
over an extended time.
SUMMARY OF THE INVENTION
[0014] Embodiments of the present invention provide methods and
apparatus of injecting a formulation therapeutic agent into the
body, for example injection of the therapeutic agent into an
implanted therapeutic device such that the therapeutic agent is
delivered from the therapeutic device in therapeutic amounts for an
extended time that can be at least about 1 month. The injector
apparatus can accurately inject intended amounts of the therapeutic
agent into the therapeutic device, such that the amount of
therapeutic agent inside the chamber reservoir of the device and
the amount released into the eye correspond to substantially
targeted amounts. The injector apparatus may comprise a coupling
indicator to indicate when the injector apparatus is coupled to the
therapeutic device and an injector apparatus extends a sufficient
depth into the device for one or more of injection of the
therapeutic agent or exchange of the therapeutic agent with
material within the therapeutic device. The reservoir chamber of
the therapeutic device can be implanted in the eye such that the
reservoir chamber is located under the sclera, between the
conjunctiva and the sclera, or under the sclera in the vitreous
humor, or combinations thereof.
[0015] In many embodiments, the therapeutic device is configured to
provide continuous release of therapeutic quantities of at least
one therapeutic agent for an extended time of at least 3 months,
for example 6 months, such that the frequency of injections into
the therapeutic device and risk of infection can be substantially
decreased. In additional embodiments, the therapeutic device is
configured to provide continuous release of therapeutic quantities
of at least one therapeutic agent for an extended time of at least
12 months, or at least 2 years or at least 3 years.
[0016] The therapeutic device can be configured in many ways to
release the therapeutic agent for the extended time and may
comprise at least one of an opening, an elongate structure, a
porous structure, or a porous surface sized to release the
therapeutic agent for the extended time. For example, the
therapeutic device may comprise the porous structure to release the
therapeutic agent through the porous structure for the extended
period. The porous structure may comprise a sintered material
having many channels, for example interconnecting channels,
extending around many particles adhered to each other. The porous
structure may comprise a first side comprising a first plurality of
openings coupled to the reservoir and a second side comprising a
second plurality of openings to couple to the vitreous humor. The
interconnecting channels may extend between each of the first
plurality of openings of the first side and each of the second
plurality of openings of the second side so as to maintain release
of the therapeutic agent through the porous structure, for example
when at least some the openings are blocked. The porous structure
can be rigid and maintain release of the therapeutic agent through
the interconnecting channels when tissue or cells cover at least a
portion of the openings, for example when the porous structure is
implanted for an extended time and the drug reservoir refilled.
[0017] The therapeutic device may comprise a retention structure
configured to couple to the sclera to position the container for
delivery of the therapeutic agent into the vitreous humor of the
eye, such that the conjunctiva may extend over the retention
structure when the device is implanted so as to inhibit the risk of
infection to the patient and allow access to the device with
decreased risk of infection. For example, the retention structure
may comprise a flange extending outward for placement between the
conjunctiva and sclera and a narrow portion to fit within the
incision through the sclera. The narrow portion to fit the incision
may comprise an elongate cross sectional profile sized to fit the
incision. The elongate cross-sectional profile sized to fit the
incision can improve the fit of the implanted device to the scleral
incision, and may seal the implant against the sclera along the
incision. The elongate cross sectional profile of the narrow
portion can be sized in many ways to fit the incision. For example,
the elongate cross section may comprises a first dimension longer
than a second dimension and may comprise one or more of many shapes
such as dilated slit, dilated slot, lentoid, oval, ovoid, or
elliptical. The dilated slit shape and dilated slot shape may
correspond to the shape sclera tissue assumes when cut and dilated.
The lentoid shape may correspond to a biconvex lens shape. The
elongate cross-section of the narrow portion may comprise a first
curve along an first axis and a second curve along a second axis
different than the first curve.
[0018] In many embodiments, the reservoir of the therapeutic device
is flushable and/or refillable. This provides the added benefit
that the physician may remove the therapeutic agent from the
patient by flushing the agent from the reservoir of the therapeutic
device rather than waiting for the therapeutic agent to be
eliminated from the patient. This removal can be advantageous in
cases where the patient has an adverse drug reaction or benefit
from a pause in therapy sometimes referred to as a drug holiday.
The volume of the reservoir and release rate of the porous
structure can be tuned to receive a volume of a commercially
available formulation, such that the therapeutic agent can be
released for an extended time. For example, the volume of
commercially available therapeutic agent may correspond to a bolus
injection having a treatment duration, for example one month, and
the reservoir volume and release rate tuned to receive the
formulation volume can extend the treatment duration of the
injected volume by a factor of at least about two, for example from
one month to two or more months.
[0019] In a first aspect, embodiments provide a method of treating
an eye having a vitreous humor. At least about 3.5 mg of
ranibizumab is injected into a therapeutic device implanted in the
eye, and the amount can be within a range from about 3.5 to about
5.5 mg, for example about 4.5 mg. The therapeutic device has a
chamber volume sized to store no more than about 1.5 mg of
ranibizumab, for example no more than about 2.5 mg, such that at
least about 2 mg of ranibizumab is released from the therapeutic
device to the vitreous humor of the eye as a bolus injection.
[0020] In many embodiments, at least about 4 mg of ranibizumab is
injected into the therapeutic device implanted in the eye, such
that at least about 2 mg of ranibizumab is released from the
therapeutic device to the vitreous humor of the eye as a second
bolus injection.
[0021] In another aspect, embodiments provide a method of treating
an eye having a vitreous humor. A first amount of a therapeutic
agent is injected into a therapeutic device implanted in the eye. A
second amount of the therapeutic agent is injected into the
therapeutic device implanted in the eye. The second amount can be
less than the first amount based on a portion of the amount of
therapeutic agent contained in the therapeutic device when the
second amount is injected.
[0022] In many embodiments, the second amount is less than the
first amount based on a mixing ratio of the second amount with the
portion.
[0023] In many embodiments, the second amount is injected at least
about one month after the first amount is injected.
[0024] In another aspect, embodiments provide method of treating an
eye having a vitreous humor. A first amount of a therapeutic agent
is injected into a therapeutic device implanted in the eye. The
first amount corresponds to a first injection volume greater than a
chamber volume of the therapeutic device, such that a first portion
of the first amount is passed through the chamber into the vitreous
humor as a first bolus injection and a second contained portion is
contained in the chamber and released for an extended time. A
second amount of the therapeutic agent is injected into the
therapeutic device implanted in the eye, and the second amount
corresponds to a second injection volume greater than the chamber
volume of the therapeutic device, such that a first portion of the
second amount is passed through the chamber into the vitreous humor
as a second bolus injection and a second contained portion is
contained in the chamber and released for an extended time. The
second amount can be less than the first amount such that the
second bolus injection has no more therapeutic agent than the first
bolus injection.
[0025] In another aspect, embodiments provide a method of treating
an eye having a vitreous humor. An amount of therapeutic agent is
injected into a reservoir of a therapeutic device. The reservoir
has a substantially fixed volume coupled to a porous structure. The
amount may be greater than the substantially fixed volume, such
that a first portion of the amount is released into the vitreous
humor of the eye as a bolus injection and a second portion of the
amount is retained in the reservoir. The second portion may be
released from the porous structure at amounts lower than amounts of
the first portion, such that the bolus injection corresponds to a
maximum concentration of the therapeutic agent in the eye.
[0026] In many embodiments, the maximum concentration comprises no
more than a peak concentration of corresponding to an amount of the
bolus injection.
[0027] In another aspect, embodiments provide a method of treating
an eye having a vitreous humor and an established safe bolus amount
of a therapeutic agent. A first amount of a therapeutic agent is
injected into a therapeutic device implanted in the eye. A second
amount of the therapeutic agent is injected into the therapeutic
device implanted in the eye. A portion of the first amount of
therapeutic agent is contained in the therapeutic device when the
second amount is injected such that a second bolus is released from
the therapeutic device to the vitreous humor, the second bolus
comprising a second amount of the therapeutic agent greater than
the established safe bolus amount.
[0028] In many embodiments, the second amount comprises an
incremental increase in exposure to the therapeutic agent.
[0029] In many embodiments, further comprising injecting additional
bolus amounts above the second amount to establish a second safe
bolus amount.
[0030] In many embodiments, further comprising removing the
therapeutic agent from the therapeutic device based on a negative
response to the second amount of the therapeutic agent, wherein the
therapeutic agent is exchanged with a solution substantially
lacking the therapeutic agent.
[0031] In another aspect, embodiments provide an apparatus to treat
an eye an eye with a therapeutic agent having an established safe
amount. An injector has a volume of liquid comprising an amount of
therapeutic agent. A therapeutic device has a chamber volume sized
smaller than the injector volume to release a bolus of the
therapeutic agent.
[0032] In another aspect, embodiments provide a sustained drug
delivery formulation comprising a therapeutic agent wherein the
therapeutic agent is contained in a reservoir of the device as
described above, and the therapeutic agent has a half-life within
the reservoir when implanted. The half life within the reservoir is
substantially greater than a corresponding half-life of the at
least one of the therapeutic agent when injected directly into the
vitreous of an eye.
[0033] In many embodiments, the device can be configured by
selection of the reservoir volume and a porous structure with an
appropriate rate release index to achieve the desired effective
half-life.
[0034] In many embodiments, the rate release index of the porous
structure is from about 0.001 to about 5, for example from about
0.002 to about 5, and can be from about 0.01 to about 5.
[0035] In many embodiments, the first therapeutic agent is a
VEGF-inhibitor and the second therapeutic agent is an inflammatory
response inhibitor.
[0036] In another aspect, embodiments provide sustained drug
delivery formulation to treat a patient of a population. The
formulation comprises a therapeutic agent, and the therapeutic
agent has a half-life within the eye corresponding to a half life
the therapeutic agent injected into a device implanted in the
eye.
[0037] In another aspect, embodiments provide a method of treating
an eye. An amount therapeutic agent is injected into a therapeutic
device, and the amount within a range from about 0.01 mg to about
50 mg, and the range can be from about 0.1 mg to about 30 mg.
[0038] In another aspect, embodiments provide an apparatus to treat
an eye. The apparatus comprises an amount of formulation
corresponding to an amount of therapeutic agent, in which the
amount within a range from about 0.01 mg to about 50 mg, and the
range can be from about 0.1 to about 30 mg. A therapeutic device
has a reservoir chamber and porous structure tuned to receive the
amount of formulation corresponding to the amount of therapeutic
agent.
[0039] In many embodiments, the amount is within a range is from
about 0.1 mg to about 30 mg.
[0040] In another aspect, embodiments provide an apparatus to treat
an eye with a therapeutic agent. The apparatus comprises an
injector having a volume of fluid comprising an amount of
therapeutic agent. A therapeutic device comprises a reservoir
chamber, and the reservoir chamber has a volume sized to receive
the amount of therapeutic agent. The amount of therapeutic agent is
placed in the reservoir chamber.
[0041] In many embodiments, the fluid comprises a concentration of
ranibizumab within a range from about 40 mg/mL to about 200 mg/mL,
for example within a range from about 40 mg/ml to about 100
mg/mL.
[0042] In many embodiments, the injector is configured to place the
amount with no substantial bolus.
[0043] In many embodiments, the injector is configured to place the
amount with an exchange efficiency of at least about 80%.
[0044] In many embodiments, the injector comprises an injection
lumen to inject the therapeutic and a vent to receive fluid of the
chamber, the therapeutic device comprises a reservoir chamber to
release the therapeutic agent. The vent may comprise a resistance
to flow substantially lower than a resistance to flow of the porous
structure of the therapeutic device so as to inhibit a bolus of the
therapeutic agent through the porous structure.
[0045] In another aspect, embodiments provide an apparatus to treat
an eye an eye with a therapeutic agent. A volume of a fluid
comprising an amount of therapeutic agent is injected into a
therapeutic device comprising a reservoir chamber. The reservoir
chamber has a volume sized to receive the amount of therapeutic
agent, and the amount of therapeutic agent is placed in the
reservoir chamber.
[0046] In many embodiments, the injector is configured to place the
amount with an exchange efficiency of at least about 80%.
[0047] In many embodiments, the amount is placed in the reservoir
chamber with no substantial bolus of the fluid comprising the
therapeutic agent through the porous structure.
[0048] In another aspect, embodiments provide an expandable and
collapsible therapeutic device having a substantially fixed volume.
The therapeutic device may comprise a first narrow profile
configuration for placement, and a second expanded wide profile
configuration to deliver the drug with the reservoir when
positioned in the eye. The expanded device having one or more
support structures can be collapsed, for example compressed or
extended to decrease cross sectional size, such that the device can
fit through the incision. For example, the therapeutic device may
comprise a flexible barrier material coupled to a support, such
that the barrier material and support can be expanded from a first
narrow profile configuration to the second expanded profile
configuration, and subsequently collapsed to the first narrow
profile configuration for removal. The support can provide a
substantially constant reservoir volume in the expanded
configuration, such that the device can be tuned with the porous
structure and expandable reservoir to receive the volume of
therapeutic agent formulation and so as to release therapeutic
amounts for the extended time. The therapeutic device may comprise
a porous barrier extending around the container with channels sized
to pass the therapeutic agent from the container therethrough and
to inhibit migration of at least one of a bacterial cell out of the
container or a macrophage or other immune cell into the container.
To remove the therapeutic device having the flexible barrier
coupled to the support, the support can be collapsed at least
partially for removal, for example with elongation along an axis of
the therapeutic device such that the cross sectional size of the
support is decreased for removal through the incision. In many
embodiments, a proximal end of the therapeutic device is coupled to
a removal apparatus, and an elongate structure couples to a distal
portion of the therapeutic device and is extended along such that
the distal portion is urged distally and the cross sectional size
of the support decreased for removal through the incision. The
elongate structure may comprise one or more of a needle, a shaft, a
mandrel or a wire, and the distal portion may comprise a stop
coupled to the support such as the porous structure or a portion of
the support, such that the support is extended along the axis for
removal when the elongate structure is advanced distally.
[0049] In many embodiments, a removal apparatus comprises the
elongate structure and jaws to couple to the retention structure
and wherein the elongate structure comprises one or more of a
needle, a shaft, a mandrel or a wire.
[0050] In many embodiments, the porous structure comprises a rigid
porous structure affixed to a distal end of the support to release
the therapeutic agent into a vitreous humor of the eye for an
extended time. The flexible support and flexible barrier may
comprise flexibility sufficient to increase the length increases
from the second length to the first length when the elongate
structure contacts the rigid porous structure.
[0051] In many embodiments, the support comprises a plurality of
flexible struts that extend axially from the retention structure to
an annular flange sized to support the porous structure on the
distal end of device, and wherein the flexible struts comprise are
space apart when the device comprises the second expanded profile
configuration to define the chamber having the substantially
constant volume.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 shows an eye suitable for incorporation of the
therapeutic device, in accordance with embodiments of the present
invention;
[0053] FIG. 1A-1 shows a therapeutic device implanted at least
partially within the sclera of the eye as in FIG. 1;
[0054] FIG. 1A-1-1 and 1A-1-2 show a therapeutic device implanted
under the conjunctiva and extending through the sclera to release a
therapeutic agent into vitreous humor of the eye so as to treat the
retina of the, in accordance with embodiments of the present
invention;
[0055] FIG. 1A-2 shows structures of a therapeutic device
configured for placement in an eye as in FIGS. 1A-1 and 1A-1-1,
according to embodiments of the present invention;
[0056] FIG. 1A-2-1 shows a therapeutic device loaded into an
insertion cannula, in which the device comprises an elongate narrow
shape for insertion into the sclera, and in which the device is
configured to expand to a second elongate wide shape for retention
at least partially in the sclera;
[0057] FIG. 1A-2-2 shows a therapeutic device comprising a
reservoir suitable for loading in a cannula;
[0058] FIG. 1B shows a therapeutic device configured for placement
in an eye as in FIG. 1A-1 and 1A-1-1, in accordance with
embodiments of the present invention;
[0059] FIG. 1C shows a therapeutic device configured for placement
in an eye as in FIG. 1A-1 and 1A-1-1, in accordance with
embodiments of the present invention;
[0060] FIG. 1C-A shows at least one exit port, according to
embodiments of the present invention;
[0061] FIG. 1C-1 shows a method of removing a binding material,
according to embodiments of the present invention;
[0062] FIG. 1C-2 and inserting the therapeutic agent with a second
insert having the TA bound thereon;
[0063] FIG. 1C-3 shows syringe being filled with a commercially
available formulation of therapeutic agent for injection into the
therapeutic device, in accordance with embodiments;
[0064] FIG. 1D shows a therapeutic device configured for placement
in an eye as in FIG. 1A-1 and 1A-1-1, in which the device comprises
a plurality of chambers and channels connecting the chambers so as
to linearize the release of the therapeutic agent;
[0065] FIG. 1E shows a therapeutic device configured for placement
in an eye as in FIGS. 1A-1 and 1A-1-1, in which the device
comprises a needle stop located at the bottom of the therapeutic
device;
[0066] FIG. 1E-1 shows a therapeutic device configured for
placement in an eye as in FIGS. 1A-1 and 1A-1-1, in which the
device comprises a needle stop located at the bottom of the
therapeutic device and the shape of the device encourages the
movement of the therapeutic agent within the chamber of the
therapeutic device;
[0067] FIG. 1E-2 shows a therapeutic device configured for
placement in an eye as in FIGS. 1A-1 and 1A-1-1, in which the
device comprises a needle stop located in the middle of the
therapeutic device;
[0068] FIG. 1E-3 shows a therapeutic device configured for
placement in an eye as in FIGS. 1A-1 and 1A-1-1, in which the
device comprises a needle stop located in the middle of the
therapeutic device and the shape of the device encourages the
movement of the therapeutic agent within the chamber of the
therapeutic device;
[0069] FIG. 1E-3-1 shows a top view of the therapeutic device
configured for placement in an eye as in FIGS. 1E-3;
[0070] FIG. 2 shows an access port suitable for incorporation with
the therapeutic device, in accordance with embodiments of the
present invention;
[0071] FIG. 3A shows a collar suitable for incorporation with the
therapeutic device, in accordance with embodiments of the present
invention;
[0072] FIG. 3B shows biocompatible material impregnated with an
anti-bacterial agent on the therapeutic device to inhibit bacterial
growth along the device from the sclera to the vitreous humor;
[0073] FIG. 4A shows released fragments of antibodies, and FIG. 4B
shows antibody fragments reversibly bound to a substrate, in
accordance with embodiments of the present invention;
[0074] FIG. 5A shows a therapeutic device coupled to an injector to
insert therapeutic agent into the device;
[0075] FIG. 5A-1 shows a therapeutic device coupled to an injector
to simultaneously inject and remove material from the device;
[0076] FIG. 5B shows a therapeutic device comprising a micro loop
channel;
[0077] FIG. 5C-1 shows a therapeutic device comprising a tortuous
channel;
[0078] FIG. 5C-2 shows a therapeutic device comprising a coiled
channel;
[0079] FIG. 5D shows an expandable and contractible structure to
retain the therapeutic agent and an outer rigid casing to couple to
the sclera;
[0080] FIGS. 5E shows a membrane disposed over an exit port of a
therapeutic device;
[0081] FIG. 5F shows a therapeutic device comprising a tubular
membrane clamped onto the therapeutic device;
[0082] FIG. 6A-1 shows a therapeutic device comprising a container
having a penetrable barrier disposed on a first end, a porous
structure disposed on a second end to release therapeutic agent for
an extended period, and a retention structure comprising an
extension protruding outward from the container to couple to the
sclera and the conjunctiva;
[0083] FIG. 6A-2 shows a therapeutic device as in FIG. 6A
comprising a rounded distal end;
[0084] FIG. 6B shows a rigid porous structure configured for
sustained release with a device as in FIG. 6A;
[0085] FIG. 6B-1 shows interconnecting channels extending from a
first side to a second side of the porous structure as in FIG.
6B;
[0086] FIG. 6B-2 shows a plurality of paths of the therapeutic
agent along the interconnecting channels extending from a first
side to a second side of the porous structure as in FIGS. 6B and
6B1;
[0087] FIG. 6B-3 shows blockage of the openings with a covering and
the plurality of paths of the therapeutic agent along the
interconnecting channels extending from a first side to a second
side of the porous structure as in FIGS. 6B and 6B-1;
[0088] FIG. 6B-4 shows blockage of the openings with particles and
the plurality of paths of the therapeutic agent along the
interconnecting channels extending from a first side to a second
side of the porous structure as in FIGS. 6B and 6B-1;
[0089] FIG. 6B-5 shows an effective cross-sectional size and area
corresponding to the plurality of paths of the therapeutic agent
along the interconnecting channels extending from a first side to a
second side of the porous structure as in FIGS. 6B and 6B-1;
[0090] FIG. 6C shows a rigid porous structure as in FIG. 6B
incorporated into a scleral tack;
[0091] FIG. 6D, shows a rigid porous structure as in FIG. 6B
coupled with a reservoir for sustained release;
[0092] FIG. 6E shows a rigid porous structure as in FIG. 6B
comprising a hollow body or tube for sustained release;
[0093] FIG. 6F shows a rigid porous structure as in FIG. 6B
comprising a non-linear helical structure for sustained
release;
[0094] FIG. 6G shows porous nanostructures, in accordance with
embodiments;
[0095] FIG. 7 shows a therapeutic device coupled to an injector
that removes material from the device and injects therapeutic agent
into the device, according to embodiments;
[0096] FIG. 7A shows a therapeutic device comprising a porous
structure and a penetrable barrier as in FIG. 6E, with the
penetrable barrier coupled to an injector to inject and remove
material from the device, in accordance with embodiments;
[0097] FIG. 7A-1 shows a therapeutic device coupled to an injector
needle comprising a stop that positions the distal end of the
needle near the proximal end of the device to flush the reservoir
with ejection of liquid formulation through the porous frit
structure, in accordance with embodiments;
[0098] FIG. 7A-2 shows a therapeutic device comprising a penetrable
barrier coupled to an injector to inject and remove material from
the device such that the liquid in the reservoir is exchanged with
the injected formulation, in accordance with embodiments;
[0099] FIG. 7A-3 shows a deformable visual indicator;
[0100] FIG. 7A-4 shows the visual indicator coupled to soft tissue,
such as tissue of an eye, for example the conjunctiva positioned
over the penetrable barrier of the therapeutic device;
[0101] FIG. 7A-5 shows a therapeutic device 100 coupled to injector
701 with one or more of potentially insufficient force prior to
injection or potentially insufficient depth;
[0102] FIG. 7A-6 shows a therapeutic device 100 coupled to injector
701 with one or more of potentially insufficient force prior to
injection or potentially insufficient depth;
[0103] FIG. 7A-7A to FIG. 7A-9B show sliding coupling of a valve to
a plunger coupled to a piston to exchange a first intended volume
of liquid within the reservoir with a volume of formulation of
therapeutic agent and close the valve so as to inject a second
volume of liquid through the porous frit structure;
[0104] FIG. 7A-10A and FIG. 7A-10B show a first configuration of an
injector to maintain the rate of flow into device to within about
+/-50%, for example to within about +/-25%, such that the time to
inject the therapeutic agent into device 100 remains substantially
constant among devices and injections;
[0105] FIG. 7B-1 shows a side cross-sectional view of a therapeutic
device comprising a retention structure having a cross-section
sized to fit in an elongate incision, in accordance with
embodiments;
[0106] FIG. 7B-2 shows an isometric view of the therapeutic device
as in FIG. 7B-1;
[0107] FIG. 7B-3 shows a top view of the therapeutic device as in
FIG. 7B-1;
[0108] FIG. 7B-4 shows a side cross sectional view along the short
side of the retention structure of the therapeutic device as in
FIG. 7B-1;
[0109] FIG. 7B-5 shows a bottom view of the therapeutic device as
in FIG. 7B-1 implanted in the sclera;
[0110] FIG. 7B-5A shows a cutting tool comprising a blade having a
width corresponding to the perimeter of the barrier and the
perimeter of the narrow retention structure portion;
[0111] FIGS. 7B-6A and 7B-6B show distal cross-sectional view and a
proximal cross-sectional view, respectively, of a therapeutic
device comprising an elongate and non-circular cross-sectional
size, in accordance with embodiments;
[0112] FIG. 7B-6C shows an isometric view of the therapeutic device
having a retention structure with an elongate cross-sectional size,
in accordance with embodiments;
[0113] FIG. 7B-6D shows a distal end view of the therapeutic device
as in FIG. 7B-6C;
[0114] FIG. 7B-6E1 shows a side view of the short axis of the
narrow neck portion of the therapeutic device as in FIG. 7B-6C;
[0115] FIG. 7B-6E2 shows a side view of the long axis of the narrow
neck portion of the therapeutic device as in FIG. 7B-6C;
[0116] FIG. 7B-6F shows a proximal view of the therapeutic device
as in FIGS. 7B-6C;
[0117] FIG. 7B-6G to FIG. 7B-6I show exploded assembly drawings for
the therapeutic device as in FIGS. 7B-6C to 7B-6F;
[0118] FIG. 7C-1 shows an expandable therapeutic device comprising
an expandable barrier material and support in an expanded
configuration for extended release of the therapeutic agent, in
accordance with embodiments;
[0119] FIG. 7C-1A shows the distal end portion of the support 160S
as in FIG. 7C-1;
[0120] FIG. 7C-1B shows the support 160S disposed inside the
barrier 160, in accordance with embodiments;
[0121] FIG. 7C-1C shows the support 160S disposed along the inner
surface of the barrier 160, in accordance with embodiments;
[0122] FIG. 7C-1D shows an elongate structure of a removal
apparatus inserted into the expandable and collapsible
cross-section device to decrease the cross-sectional width of the
device;
[0123] FIG. 7C-1E shows the first elongate profile configuration of
support 160S comprising first length L1 and first width W1; and
[0124] FIG. 7C-1F shows the second wide profile configuration of
support 160S comprising second length L2 and second width W2;
[0125] FIG. 7C-2 shows the expandable therapeutic device as in FIG.
7C1 in a narrow profile configuration;
[0126] FIG. 7C-3 shows the expandable therapeutic device as in FIG.
7C1 in an expanded profile configuration;
[0127] FIGS. 7C-4A and 7C-4B show an expandable retention
structure, in accordance with embodiments;
[0128] FIG. 7D shows a therapeutic device comprising a porous
structure positioned in an eye to deliver a therapeutic agent to a
target location on the retina, in accordance with embodiments
[0129] FIG. 7E shows a therapeutic device comprising a porous
structure located on the device to deliver a therapeutic agent to
one or more of the ciliary body or the trabecular meshwork when
positioned in the eye, in accordance with embodiments;
[0130] FIG. 7F shows therapeutic device 100 comprising porous
structure 150 oriented to release the therapeutic agent away from
the lens and toward the retina, in accordance with embodiments;
[0131] FIG. 7G shows a kit comprising a placement instrument, a
container, and a therapeutic device within the container, in
accordance with embodiments;
[0132] FIG. 8 show reservoirs with exit ports of defined diameters
fabricated from 1 mL syringes with Luer-Lok.TM. tips and needles of
varying diameter, in accordance with embodiments;
[0133] FIG. 8-1 shows the needles attached to syringes as in FIG.
8;
[0134] FIG. 8-2 shows the reservoirs placed into vials;
[0135] FIG. 9 shows cumulative release through the needles of
varying diameter;
[0136] FIG. 10 shows release rate as a function of area;
[0137] FIG. 11 shows a reservoir with a porous membrane fabricated
by cutting off the Luer-Lok tip on a 1 mL syringe;
[0138] FIG. 11-1 shows the delivery rates from two replicates of a
reservoir as in FIG. 11;
[0139] FIG. 12 shows the cumulative release of fluorescein through
cut-off needles;
[0140] FIG. 13 shows the cumulative release of BSA protein through
a sintered porous titanium cylinder;
[0141] FIG. 13-1 shows the measured cumulative release of BSA of
FIG. 13 measured to 180 days;
[0142] FIG. 14 shows the cumulative release of BSA protein through
a masked sintered porous titanium cylinder at Condition 1, in
accordance with experimental embodiments;
[0143] FIG. 15 shows cumulative release of BSA protein through a
masked sintered porous titanium cylinder at Condition 2, in
accordance with experimental embodiments;
[0144] FIG. 16 shows cumulative release of BSA protein through a
masked sintered porous titanium cylinder at Condition 3, in
accordance with experimental embodiments;
[0145] FIG. 17 shows cumulative release of BSA through 0.1 media
grade sintered porous stainless steel cylinder;
[0146] FIG. 18A shows cumulative release of BSA through 0.2 media
grade sintered porous stainless steel cylinder;
[0147] FIG. 18B shows cumulative release of BSA through 0.2 media
grade sintered porous stainless steel cylinder for 180 days;
[0148] FIG. 19A compares calculated Lucentis.TM. pharmacokinetics
profiles to the pharmacokinetics profiles predicted for the device
in Example 8;
[0149] FIG. 19B shows determined concentrations of ranibizumab in
the vitreous humor for a first 50 uL Lucentis.TM. injection into a
25 uL reservoir of the device and a second 50 uL injection at 90
days, in accordance with embodiments;
[0150] FIG. 19C shows determined concentrations of ranibizumab in
the vitreous humor for a first 50 uL Lucentis.TM. injection into a
32 uL reservoir of the device and a second 50 uL injection at 90
days, in accordance with embodiments;
[0151] FIG. 19D shows determined concentrations of ranibizumab in
the vitreous humor for a first 50 uL Lucentis.TM. injection into a
50 uL reservoir of the device and a second 50 uL injection at 90
days, in accordance with embodiments;
[0152] FIG. 19E shows determined concentrations of ranibizumab in
the vitreous humor for a first 50 uL Lucentis.TM. injection into a
50 uL reservoir of the device and a second 50 uL injection at 130
days, in accordance with embodiments;
[0153] FIG. 19F shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 50 uL
device having a release rate index of 0.05, in accordance with
embodiments;
[0154] FIG. 19G shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 75 uL
device having a release rate index of 0.05, in accordance with
embodiments;
[0155] FIG. 19H shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 100 uL
device having a release rate index of 0.05, in accordance with
embodiments;
[0156] FIG. 19I shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 125 uL
device having a release rate index of 0.05, in accordance with
embodiments;
[0157] FIG. 19J shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 150 uL
device having a release rate index of 0.05, in accordance with
embodiments;
[0158] FIG. 19K shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 100 uL
device having a release rate index of 0.1, in accordance with
embodiments;
[0159] FIG. 19L shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.105, in accordance with embodiments;
[0160] FIG. 19M shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.095, in accordance with embodiments;
[0161] FIG. 19N shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.085, in accordance with embodiments;
[0162] FIG. 190 shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.075, in accordance with embodiments;
[0163] FIG. 19P shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.065, in accordance with embodiments;
[0164] FIG. 19Q shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL concentrated Lucentis.TM. (40 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about nine days, in accordance with embodiments;
[0165] FIG. 19R shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL concentrated Lucentis.TM. (40 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about five days, in accordance with embodiments;
[0166] FIG. 19S shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL standard Lucentis.TM. (10 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about nine days, in accordance with embodiments;
[0167] FIG. 19T shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL standard Lucentis.TM. (10 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about five days, in accordance with embodiments;
[0168] FIG. 20 shows a calculated time release profile of a
therapeutic agent suspension in a reservoir, in accordance with
embodiments.
[0169] FIG. 21 shows cumulative release for Avastin.TM. with
therapeutic devices comprising substantially similar porous frit
structures and a 16 uL reservoir and a 33 uL reservoir;
[0170] FIG. 22A shows cumulative release for Avastin.TM. with
porous frit structures having a thickness of 0.049'';
[0171] FIG. 22B-1 shows cumulative release for Avastin.TM. with
porous frit structures having a thickness of 0.029'';
[0172] FIG. 22B-2 shows rate of release for Avastin.TM. with porous
frit structures having a thickness of 0.029'' as in FIG. 22B-1;
[0173] FIG. 23A shows cumulative release for Avastin.TM. with a
reservoir volume of 20 uL;
[0174] FIG. 23A-1 shows cumulative release to about 90 days for
Avastin.TM. with a reservoir volume of 20 uL as in FIG. 23A;
[0175] FIG. 23B shows rate of release as in FIG. 23A;
[0176] FIG. 23B-1 shows rate of release as in FIG. 23A-1;
[0177] FIG. 24A shows cumulative release for Avastin.TM. with a 0.1
media grade porous frit structure;
[0178] FIG. 24A-1 shows cumulative release to about 90 days release
for Avastin.TM. with a 0.1 media grade porous frit structure as in
FIG. 24A;
[0179] FIG. 24B shows rates of release of the devices as in FIG.
24A;
[0180] FIG. 24B-1 shows rates of release of the devices as in FIG.
24A-1;
[0181] FIG. 25A shows cumulative release for fluorescein through a
0.2 media grade porous frit structure;
[0182] FIG. 25A-1 shows cumulative release to about 90 days for
fluorescein through a 0.2 media grade porous frit structure as in
FIG. 25A;
[0183] FIG. 25B shows rates of release of the devices as in FIG.
25A;
[0184] FIG. 25B-1 shows rates of release of the devices as in FIG.
25A-1;
[0185] FIG. 25C shows cumulative release to about thirty days for
Lucentis.TM. through a 0.2 media grade porous frit structure having
a diameter of 0.038 in and a length (thickness) of 0.029 in.;
[0186] FIG. 25D shows rates of release of the devices as in FIG.
25C;
[0187] FIG. 25E shows cumulative release to about thirty days for
Lucentis.TM. for 30 uL devices having a RRI's from about 0.015 to
about 0.090;
[0188] FIG. 25F shows rates of release of the devices as in FIG.
25E;
[0189] FIGS. 25E1 and 25F1 shows an update of Lucentis drug release
studies in FIGS. 25E and 25F, respectively, measured up to 6
months;
[0190] FIGS. 26A and 26B show scanning electron microscope images
from fractured edges of porous frit structures so as to show the
structure of the porous structure to release the therapeutic agent,
in accordance with embodiments;
[0191] FIGS. 27A and 27B show scanning electron microscope images
from surfaces of porous frit structures, in accordance with
embodiments;
[0192] FIG. 28 shows a pressure decay test and test apparatus for
use with a porous structure so as to identify porous frit
structures suitable for use with therapeutic devices in accordance
with embodiments described herein;
[0193] FIG. 29 shows a pressure flow test and test apparatus
suitable for use with a porous structure so as to identify porous
frit structures suitable for use with therapeutic devices in
accordance with embodiments described herein;
[0194] FIG. 30A-1 shows an example of an OCT macular cube OCT image
used to identify a region of interest (black arrow) and determine
the response to treatment;
[0195] FIGS. 30B-1, 30B-2 and 30B-3 show an example of a series of
OCT scan images at pre-injection, one day post-injection and one
week post-injection, respectively, of sections of the region of
interest;
[0196] FIGS. 31A and 31B shows experimental implantation of
therapeutic device into the pars plana region 25 of a rabbit eye
with visualization of the device sealing the elongate incision
under the flange and dark field visualization of the implanted
therapeutic device;
[0197] FIG. 32A shows the concentration profile of monthly bolus
injections of 2 mg of ranibizumab directly into the vitreous humor
as compared with an injection into the device 100 comprising 4.5 mg
ranibizumab such that 2.5 mg of ranibizumab are stored in the
device and 2 mg of ranibizumab are injected into the eye through
the porous structure 150;
[0198] FIG. 32B shows the concentration profile of monthly bolus
injections of 2 mg of ranibizumab directly into the vitreous humor
as compared with a plurality of injections into the device 100
comprising 4.5 mg ranibizumab such that 2.5 mg of ranibizumab are
stored in the device and 2 mg of ranibizumab are injected into the
eye through the porous structure 150;
[0199] FIG. 32C shows the plurality of ranibizumab injections of
4.5 mg and the monthly bolus injections of 2 mg as in FIG. 32B as
compared with monthly bolus injections of 0.5 mg of commercially
available and approved Lucentis.TM.;
[0200] FIGS. 32D and 32E show injections with amounts into the
device 100 and bolus injections similar to FIGS. 32A to 32C, in
which the injections are performed at 6 months;
[0201] FIGS. 33A and 33A1 show a side cross sectional view and a
top view, respectively, of therapeutic device 100 for placement
substantially between the conjunctiva and the sclera;
[0202] FIG. 33A2 shows the therapeutic device 100 implanted with
the reservoir between the conjunctiva and the sclera, such that
elongate structure 172 extends through the sclera to couple the
reservoir chamber to the vitreous humor;
[0203] FIG. 33B shows the porous structure 150 of therapeutic
device 100 located in channel 174 near the opening to the chamber
of the container 130;
[0204] FIG. 33C shows the porous structure 150 located within the
chamber of container 150 and coupled to the first opening of the
elongate structure 172 so as to provide the release rate
profile;
[0205] FIG. 33D shows a plurality of injection ports spaced apart
so as to inject and exchange the liquid of chamber of the container
130 and inject the therapeutic agent into the reservoir chamber of
the container 130;
[0206] FIG. 34 shows the elongate structure 172 coupled to the
container 130 away from the center of container 130 and near and
located near an end of the container;
[0207] FIG. 35 shows stability data for a formulation of Lucentis
that can be used to identify materials for porous frit structures,
in accordance with embodiments
[0208] FIG. 36A shows amounts of ranibizumab released at about 90
days for a 100 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0209] FIG. 36B shows amounts of ranibizumab released at about 180
days for a 100 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0210] FIG. 36C shows amounts of ranibizumab released at about 90
days for a 10 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0211] FIG. 36D shows amounts of ranibizumab released at about 180
days for a 10 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0212] FIG. 37 shows vitreous humor concentration profiles
corresponding to ranibizumab formulations of 40 mg/mL and 100 mg/mL
injected into the therapeutic device, in accordance with
embodiments;
[0213] FIG. 37A shows release of Ranibizumab formulations to 180
days from a therapeutic device comprising an RRI of 0.02 and a
volume of 25 uL corresponding to an effective half life of the
therapeutic agent in the device of 100 days;
[0214] FIG. 37B shows release of Ranibizumab to 180 days from a
therapeutic device comprising an RRI of 0.008 and a volume of 25 uL
corresponding to an effective half life of the therapeutic agent in
the device of 250 days, in accordance with embodiments; and
[0215] FIG. 37C shows release of ranibizumab from a population of
devices receiving injections of 40 mg/mL formulation and 100 mg/mL
formulation, in accordance with embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0216] Although specific reference is made to the delivery of
macromolecules comprising antibodies or antibody fragments to the
posterior segment of the eye, embodiments of the present invention
can be used to deliver many therapeutic agents to many tissues of
the body. For example, embodiments of the present invention can be
used to deliver therapeutic agent for an extended period to one or
more of the following tissues: intravascular, intra articular,
intrathecal, pericardial, intraluminal and gut.
[0217] Embodiments of the present invention provide sustained
release of a therapeutic agent to the posterior segment of the eye
or the anterior segment of the eye, or combinations thereof.
Therapeutic amounts of a therapeutic agent can be released into the
vitreous humor of the eye, such that the therapeutic agent can be
transported by at least one of diffusion or convection to the
retina or other ocular tissue, such as the choroid or ciliary body,
for therapeutic effect.
[0218] As used herein the release rate index encompasses (PA/FL)
where P comprises the porosity, A comprises an effective area, F
comprises a curve fit parameter corresponding to an effective
length and L comprises a length or thickness of the porous
structure. The units of the release rate index (RRI) comprise units
of mm unless indicated otherwise and can be determine by a person
of ordinary skill in the art in accordance with the teachings
described hereon.
[0219] As used herein, sustained release encompasses release of
therapeutic amounts of an active ingredient of a therapeutic agent
for an extended period of time. The sustained release may encompass
first order release of the active ingredient, zero order release of
the active ingredient, or other kinetics of release such as
intermediate to zero order and first order, or combinations
thereof.
[0220] As used herein a therapeutic agent referred to with a trade
name encompasses one or more of the formulation of the therapeutic
agent commercially available under the tradename, the active
ingredient of the commercially available formulation, the generic
name of the active ingredient, or the molecule comprising the
active ingredient.
[0221] As used herein, similar numerals indicate similar structures
and/or similar steps.
[0222] The therapeutic agent may be contained within a chamber of a
container, for example within a reservoir comprising the container
and chamber. The therapeutic agent may comprise a formulation such
as solution of therapeutic agent, a suspension of a therapeutic
agent or a dispersion of a therapeutic agent, for example. Examples
of therapeutic agents suitable for use in accordance with
embodiments of the therapeutic device are described herein, for
example with reference to Table 1A below and elsewhere.
[0223] The therapeutic agent may comprise a macromolecule, for
example an antibody or antibody fragment. The therapeutic
macromolecule may comprise a VEGF inhibitor, for example
commercially available Lucentis.TM.. The VEGF (Vascular Endothelial
Growth Factor) inhibitor can cause regression of the abnormal blood
vessels and improvement of vision when released into the vitreous
humor of the eye. Examples of VEGF inhibitors include Lucentis.TM.,
Avastin.TM., Macugen.TM., and VEGF Trap.
[0224] The therapeutic agent may comprise small molecules such as
of a corticosteroid and analogues thereof. For example, the
therapeutic corticosteroid may comprise one or more of
trimacinalone, trimacinalone acetonide, dexamethasone,
dexamethasone acetate, fluocinolone, fluocinolone acetate, or
analogues thereof. Alternatively or in combination, he small
molecules of therapeutic agent may comprise a tyrosine kinase
inhibitor comprising one or more of axitinib, bosutinib, cediranib,
dasatinib, erlotinib, gefitinib, imatinib, lapatinib, lestaurtinib,
nilotinib, semaxanib, sunitinib, toceranib, vandetanib, or
vatalanib, for example.
[0225] The therapeutic agent may comprise an anti-VEGF therapeutic
agent. Anti-VEGF therapies and agents can be used in the treatment
of certain cancers and in age-related macular degeneration.
Examples of anti-VEGF therapeutic agents suitable for use in
accordance with the embodiments described herein include one or
more of monoclonal antibodies such as bevacizumab (Avastin.TM.) or
antibody derivatives such as ranibizumab (Lucentis.TM.), or small
molecules that inhibit the tyrosine kinases stimulated by VEGF such
as lapatinib (Tykerb.TM.), sunitinib (Sutent.TM.), sorafenib
(Nexavar.TM.), axitinib, or pazopanib.
[0226] The therapeutic agent may comprise a therapeutic agent
suitable for treatment of dry AMD such as one or more of
Sirolimus.TM. (Rapamycin), Copaxone.TM. (Glatiramer Acetate),
Othera.TM., Complement C5aR blocker, Ciliary Neurotrophic Factor,
Fenretinide or Rheopheresis.
[0227] The therapeutic agent may comprise a therapeutic agent
suitable for treatment of wet AMD such as one or more of REDD14NP
(Quark), Sirolimus.TM. (Rapamycin), ATG003; Regeneron.TM. (VEGF
Trap) or complement inhibitor (POT-4).
[0228] The therapeutic agent may comprise a kinase inhibitor such
as one or more of bevacizumab (monoclonal antibody), BIBW 2992
(small molecule targeting EGFR/Erb2), cetuximab (monoclonal
antibody), imatinib (small molecule), trastuzumab (monoclonal
antibody), gefitinib (small molecule), ranibizumab (monoclonal
antibody), pegaptanib (small molecule), sorafenib (small molecule),
dasatinib (small molecule), sunitinib (small molecule), erlotinib
(small molecule), nilotinib (small molecule), lapatinib (small
molecule), panitumumab (monoclonal antibody), vandetanib (small
molecule)or E7080 (targeting VEGFR2/VEGFR2, small molecule
commercially available from Esai, Co.)
[0229] The amount of therapeutic agent within the therapeutic
device may comprise from about 0.01 mg to about 50 mg, for example
Lucentis.TM., so as to provide therapeutic amounts of the
therapeutic agent for the extended time, for example at least 30
days. The extended time may comprise at least 90 days or more, for
example at least 180 days or for example at least 1 year, at least
2 years or at least 3 years or more. The target threshold
therapeutic concentration of a therapeutic agent such as
Lucentis.TM. in the vitreous may comprise at least a therapeutic
concentration of 0.1 ug/mL. For example the target threshold
concentration may comprise from about 0.1 ug/mL to about 5 ug/mL
for the extended time, where the upper value is based upon
calculations shown in Example 9 using published data. The target
threshold concentration is drug dependent and thus may vary for
other therapeutic agents.
[0230] The delivery profile may be configured in many ways to
obtain a therapeutic benefit from the sustained release device. For
example, an amount of the therapeutic agent may be inserted into
the container at monthly intervals so as to ensure that the
concentration of therapeutic device is above a safety protocol or
an efficacy protocol for the therapeutic agent, for example with
monthly or less frequent injections into the container. The
sustained release can result in an improved delivery profile and
may result in improved results. For example, the concentration of
therapeutic agent may remain consistently above a threshold amount,
for example 0.1 ug/mL, for the extended time.
[0231] The insertion method may comprise inserting a dose into the
container of the therapeutic device. For example, a single
injection of Lucentis.TM. may be injected into the therapeutic
device.
[0232] The duration of sustained delivery of the therapeutic agent
may extend for twelve weeks or more, for example four to six months
from a single insertion of therapeutic agent into the device when
the device is inserted into the eye of the patient.
[0233] The therapeutic agent may be delivered in many ways so as to
provide a sustained release for the extended time. For example, the
therapeutic device may comprise a therapeutic agent and a binding
agent. The binding agent may comprise small particles configured to
couple releasably or reversibly to the therapeutic agent, such that
the therapeutic agent is released for the extended time after
injection into the vitreous humor. The particles can be sized such
that the particles remain in the vitreous humor of the eye for the
extended time.
[0234] The therapeutic agent may be delivered with a device
implanted in the eye. For example, the drug delivery device can be
implanted at least partially within the sclera of the eye, so as to
couple the drug delivery device to the sclera of the eye for the
extended period of time. The therapeutic device may comprise a drug
and a binding agent. The drug and binding agent can be configured
to provide the sustained release for the extended time. A membrane
or other diffusion barrier or mechanism may be a component of the
therapeutic device to release the drug for the extended time.
[0235] The lifetime of the therapeutic device and number of
injections can be optimized for patient treatment. For example, the
device may remain in place for a lifetime of 30 years, for example
with AMD patients from about 10 to 15 years. For example, the
device may be configured for an implantation duration of at least
two years, with 8 injections (once every three months) for
sustained release of the therapeutic agent over the two year
duration. The device may be configured for implantation of at least
10 years with 40 injections (once every three months) for sustained
release of the therapeutic agent.
[0236] The therapeutic device can be refilled in many ways. For
example, the therapeutic agent can be refilled into the device in
the physician's office.
[0237] The therapeutic device may comprise many configurations and
physical attributes, for example the physical characteristics of
the therapeutic device may comprise at least one of a drug delivery
device with a suture, positioning and sizing such that vision is
not impaired, and biocompatible material. The device may comprise a
reservoir capacity from about 0.005 cc to about 0.2 cc, for example
from about 0.01 cc to about 0.1 cc, and a device volume of no more
than about 2 cc. A vitrectomy may be performed for device volumes
larger than 0.1 cc. The length of the device may not interfere with
the patient's vision and can be dependent on the shape of the
device, as well as the location of the implanted device with
respect to the eye. The length of the device may also depend on the
angle in which the device is inserted. For example, a length of the
device may comprise from about 4 to 6 mm. Since the diameter of the
eye is about 24 mm, a device extending no more than about 6 mm from
the sclera into the vitreous may have a minimal effect on patient
vision.
[0238] Embodiments may comprise many combinations of implanted drug
delivery devices. The therapeutic device may comprise a drug and
binding agent. The device may also comprise at least one of a
membrane, an opening, a diffusion barrier, a diffusion mechanism so
as to release therapeutic amounts of therapeutic agent for the
extended time.
[0239] FIG. 1 shows an eye 10 suitable for incorporation of the
therapeutic device. The eye has a cornea 12 and a lens 22
configured to form an image on the retina 26. The cornea can extend
to a limbus 14 of the eye, and the limbus can connect to a sclera
24 of the eye. A conjunctiva 16 of the eye can be disposed over the
sclera. The lens can accommodate to focus on an object seen by the
patient. The eye has an iris 18 that may expand and contract in
response to light. The eye also comprises a choroid 28 disposed the
between the sclera 24 and the retina 26. The retina comprises the
macula 32. The eye comprises a pars plana 25, which comprises an
example of a region of the eye suitable for placement and
retention, for example anchoring, of the therapeutic device 100 as
described herein. The pars plana region may comprise sclera and
conjunctiva disposed between the retina and cornea. The therapeutic
device can be positioned so as to extend from the pars plana region
into the vitreous humor 30 to release the therapeutic agent. The
therapeutic agent can be released into the vitreous humor 30, such
that the therapeutic agent arrives at the retina and choroids for
therapeutic effect on the macula. The vitreous humor of the eye
comprises a liquid disposed between the lens and the retina. The
vitreous humor may comprise convection currents to deliver the
therapeutic agent to the macula.
[0240] FIG. 1A-1 shows a therapeutic device 100 implanted at least
partially within the sclera 24 of the eye 10 as in FIG. 1. The
therapeutic device may comprise a retention structure, for example
a protrusion, to couple the device to the sclera. The therapeutic
device may extend through the sclera into vitreous humor 30, such
that the therapeutic device can release the therapeutic agent into
the vitreous humor.
[0241] FIGS. 1A-1-1 and 1A-1-2 shows a therapeutic device 100
implanted under the conjunctiva 16 and extending through the sclera
24 to release a therapeutic agent 110 into vitreous humor 30 of the
eye 10 so as to treat the retina of the eye. The therapeutic device
100 may comprise a retention structure 120 such as a smooth
protrusion configured for placement along the sclera and under the
conjunctiva, such that the conjunctiva can cover the therapeutic
device and protect the therapeutic device 100. When the therapeutic
agent 110 is inserted into the device 100, the conjunctiva may be
lifted away, incised, or punctured with a needle to access the
therapeutic device. The eye may comprise an insertion of the tendon
27 of the superior rectus muscle to couple the sclera of the eye to
the superior rectus muscle. The device 100 may be positioned in
many locations of the pars plana region, for example away from
tendon 27 and one or more of posterior to the tendon, posterior to
the tendon, under the tendon, or with nasal or temporal placement
of the therapeutic device.
[0242] While the implant can be positioned in the eye in many ways,
work in relation to embodiments suggests that placement in the pars
plana region can release therapeutic agent into the vitreous to
treat the retina, for example therapeutic agent comprising an
active ingredient composed of large molecules.
[0243] Therapeutic agents 110 suitable for use with device 100
includes many therapeutic agents, for example as listed in Table
1A, herein below. The therapeutic agent 110 of device 100 may
comprise one or more of an active ingredient of the therapeutic
agent, a formulation of the therapeutic agent, a commercially
available formulation of the therapeutic agent, a physician
prepared formulation of therapeutic agent, a pharmacist prepared
formulation of the therapeutic agent, or a commercially available
formulation of therapeutic agent having an excipient. The
therapeutic agent may be referred to with generic name or a trade
name, for example as shown in Table 1A.
[0244] The therapeutic device 100 can be implanted in the eye to
treat the eye for as long as is helpful and beneficial to the
patient. For example the device can be implanted for at least about
5 years, such as permanently for the life of the patient.
Alternatively or in combination, the device can be removed when no
longer helpful or beneficial for treatment of the patient.
[0245] FIG. 1A-2 shows structures of therapeutic device 100
configured for placement in an eye as in FIGS. 1A-1, 1A-1-1 and
1A-1-2. The device may comprise retention structure 120 to couple
the device 100 to the sclera, for example a protrusion disposed on
a proximal end of the device. The device 100 may comprise a
container 130 affixed to the retention structure 120. An active
ingredient, for example therapeutic agent 110, can be contained
within a reservoir 140, for example a chamber 132 defined by a
container 130 of the device. The container 130 may comprise a
porous structure 150 comprising a porous material 152, for example
a porous glass frit 154, and a barrier 160 to inhibit release of
the therapeutic agent, for example non-permeable membrane 162. The
non-permeable membrane 162 may comprise a substantially
non-permeable material 164. The non-permeable membrane 162 may
comprise an opening 166 sized to release therapeutic amounts of the
therapeutic agent 110 for the extended time. The porous structure
150 may comprise a thickness 150T and pore sizes configured in
conjunction with the opening 166 so as to release therapeutic
amounts of the therapeutic agent for the extended time. The
container 130 may comprise reservoir 140 having a chamber with a
volume 142 sized to contain a therapeutic quantity of the
therapeutic agent 110 for release over the extended time. The
device may comprise a needle stop 170. Proteins in the vitreous
humor may enter the device and compete for adsorption sites on the
porous structure and thereby may contribute to the release of
therapeutic agent. The therapeutic agent 110 contained in the
reservoir 140 can equilibrate with proteins in the vitreous humor,
such that the system is driven towards equilibrium and the
therapeutic agent 110 is released in therapeutic amounts.
[0246] The non-permeable membrane 162, the porous material 152, the
reservoir 140, and the retention structure 120, may comprise many
configurations to deliver the therapeutic agent 110. The
non-permeable membrane 162 may comprise an annular tube joined by a
disc having at least one opening formed thereon to release the
therapeutic agent. The porous material 152 may comprise an annular
porous glass frit 154 and a circular end disposed thereon. The
reservoir 140 may be shape-changing for ease of insertion, i.e. it
may assume a thin elongated shape during insertion through the
sclera and then assume an extended, ballooned shape, once it is
filled with therapeutic agent.
[0247] The porous structure 150 can be configured in many ways to
release the therapeutic agent in accordance with an intended
release profile. For example, the porous structure may comprise a
porous structure having a plurality of openings on a first side
facing the reservoir and a plurality of openings on a second side
facing the vitreous humor, with a plurality of interconnecting
channels disposed therebetween so as to couple the openings of the
first side with the openings of the second side, for example a
sintered rigid material. The porous structure 150 may comprise one
or more of a permeable membrane, a semi-permeable membrane, a
material having at least one hole disposed therein, nano-channels,
nano-channels etched in a rigid material, laser etched
nano-channels, a capillary channel, a plurality of capillary
channels, one or more tortuous channels, tortuous microchannels,
sintered nano-particles, an open cell foam or a hydrogel such as an
open cell hydrogel.
[0248] FIG. 1A-2-1 shows therapeutic device 100 loaded into an
insertion cannula 210 of an insertion apparatus 200, in which the
device 100 comprises an elongate narrow shape for insertion into
the sclera, and in which the device is configured to expand to a
second elongate wide shape for retention at least partially in the
sclera;
[0249] FIG. 1A-2-2 shows a therapeutic device 100 comprising
reservoir 140 suitable for loading in a cannula, in which the
reservoir 140 comprises an expanded configuration.
[0250] FIG. 1B shows therapeutic device 100 configured for
placement in an eye as in FIG. 1A-1 and 1A-1-1. The device
comprises retention structure 120 to couple to the sclera, for
example flush with the sclera, and the barrier 160 comprises a tube
168. An active ingredient 112 comprising the therapeutic agent 110
is contained within tube 168 comprising non-permeable material 164.
A porous material 152 is disposed at the distal end of the tube 168
to provide a sustained release of the therapeutic agent at
therapeutic concentrations for the extended period. The
non-permeable material 164 may extend distally around the porous
material 152 so as to define an opening to couple the porous
material 152 to the vitreous humor when the device is inserted into
the eye.
[0251] The tube 168 and retention structure 120 may be configured
to receive a glass rod, which is surface treated, and the glass rod
can be injected with therapeutic agent. When the therapeutic agent
has finished elution for the extended time, the rod can be replaced
with a new rod.
[0252] The device 100 may comprise therapeutic agent and a carrier,
for example a binding medium comprising a binding agent to deliver
the therapeutic agent. The therapeutic agent can be surrounded with
a column comprising a solid support that is eroded away.
[0253] FIG. 1C shows a therapeutic device configured for placement
in an eye as in FIG. 1A-1 and 1A-1-1. A binding medium 192
comprising a binding agent 190 such as glass wool may be loaded
with therapeutic agent 110 prior to injection into the device
through an access port 180. The device 100 may comprise binding,
leak, and barrier functions to deliver the therapeutic agent for
the extended time. The binding medium 192 and therapeutic agent 110
can be aspirated to replace the binding medium and therapeutic
agent. The binding medium can be at least one of flushed or
replaced when at least majority of the therapeutic agent has been
released, such that additional therapeutic agent can be delivered
from a second, injected binding medium comprising therapeutic
agent. A membrane 195 can be disposed over the periphery of the
therapeutic device 100. The membrane 195 may comprise
methylcellulose, regenerated cellulose, cellulose acetate, nylon,
polycarbonate, poly(tetrafluoroethylene) (PTFE), polyethersulfone,
and polyvinylidene difluoride (PVDF). The therapeutic device may
comprise barrier 160 shaped such that opening 166 comprises an exit
port. The therapeutic agent may be released through at least one of
a diffusion mechanism or convection mechanism. The number, size,
and configuration of exit ports may determine the release rate of
the therapeutic agent. The exit port may comprise a convection
port, for example at least one of an osmotically driven convection
port or a spring driven convection port. The exit port may also
comprise a tubular path to which the therapeutic agent may
temporarily attach, and then be released under certain physical or
chemical conditions.
[0254] FIG. 1C-A shows at least one exit port 167, the exit port
can be disposed on the device 100 to allow liquid to flow from
inside the device outward, for example when fluid is injected into
an injection port 182 of the device or when an insert such as a
glass frit is inserted into the device. The therapeutic device may
comprise an access port 180 for injection and/or removal, for
example a septum. Additionally or in the alternative, when the
therapeutic device is refilled, the contents of the device may be
flushed into the vitreous of the eye.
[0255] FIG. 1C-1 shows a method of removing a binding agent 194. A
needle 189 coupled to a syringe 188 of an injector 187 can be
inserted into an access port 180 of the therapeutic device 100. The
binding agent 194 can be aspirated with a needle.
[0256] FIG. 1C-2 shows a method of inserting the therapeutic agent
110 with a second binding agent 190 having the therapeutic agent
110 bound thereon. The therapeutic agent can be injected into a
container 130 of the device for sustained release over the extended
time.
[0257] FIG. 1C-3 shows syringe being filled with a formulation of
therapeutic agent for injection into the therapeutic device. The
needle 189 coupled to syringe 188 of injector 187 can be used to
draw therapeutic agent 110 from a container 110C. The container
110C may comprise a commercially available container, such as a
bottle with a septum, a single dose container, or a container
suitable for mixing formulations. A quantity 110V of therapeutic
agent 110 can be drawn into injector 187 for injection into the
therapeutic device 100 positioned within the eye. The quantity 110V
may comprise a predetermined quantity, for example based on the
volume of the container of the therapeutic device 110 and an
intended injection into the vitreous humor. The example the
quantity 110V may exceed the volume of the container so as to
inject a first portion of quantity 110V into the vitreous humor
through the therapeutic device and to contain a second portion of
quantity 110V within the container of the therapeutic device 110.
Container 110C may comprise a formulation 110F of the therapeutic
agent 110. The formulation 110F may comprise a commercially
available formulations of therapeutic agent, for example
therapeutic agents as described herein and with reference to Table
1A. Non-limiting examples of commercially available formulations
that may be suitable for use in accordance with the embodiments
described herein include Lucentis.TM. and Triamcinolone, for
example. The formulation 110F may be a concentrated or diluted
formulation of a commercially available therapeutic agent, for
example Avastin.TM. The osmolarity and tonicity of the vitreous
humor can be within a range from about 290 to about 320. For
example, a commercially available formulation of Avastin.TM. may be
diluted so as to comprise a formulation having an osmolarity and
tonicity substantially similar to the osmolarity and tonicity of
the vitreous humor, for example within a range from about 280 to
about 340, for example about 300 mOsm. While the therapeutic agent
110 may comprise an osmolarity and tonicity substantially similar
to the vitreous humor, the therapeutic agent 110 may comprise a
hyper osmotic solution relative to the vitreous humor or a hypo
osmotic solution relative to the vitreous humor. A person or
ordinary skill in the art can conduct experiments based on the
teachings described herein so as to determine empirically the
formulation and osmolarity of the therapeutic agent to provide
release of therapeutic agent for an extended time.
[0258] For example, in the United States of America, Lucentis.TM.
(active ingredient ranibizumab) is supplied as a preservative-free,
sterile solution in a single-use glass vial designed to deliver
0.05 mL of 10 mg/mL Lucentis.TM. aqueous solution with 10 mM
histidine HCl, 10% .alpha., .alpha.-trehalose dihydrate, 0.01%
polysorbate 20, at pH 5.5. In Europe, the Lucentis.TM. formulation
can be substantially similar to the formulation of the United
States.
[0259] For example, the sustained release formulation of
Lucentis.TM. in development by Genentech and/or Novartis, may
comprise the therapeutic agent injected in to the device 100. The
sustained release formulation may comprise particles comprising
active ingredient.
[0260] For example, in the United States, Avastin.TM. (bevacizumab)
is approved as an anticancer drug and in clinical trials are
ongoing for AMD. For cancer, the commercial solution is a pH 6.2
solution for intravenous infusion. Avastin.TM. is supplied in 100
mg and 400 mg preservative-free, single-use vials to deliver 4 mL
or 16 mL of Avastin.TM. (25 mg/mL). The 100 mg product is
formulated in 240 mg .alpha., .alpha.-trehalose dihydrate, 23.2 mg
sodium phosphate (monobasic, monohydrate), 4.8 mg sodium phosphate
(dibasic, anhydrous), 1.6 mg polysorbate 20, and Water for
Injection, USP. The 400 mg product is formulated in 960 mg .alpha.,
.alpha.-trehalose dihydrate, 92.8 mg sodium phosphate (monobasic,
monohydrate), 19.2 mg sodium phosphate (dibasic, anhydrous), 6.4 mg
polysorbate 20, and Water for Injection, USP. The commercial
formulations are diluted in 100 mL of 0.9% sodium chloride before
administration and the amount of the commercial formulation used
varies by patient and indication. Based on the teachings described
herein, a person of ordinary skill in the art can determine
formulations of Avastin.TM. to inject into therapeutic device 100.
In Europe, the Avastin.TM. formulation can be substantially similar
to the formulation of the United States.
[0261] For example, in the United States, there are 2 forms of
Triamcinolone used in injectable solutions, the acetonide and the
hexacetonide. The acetamide is approved for intravitreal injections
in the U.S. The acetamide is the active ingredient in TRIVARIS
(Allergan), 8 mg triamcinolone acetonide in 0.1 mL (8% suspension)
in a vehicle containing w/w percents of 2.3% sodium hyaluronate;
0.63% sodium chloride; 0.3% sodium phosphate, dibasic; 0.04% sodium
phosphate, monobasic; and water, pH 7.0 to 7.4 for injection. The
acetamide is also the active ingredient in Triesence.TM. (Alcon), a
40 mg/ml suspension.
[0262] A person of ordinary skill in the art can determine the
osmolarity for these formulations. The degree of dissociation of
the active ingredient in solution can be determined and used to
determined differences of osmolarity from the molarity in these
formulations. For example, considering at least some of the
formulations may be concentrated (or suspensions), the molarity can
differ from the osmolarity.
[0263] The formulation of therapeutic agent injected into
therapeutic device 100 may comprise many known formulations of
therapeutic agents, and the formulation therapeutic agent comprises
an osmolarity suitable for release for an extended time from device
100. Table 1B shows examples of osmolarity (Osm) of saline and some
of the commercially formulations of Table 1A.
TABLE-US-00001 TABLE 1B Summary of Calculations Description Osm (M)
Saline (0.9%) 0.308 Phosphate Buffered Saline (PBS) 0.313 Lucentis
.TM. 0.289 Avastin .TM. 0.182 Triamcinolone Acetonide
(Trivaris-Allergan) 0.342 Triamcinolone Acetonide (Triessence -
Alcon) Isotonic* Triamcinolone Acetonide (Kenalog - Apothecon)
Isotonic* *As described in package insert
[0264] The vitreous humor of the eye comprises an osmolarity of
about 290 mOsm to about 320 mOsm. Formulations of therapeutic agent
having an osmolarity from about 280 mOsm to about 340 mOsm are
substantially isotonic and substantially iso-osmotic with respect
to the vitreous humor of the eye. Although the formulations listed
in Table 1B are substantially iso-osmotic and isotonic with respect
to the vitreous of the eye and suitable for injection into the
therapeutic device, the formulation of the therapeutic agent
injected into the therapeutic device can be hypertonic
(hyper-osmotic) or hypotonic (hypo-osmotic) with respect to the
tonicity and osmolarity of the vitreous. Work in relation to
embodiments suggests that a hyper-osmotic formulation may release
the active ingredient of the therapeutic agent into the vitreous
somewhat faster initially when the solutes of the injected
formulation equilibrate with the osmolarity of the vitreous, and
that a hypo-osmotic formulation such as Avastin.TM. may release the
active ingredient of the therapeutic agent into the vitreous
somewhat slower initially when the solutes of the injected
formulation equilibrate with the eye. A person of ordinary skill in
the art can conduct experiments based on the teaching described
herein to determine empirically the appropriate reservoir chamber
volume and porous structure for a formulation of therapeutic agent
disposed in the reservoir chamber, so as to release therapeutic
amounts of the therapeutic agent for an extended time and to
provide therapeutic concentrations of therapeutic agent in the
vitreous within a range of therapeutic concentrations that is above
the minimum inhibitory concentration for the extended time.
[0265] FIG. 1D shows a therapeutic device 100 configured for
placement in an eye as in FIG. 1A-1 and 1A-1-1, in which the device
comprises a plurality of chambers and channels connecting the
chambers so as to linearize the release of the therapeutic agent. A
first chamber 132A may comprise a reservoir having a first volume
to contain the therapeutic quantity of the therapeutic agent. For
example, the therapeutic agent comprises the active ingredient
contained within the reservoir. A second chamber 132B can be
disposed distally to the first chamber, with a first opening
connecting the first chamber and the second chamber. The
therapeutic agent can diffuse through the first opening into the
second chamber. The second chamber comprises a second volume, such
that therapeutic agent is temporarily stored in the second chamber
so as to linearize, for example toward zero order, the delivery of
the therapeutic agent. A second opening can extend from the second
chamber toward the vitreous humor. The first opening, the second
opening and the second volume can be sized so as to linearize the
delivery of the therapeutic agent for the sustained release at
therapeutic levels for the extended time. More than one therapeutic
agent can be inserted into the therapeutic device. In such a case
the two or more therapeutic agents may be mixed together or
injected into separate chambers.
[0266] Additional chambers and openings can be disposed on the
device to linearize the delivery of the drug. For example, a third
chamber can be disposed distally to the second chamber. The second
opening can couple the second chamber to the third chamber. For
example, a fourth chamber can be disposed distally to the third
chamber, a third opening can connect the third chamber and the
fourth chamber.
[0267] Additionally or in the alternative, the therapeutic device
may comprise at least one gate to provide for sustained drug
delivery. The gate can be moved from "closed" to "open" position
using magnetism or by applying electrical current. For example the
gates can slide or twist. The gates can be spring-loaded, and may
comprise a pump that can be re-loaded. The gates may comprise an
osmotic pump.
[0268] FIG. 1E shows a therapeutic device configured for placement
in an eye as in FIGS. 1A-1 and 1A-1-1, in which the device
comprises 100 needle stop 170 located at the bottom of the
therapeutic device. The needle stop that may be included in the
therapeutic device to keep the injection needle 189 from
penetrating through and possibly damaging the exit port(s) 166 of
the therapeutic device 100. The needle stop will desirably be made
of a material of sufficient rigidity to prevent the advancement of
the injection needle past a certain level in the therapeutic
device. Additionally or in the alternative, the length of the
injector's needle may be designed so that it may not penetrate
through and possibly damage the exit port(s) of the therapeutic
device.
[0269] As shown in FIGS. 1E and 1E-1, the needle stop 170 may be
positioned at the posterior end of the therapeutic device. FIGS.
1E-2, 1E-3 and 1E-3-1 show other embodiments that may include
needle stops placed in the middle of the device. The needle stop
may be designed in such a manner as to function as a flow diverter
for the therapeutic agent. The shape of the needle stop may
encourage the mixing of the therapeutic agent with the rest of the
fluids present in the inner chamber(s) of the therapeutic
device.
[0270] FIG. 1E-1 shows a therapeutic device configured for
placement in an eye as in FIGS. 1A-1 and 1A-1-1, in which the
device comprises needle stop 170 located at the bottom of the
therapeutic device and the shape of the device encourages the
movement of the therapeutic agent within the chamber of the
therapeutic device 100;
[0271] FIG. 1E-2 shows a therapeutic device configured for
placement in an eye as in FIGS. 1A-1 and 1A-1-1, in which the
device comprises needle stop 170 located in the middle of the
therapeutic device;
[0272] FIG. 1E-3 shows a therapeutic device configured for
placement in an eye as in FIGS. 1A-1 and 1A-1-1, in which the
device comprises needle stop 170 located in the middle of the
therapeutic device and the shape of the device encourages the
movement of the therapeutic agent within the chamber of the
therapeutic device;
[0273] FIG. 1E-3-1 shows a top view of the therapeutic device
configured for placement in an eye as in FIGS. 1E-3;
[0274] FIG. 2 shows an access port 180 suitable for incorporation
with the therapeutic device 100. The access port 180 may be
combined with the therapeutic devices described herein, for example
with reference to FIGS. 1A-1 to 1D. The access port may be disposed
on a proximal end of the device. The access port 180 may comprise
an opening formed in the retention structure 120 with a penetrable
barrier 184 comprising a septum 186 disposed thereon. The access
port may 180 be configured for placement under the conjunctiva 16
of the patient and above the sclera 24.
[0275] FIG. 3A shows a collar 128 suitable for incorporation with
the therapeutic device 100. The retention structure 120 configured
to couple to the sclera 24 may comprise the collar 128. The collar
may comprise an expandable collar.
[0276] FIG. 3B shows biocompatible material impregnated with an
anti-bacterial agent 310 on the therapeutic device 100 to inhibit
bacterial growth along the device from the sclera to the vitreous
humor. The biocompatible material may comprise collagen, for
example a collagen sponge 312, and the anti-bacterial agent may
comprise silver impregnated in the collagen. The biocompatible
material impregnated with the bactericide agent may extend around
at least a portion of the outer surface of the device. The
anti-bacterial agent may comprise a portion of the retention
structure 120, such that the anti-bacterial agent is disposed at
least partially within the sclera when the device is inserted into
the eye.
[0277] FIG. 4A shows released antibodies comprising antibody
fragments 410 and a substrate 420 comprising binding agent 190, and
FIG. 4B shows an antibody fragments 410 reversibly bound to a
substrate 420 with binding agent 190, in accordance with
embodiments of the present invention. The anti-body fragments can
be reversibly bound to the substrate comprising the binding agent,
such that the bound antibody fragments are in equilibrium with the
unbound antibody fragments. One of ordinary skill in the art will
recognize many substrates comprising binding agent to reversibly
bind at least a portion of an antibody based on the teachings
described herein. Examples of binding media may include
particulates used in chromatography, such as: Macro-Prep t-Butyl
HIC Support, Macro-Prep DEAE Support, CHT Ceramic, Hydroxyapatite
Type I, Macro-Prep CM Support, Macro-Prep Methyl HIC Support,
Macro-Prep Ceramic Hydroxapatite Type II, UNOsphere S Cation
Exchange Support, UNOsphere Q Strong Anion Exchange Support,
Macro-Prep High-S Support, and Macro-Prep High-Q Support.
Additional media to test for binding include ion exchange and
bioaffinity chromatography media based on a hydrophilic polymeric
support (GE Healthcare) that bind proteins with high capacity, and
a hydrophilic packing material from Harvard Apparatus made from
poly(vinyl alcohol) that binds more protein than silica. Other
candidates would be known to those knowledgeable in the art.
[0278] FIG. 5A shows therapeutic device 100 coupled to injector 187
to insert therapeutic agent 110 into container 130 of the device.
The injector 187 may comprise needle 189 coupled to a syringe
188.
[0279] FIG. 5A-1 shows a therapeutic device 100 coupled to an
injector 187 to inject and remove material from the device. The
injector may comprise needle 189 having a first lumen 189A and a
second lumen 189B configured to insert into a container of the
device. The injector may simultaneously inject 510 therapeutic
agent into and withdraw 520 liquid from the device. The injector
may comprise a first one way valve and a second one way valve
coupled to the first lumen and the second lumen, respectively.
[0280] FIG. 5B shows a therapeutic device comprising a microloop
channel 530. The microloop channel may extend to a first port 530A
and a second port 530B, such the therapeutic agent can be injected
into the first port, for example with a binding agent, and flowable
material, for example liquid comprising binding agent, can be drawn
from the microloop channel 530.
[0281] FIG. 5C-1 shows therapeutic device 100 comprising a tortuous
channel 540. The tortuous channel may comprise extend from a first
port 540A to a second port 540B, such that the therapeutic agent
can be injected into the first port and flowable material, for
example liquid comprising the binding agent, can be drawn from the
second channel.
[0282] FIG. 5C-2 shows a therapeutic device comprising a tortuous
coiled channel 550. The coiled channel 550 can extend to an exit
port 552. A needle 189 can be inserted into the port 180 to inject
therapeutic agent into device 100.
[0283] FIG. 5D shows an expandable and contactable structure 562 to
retain the therapeutic agent and an outer rigid casing 560 to
couple to the sclera. The expandable structure 562 may comprise a
membrane, such as at least one of a bag, a balloon, a flexible
reservoir, a diaphragm, or a bag. The outer rigid casing may extend
substantially around the structure 562 and may comprise an opening
to release liquid into the vitreous humor when the structure is
expanded and to draw vitreous humor inside a chamber of the casing
when material is drawn from the structure and the structure
contacts.
[0284] FIGS. 5E shows a membrane 550 disposed over an exit port 552
of therapeutic device 100.
[0285] FIG. 5F shows therapeutic device 100 comprising a tubular
membrane 572 clamped onto the therapeutic device over side ports
570 of device 100.
[0286] When the protective membranes have pores of 0.2 um diameter,
they are 20 or more times larger than the proteins of interest,
which may comprise a model for delivery of the therapeutic agent.
For example, molecular weights and diameters of models of proteins
of therapeutic interest are:
TABLE-US-00002 (a) IgG 150 kDa 10.5 nm (b) BSA 69 kDa 7.2 nm (c)
Fab fragment 49 kDa hydrodynamic diameter not reported of IgG
[0287] Therefore, solutions of therapeutic compounds in the size
range of IgG and BSA should flow relatively easily through 0.2 um
pore size protective membranes used to stop passage of bacterial
and other cells.
[0288] Binding Materials/Agents may comprise at least one of a
chemical binding agent/material, a structural binding agent or
material, or an electrostatic binding agent or material. The types
of binding agent may comprise a classification composed of
non-biodegradable material, for example at glass beads, glass wool
or a glass rod. A surface can be derivatized with at least one
functional group so as to impart the binding agent or material with
the potential for at least one of ionic, hydrophobic, or
bioaffinity binding to at least one therapeutic compound.
[0289] The binding agent may comprise a biodegradable material. For
example, the biodegradation, binding, or a combination of the
previous processes may control the diffusion rate.
[0290] The binding agent may comprise ion exchange, and the ion
exchange may comprise at least one of a functional group, a pH
sensitive binding or a positive or negative charge. For example,
ion exchange with at least one of diethylaminoethyl or
carboxymethyl functional groups.
[0291] The binding agent may comprise a pH sensitive binding agent.
For example the binding agent can be configured to elute
therapeutic agent at a pH of 7, and to bind the therapeutic agent
at a pH from about 4 to about 6.5. A cation exchange binding agent
can be configured, for example, such that at a pH of 7, the net
negative charge of the binding agent decreases causing a decrease
in binding of the positively charged drug and release of the
therapeutic agent. A target buffer can be provided with the binding
agent to reversibly couple the binding agent to the therapeutic
agent. The rate of release can be controlled, for example slowed
down, by using insolubility of the buffer in the vitreous.
Alternatively or in combination the elution can be limited by using
a porous membrane or a physical property such as a size of an
opening.
[0292] The ion exchange may comprise positive or negative ion
exchange.
[0293] The binding agent may comprise hydrophobic interaction. For
example, the binding agent may comprise at least one binding to
hydrophobic pockets, for example at least one of methyl, ethyl,
propyl, butyl, t-butyl or phenyl functional groups.
[0294] The binding agent may comprise affinity, for example at
least one of a macromolecular affinity or a metal chelation
affinity. Examples can include a hydroxyapatite, or chelated metal,
for example zinc. Iminodiacetic acid can be chelated with zinc.
[0295] The binding agent may comprise at least one of the following
functions: charging, recharging or elution. The charging may
comprise a porous material injected therein so as to release the
active ingredient. The porous matter may have an extremely large
inert surface area, which surface area is available for binding.
The recharging may comprise removing carrier+therapeutic agent; and
adding freshly "charged" carrier+therapeutic agent.
[0296] The elution may comprise a byproduct, for example unbound
binding agent that can be removed. For example, diffusion (plug
flow) of vitreous to change conditions, e.g. pH to reduce
interaction of therapeutic agent+carriers.
[0297] Additionally or in the alternative, a sustained drug
delivery system of the therapeutic agent may comprise drug delivery
packets, e.g. microspheres, that are activated. The packets can be
activated with at least one of photochemical activation, thermal
activation or biodegradation.
[0298] The therapeutic device may comprise at least one structure
configured to provide safety precautions. The device may comprise
at least one structure to prevent at least one of macrophage or
other immune cell within the reservoir body; bacterial penetration;
or retinal detachment.
[0299] The therapeutic device may be configured for other
applications in the body. Other routes of administration of drugs
may include at least one of intraocular, oral, subcutaneous,
intramuscular, intraperitoneal, intranasal, dermal, intrathecal,
intravascular, intra articular, pericardial, intraluminal in organs
and gut or the like.
[0300] Conditions that may be treated and/or prevented using the
drug delivery device and method described herein may include at
least one of the following: hemophilia and other blood disorders,
growth disorders, diabetes, leukemia, hepatitis, renal failure, HIV
infection, hereditary diseases such as cerebrosidase deficiency and
adenosine deaminase deficiency, hypertension, septic shock,
autoimmune diseases such as multiple sclerosis, Graves disease,
systemic lupus erythematosus and rheumatoid arthritis, shock and
wasting disorders, cystic fibrosis, lactose intolerance, Crohn's
disease, inflammatory bowel disease, gastrointestinal or other
cancers, degenerative diseases, trauma, multiple systemic
conditions such as anemia, and ocular diseases such as, for
example, retinal detachment, proliferative retinopathy,
proliferative diabetic retinopathy, degenerative disease, vascular
diseases, occlusions, infection caused by penetrating traumatic
injury, endophthalmitis such as endogenous/systemic infection,
post-operative infections, inflammations such as posterior uveitis,
retinitis or choroiditis and tumors such as neoplasms and
retinoblastoma.
[0301] Examples of therapeutic agents 110 that may be delivered by
the therapeutic device 100 are described in Table 1A and may
include Triamcinolone acetonide, Bimatoprost (Lumigan), Ranibizumab
(Lucentis.TM.), Travoprost (Travatan, Alcon), Timolol (Timoptic,
Merck), Levobunalol (Betagan, Allergan), Brimonidine (Alphagan,
Allergan), Dorzolamide (Trusopt, Merck), Brinzolamide (Azopt,
Alcon). Additional examples of therapeutic agents that may be
delivered by the therapeutic device include antibiotics such as
tetracycline, chlortetracycline, bacitracin, neomycin, polymyxin,
gramicidin, cephalexin, oxytetracycline, chloramphenicol kanamycin,
rifampicin, ciprofloxacin, tobramycin, gentamycin, erythromycin and
penicillin; antifungals such as amphotericin B and miconazole;
anti-bacterials such as sulfonamides, sulfadiazine, sulfacetamide,
sulfamethizole and sulfisoxazole, nitrofurazone and sodium
propionate; antivirals such as idoxuridine, trifluorotymidine,
acyclovir, ganciclovir and interferon; antiallergenics such as
sodium cromoglycate, antazoline, methapyriline, chlorpheniramine,
pyrilamine, cetirizine and prophenpyridamine; anti-inflammatories
such as hydrocortisone, hydrocortisone acetate, dexamethasone,
dexamethasone 21-phosphate, fluocinolone, medrysone, prednisolone,
prednisolone 21-phosphate, prednisolone acetate, fluoromethalone,
betamethasone, and triamcinolone; non-steroidal anti-inflammatories
such as salicylate, indomethacin, ibuprofen, diclofenac,
flurbiprofen and piroxicam; decongestants such as phenylephrine,
naphazoline and tetrahydrozoline; miotics and anticholinesterases
such as pilocarpine, salicylate, acetylcholine chloride,
physostigmine, eserine, carbachol, diisopropyl fluorophosphate,
phospholine iodide and demecarium bromide; mydriatics such as
atropine sulfate, cyclopentolate, homatropine, scopolamine,
tropicamide, eucatropine and hydroxyamphetamine; sypathomimetics
such as epinephrine; antineoplastics such as carmustine, cisplatin
and fluorouracil; immunological drugs such as vaccines and immune
stimulants; hormonal agents such as estrogens, estradiol,
progestational, progesterone, insulin, calcitonin, parathyroid
hormone and peptide and vasopressin hypothalamus releasing factor;
beta adrenergic blockers such as timolol maleate, levobunolol Hcl
and betaxolol Hcl; growth factors such as epidermal growth factor,
fibroblast growth factor, platelet derived growth factor,
transforming growth factor beta, somatotropin and fibronectin;
carbonic anhydrase inhibitors such as dichlorophenamide,
acetazolamide and methazolamide and other drugs such as
prostaglandins, antiprostaglandins and prostaglandin precursors.
Other therapeutic agents known to those skilled in the art which
are capable of controlled, sustained release into the eye in the
manner described herein are also suitable for use in accordance
with embodiments of the present invention.
[0302] The therapeutic agent 110 may comprise one or more of the
following: Abarelix, Abatacept, Abciximab, Adalimumab, Aldesleukin,
Alefacept, Alemtuzumab, Alpha-1-proteinase inhibitor, Alteplase,
Anakinra, Anistreplase, Antihemophilic Factor, Antithymocyte
globulin, Aprotinin, Arcitumomab, Asparaginase, Basiliximab,
Becaplermin, Bevacizumab, Bivalirudin, Botulinum Toxin Type A,
Botulinum Toxin Type B, Capromab, Cetrorelix, Cetuximab,
Choriogonadotropin alfa, Coagulation Factor IX, Coagulation factor
VIIa, Collagenase, Corticotropin, Cosyntropin, Cyclosporine,
Daclizumab, Darbepoetin alfa, Defibrotide, Denileukin diftitox,
Desmopressin, Dornase Alfa,Drotrecogin alfa, Eculizumab,
Efalizumab, Enfuvirtide, Epoetin alfa, Eptifibatide, Etanercept,
Exenatide, Felypressin, Filgrastim, Follitropin beta, Galsulfase,
Gemtuzumab ozogamicin, Glatiramer Acetate, Glucagon recombinant,
Goserelin, Human Serum Albumin, Hyaluronidase, Ibritumomab,
Idursulfase, Immune globulin, Infliximab, Insulin Glargine
recombinant, Insulin Lyspro recombinant, Insulin recombinant,
Insulin, porcine, Interferon Alfa-2a, Recombinant, Interferon
Alfa-2b, Recombinant, Interferon alfacon-1, Interferonalfa-n1,
Interferon alfa-n3, Interferon beta-1b, Interferon gamma-1b,
Lepirudin, Leuprolide, Lutropin alfa, Mecasermin, Menotropins,
Muromonab, Natalizumab, Nesiritide, Octreotide, Omalizumab,
Oprelvekin, OspA lipoprotein, Oxytocin, Palifermin, Palivizumab,
Panitumumab, Pegademase bovine, Pegaptanib, Pegaspargase,
Pegfilgrastim, Peginterferon alfa-2a, Peginterferon alfa-2b,
Pegvisomant, Pramlintide, Ranibizumab, Rasburicase, Reteplase,
Rituximab, Salmon Calcitonin, Sargramostim, Secretin, Sermorelin,
Serum albumin iodonated, Somatropin recombinant, Streptokinase,
Tenecteplase, Teriparatide, Thyrotropin Alfa, Tositumomab,
Trastuzumab, Urofollitropin, Urokinase, or Vasopressin. The
molecular weights of the molecules and indications of these
therapeutic agents are set for below in Table 1A, below.
[0303] The therapeutic agent 110 may comprise one or more of
compounds that act by binding members of the immunophilin family of
cellular proteins. Such compounds are known as "immunophilin
binding compounds." Immunophilin binding compounds include but are
not limited to the "limus" family of compounds. Examples of limus
compounds that may be used include but are not limited to
cyclophilins and FK506-binding proteins (FKBPs), including
sirolimus (rapamycin) and its water soluble analog SDZ-RAD,
tacrolimus, everolimus, pimecrolimus, CCI-779 (Wyeth), AP23841
(Ariad), and ABT-578 (Abbott Laboratories).
[0304] The limus family of compounds may be used in the
compositions, devices and methods for the treatment, prevention,
inhibition, delaying the onset of, or causing the regression of
angiogenesis-mediated diseases and conditions of the eye, including
choroidal neovascularization. The limus family of compounds may be
used to prevent, treat, inhibit, delay the onset of, or cause
regression of AMD, including wet AMD. Rapamycin may be used to
prevent, treat, inhibit, delay the onset of, or cause regression of
angiogenesis-mediated diseases and conditions of the eye, including
choroidal neovascularization. Rapamycin may be used to prevent,
treat, inhibit, delay the onset of, or cause regression of AMD,
including wet AMD.
[0305] The therapeutic agent 110 may comprise one or more of:
pyrrolidine, dithiocarbamate (NF.kappa.B inhibitor); squalamine;
TPN 470 analogue and fumagillin; PKC (protein kinase C) inhibitors;
Tie-1 and Tie-2 kinase inhibitors; inhibitors of VEGF receptor
kinase; proteosome inhibitors such as Velcade..TM.. (bortezomib,
for injection; ranibuzumab (Lucentis..TM..) and other antibodies
directed to the same target; pegaptanib (Macugen..TM..);
vitronectin receptor antagonists, such as cyclic peptide
antagonists of vitronectin receptor-type integrins;
.alpha.-v/.beta.-3 integrin antagonists; .alpha-v/.beta.-1 integrin
antagonists; thiazolidinediones such as rosiglitazone or
troglitazone; interferon, including .gamma.-interferon or
interferon targeted to CNV by use of dextran and metal
coordination; pigment epithelium derived factor (PEDF); endostatin;
angiostatin; tumistatin; canstatin; anecortave acetate; acetonide;
triamcinolone; tetrathiomolybdate; RNA silencing or RNA
interference (RNAi) of angiogenic factors, including ribozymes that
target VEGF expression; Accutane..TM.. (13-cis retinoic acid); ACE
inhibitors, including but not limited to quinopril, captopril, and
perindozril; inhibitors of mTOR (mammalian target of rapamycin);
3-aminothalidomide; pentoxifylline; 2-methoxyestradiol;
colchicines; AMG-1470; cyclooxygenase inhibitors such as nepafenac,
rofecoxib, diclofenac, rofecoxib, NS398, celecoxib, vioxx, and
(E)-2-alkyl-2(4-methanesulfonylphenyl)-1-phenylethene; t-RNA
synthase modulator; metalloprotease 13 inhibitor;
acetylcholinesterase inhibitor; potassium channel blockers;
endorepellin; purine analog of 6-thioguanine; cyclic peroxide
ANO-2; (recombinant) arginine deiminase;
epigallocatechin-3-gallate; cerivastatin; analogues of suramin;
VEGF trap molecules; apoptosis inhibiting agents; Visudyne..TM..,
snET2 and other photo sensitizers, which may be used with
photodynamic therapy (PDT); inhibitors of hepatocyte growth factor
(antibodies to the growth factor or its receptors, small molecular
inhibitors of the c-met tyrosine kinase, truncated versions of HGF
e.g. NK4).
[0306] The therapeutic agent 110 may comprise a combination with
other therapeutic agents and therapies, including but not limited
to agents and therapies useful for the treatment of angiogenesis or
neovascularization, particularly CNV. Non-limiting examples of such
additional agents and therapies include pyrrolidine,
dithiocarbamate (NF.kappa.B inhibitor); squalamine; TPN 470
analogue and fumagillin; PKC (protein kinase C) inhibitors; Tie-1
and Tie-2 kinase inhibitors; inhibitors of VEGF receptor kinase;
proteosome inhibitors such as Velcade..TM.. (bortezomib, for
injection; ranibuzumab (Lucentis..TM..) and other antibodies
directed to the same target; pegaptanib (Macugen..TM..);
vitronectin receptor antagonists, such as cyclic peptide
antagonists of vitronectin receptor-type integrins;
.alpha.-v/.beta.-3 integrin antagonists; .alpha.-v/.beta.-1
integrin antagonists; thiazolidinediones such as rosiglitazone or
troglitazone; interferon, including .gamma.-interferon or
interferon targeted to CNV by use of dextran and metal
coordination; pigment epithelium derived factor (PEDF); endostatin;
angiostatin; tumistatin; canstatin; anecortave acetate; acetonide;
triamcinolone; tetrathiomolybdate; RNA silencing or RNA
interference (RNAi) of angiogenic factors, including ribozymes that
target VEGF expression; Accutane..TM.. (13-cis retinoic acid); ACE
inhibitors, including but not limited to quinopril, captopril, and
perindozril; inhibitors of mTOR (mammalian target of rapamycin);
3-aminothalidomide; pentoxifylline; 2-methoxyestradiol;
colchicines; AMG-1470; cyclooxygenase inhibitors such as nepafenac,
rofecoxib, diclofenac, rofecoxib, NS398, celecoxib, vioxx, and
(E)-2-alkyl-2(4-methanesulfonylphenyl)-1-phenylethene; t-RNA
synthase modulator; metalloprotease 13 inhibitor;
acetylcholinesterase inhibitor; potassium channel blockers;
endorepellin; purine analog of 6-thioguanine; cyclic peroxide
ANO-2; (recombinant) arginine deiminase;
epigallocatechin-3-gallate; cerivastatin; analogues of suramin;
VEGF trap molecules; inhibitors of hepatocyte growth factor
(antibodies to the growth factor or its receptors, small molecular
inhibitors of the c-met tyrosine kinase, truncated versions of HGF
e.g. NK4); apoptosis inhibiting agents; Visudyne..TM.., snET2 and
other photo sensitizers with photodynamic therapy (PDT); and laser
photocoagulation.
[0307] The therapeutic agents may be used in conjunction with a
pharmaceutically acceptable carrier such as, for example, solids
such as starch, gelatin, sugars, natural gums such as acacia,
sodium alginate and carboxymethyl cellulose; polymers such as
silicone rubber; liquids such as sterile water, saline, dextrose,
dextrose in water or saline; condensation products of castor oil
and ethylene oxide, liquid glyceryl triester of a lower molecular
weight fatty acid; lower alkanols; oils such as corn oil, peanut
oil, sesame oil, castor oil, and the like, with emulsifiers such as
mono- or di-glyceride of a fatty acid, or a phosphatide such as
lecithin, polysorbate 80, and the like; glycols and polyalkylene
glycols; aqueous media in the presence of a suspending agent, for
example, sodium carboxymethylcellulose, sodium hyaluronate, sodium
alginate, poly(vinyl pyrrolidone) and similar compounds, either
alone, or with suitable dispensing agents such as lecithin,
polyoxyethylene stearate and the like. The carrier may also contain
adjuvants such as preserving, stabilizing, wetting, emulsifying
agents or other related materials.
[0308] The therapeutic device may comprise a container configured
to hold at least one therapeutic agent, the container comprising a
chamber to hold the at least one therapeutic agent with at least
one opening to release the at least one therapeutic agent to the
vitreous humor and porous structure 150 placed within the at least
one opening. The porous structure 150 may comprise a fixed
tortuous, porous material such as a sintered metal, a sintered
glass or a sintered polymer with a defined porosity and tortuosity
that controls the rate of delivery of the at least one therapeutic
agent to the vitreous humor. The rigid porous structures provide
certain advantages over capillary tubes, erodible polymers and
membranes as a mechanism for controlling the release of a
therapeutic agent or agents from the therapeutic device. These
advantages include the ability of the rigid porous structure to
comprise a needle stop, simpler and more cost effective
manufacture, flushability for cleaning or declogging either prior
to or after implantation, high efficiency depth filtration of
microorganisms provided by the labyrinths of irregular paths within
the structure and greater robustness due to greater hardness and
thickness of the structure compared to a membrane or erodible
polymer matrix. Additionally, when the rigid porous structure is
manufactured from a sintered metal, ceramic, glass or certain
plastics, it can be subjected to sterilization and cleaning
procedures, such as heat or radiation based sterilization and
depyrogenation, that might damage polymer and other membranes. In
certain embodiments, as illustrated in example 9, the rigid porous
structure may be configured to provide a therapeutically effective,
concentration of the therapeutic agent in the vitreous for at least
6 months. This release profile provided by certain configurations
of the rigid porous structures enables a smaller device which is
preferred in a small organ such as the eye where larger devices may
alter or impair vision.
[0309] FIG. 6A1 shows a therapeutic device 100 comprising a
container 130 having a penetrable barrier 184 disposed on a first
end, a porous structure 150 disposed on a second end to release
therapeutic agent for an extended period, and a retention structure
120 comprising an extension protruding outward from the container
to couple to the sclera and the conjunctiva. The extending
protrusion of the retention structure may comprise a diameter 120D.
The retention structure may comprise an indentation 120I sized to
receive the sclera. The container may comprise a tubular barrier
160 that defines at least a portion of the reservoir, and the
container may comprise a width, for example a diameter 134. The
diameter 134 can be sized within a range, for example within a
range from about 0.5 to about 4 mm, for example within a range from
about 1 to 3 mm and can be about 2 mm, for example. The container
may comprise a length 136, sized so as to extend from the
conjunctive to the vitreous to release the therapeutic agent into
the vitreous. The length 136 can be sized within a range, for
example within a range from about 2 to about 14 mm, for example
within a range from about 4 to 10 mm and can be about 7 mm, for
example. The volume of the reservoir may be substantially
determined by an inner cross sectional area of the tubular
structure and distance from the porous structure to the penetrable
barrier. The retention structure may comprise an annular extension
having a retention structure diameter greater than a diameter of
the container. The retention structure may comprise an indentation
configured to receive the sclera when the extension extends between
the sclera and the conjunctive. The penetrable barrier may comprise
a septum disposed on a proximal end of the container, in which the
septum comprises a barrier that can be penetrated with a sharp
object such as a needle for injection of the therapeutic agent. The
porous structure may comprise a cross sectional area 150A sized to
release the therapeutic agent for the extended period.
[0310] The porous structure 150 may comprise a first side coupled
to the reservoir 150 S1 and a second side to couple to the vitreous
150S2. The first side may comprise a first area 150A1 and the
second side may comprise a second area 150A2. The porous structure
may comprise a thickness 105T. The porous structure many comprise a
diameter 150D.
[0311] The volume of the reservoir 140 may comprise from about 5 uL
to about 2000 uL of therapeutic agent, or for example from about 10
uL to about 200 uL of therapeutic agent.
[0312] The therapeutic agent stored in the reservoir of the
container comprises at least one of a solid comprising the
therapeutic agent, a solution comprising the therapeutic agent, a
suspension comprising the therapeutic agent, particles comprising
the therapeutic agent adsorbed thereon, or particles reversibly
bound to the therapeutic agent. For example, reservoir may comprise
a suspension of a cortico-steroid such as triamcinolone acetonide
to treat inflammation of the retina. The reservoir may comprise a
buffer and a suspension of a therapeutic agent comprising
solubility within a range from about 1 ug/mL to about 100 ug/mL,
such as from about 1 ug/mL to about 40 ug/mL. For example, the
therapeutic agent may comprise a suspension of triamcinolone
acetonide having a solubility of approximately 19 ug/mL in the
buffer at 37.degree. C. when implanted.
[0313] The release rate index may comprise many values, and the
release rate index with the suspension may be somewhat higher than
for a solution in many embodiments, for example. The release rate
index may be no more than about 5, and can be no more than about
2.0, for example no more than about 1.5, and in many embodiments
may be no more than about 1.2, so as to release the therapeutic
agent with therapeutic amounts for the extended time.
[0314] The therapeutic device, including for example, the retention
structure and the porous structure, may be sized to pass through a
lumen of a catheter.
[0315] The porous structure may comprise a needle stop that limits
penetration of the needle. The porous structure may comprise a
plurality of channels configured for the extended release of the
therapeutic agent. The porous structure may comprise a rigid
sintered material having characteristics suitable for the sustained
release of the material.
[0316] FIG. 6A2 shows a therapeutic device as in FIG. 6A comprising
a rounded distal end.
[0317] FIG. 6B shows a rigid porous structure as in FIG. 6A. The
rigid porous structure 158 comprises a plurality of interconnecting
channels 156. The porous structure comprises a sintered material
composed of interconnected grains 155 of material. The
interconnected grains of material define channels that extend
through the porous material to release the therapeutic agent. The
channels may extend around the sintered grains of material, such
that the channels comprise interconnecting channels extending
through the porous material.
[0318] The rigid porous structure can be configured for injection
of the therapeutic agent into the container in many ways. The
channels of the rigid porous structure may comprise substantially
fixed channels when the therapeutic agent is injected into the
reservoir with pressure. The rigid porous structure comprises a
hardness parameter within a range from about 160 Vickers to about
500 Vickers. In some embodiments the rigid porous structure is
formed from sintered stainless steel and comprises a hardness
parameter within a range from about 200 Vickers to about 240
Vickers. In some embodiments it is preferred to inhibit ejection of
the therapeutic agent through the porous structure during filling
or refilling the reservoir of the therapeutic device with a fluid.
In these embodiments the channels of the rigid porous structure
comprise a resistance to flow of an injected solution or suspension
through a thirty gauge needle such that ejection of said solution
or suspension through the rigid porous structure is substantially
inhibited when said solution or suspension is injected into the
reservoir of the therapeutic device. Additionally, these
embodiments may optionally comprise an evacuation vent or an
evacuation reservoir under vacuum or both to facilitate filling or
refilling of the reservoir.
[0319] The reservoir and the porous structure can be configured to
release therapeutic amounts of the therapeutic agent in many ways.
The reservoir and the porous structure can be configured to release
therapeutic amounts of the therapeutic agent corresponding to a
concentration of at least about 0.1 ug per ml of vitreous humor for
an extended period of at least about three months. The reservoir
and the porous structure can be configured to release therapeutic
amounts of the therapeutic agent corresponding to a concentration
of at least about 0.1 ug per ml of vitreous humor and no more than
about 10 ug per ml for an extended period of at least about three
months. The therapeutic agent may comprise at least a fragment of
an antibody and a molecular weight of at least about 10 k Daltons.
For example, the therapeutic agent may comprise one or more of
ranibizumab or bevacizumab. Alternatively or in combination, the
therapeutic agent may comprise a small molecule drug suitable for
sustained release. The reservoir and the porous structure may be
configured to release therapeutic amounts of the therapeutic agent
corresponding to a concentration of at least about 0.1 ug per ml of
vitreous humor and no more than about 10 ug per ml for an extended
period of at least about 3 months or at least about 6 months. The
reservoir and the porous structure can be configured to release
therapeutic amounts of the therapeutic agent corresponding to a
concentration of at least about 0.1 ug per ml of vitreous humor and
no more than about 10 ug per ml for an extended period of at least
about twelve months or at least about two years or at least about
three years. The reservoir and the porous structure may also be
configured to release therapeutic amounts of the therapeutic agent
corresponding to a concentration of at least about 0.01 ug per ml
of vitreous humor and no more than about 300 ug per ml for an
extended period of at least about 3 months or 6 months or 12 months
or 24 months.
[0320] The channels of the rigid porous structure comprise a
hydrogel configured to limit a size of molecules passed through the
channels of the rigid porous structure. For example, the hydrogel
can be formed within the channels and may comprise an acrylamide
gel. The hydrogel comprises a water content of at least about 70%.
For example, the hydrogel may comprise a water content of no more
than about 90% to limit molecular weight of the therapeutic agent
to about 30k Daltons. The hydrogel comprises a water content of no
more than about 95% to limit molecular weight of the therapeutic
agent to about 100 k Daltons. The hydrogel may comprise a water
content within a range from about 90% to about 95% such that the
channels of the porous material are configured to pass Lucentis.TM.
and substantially not pass Avastin.TM..
[0321] The rigid porous structure may comprise a composite porous
material that can readily be formed in or into a wide range of
different shapes and configurations. For example, the porous
material can be a composite of a metal, aerogel or ceramic foam
(i.e., a reticulated inter-cellular structure in which the interior
cells are interconnected to provide a multiplicity of pores passing
through the volume of the structure, the walls of the cells
themselves being substantially continuous and non-porous, and the
volume of the cells relative to that of the material forming the
cell walls being such that the overall density of the intercellular
structure is less than about 30 percent theoretical density) the
through pores of which are impregnated with a sintered powder or
aerogel. The thickness, density, porosity and porous
characteristics of the final composite porous material can be
varied to conform with the desired release of the therapeutic
agent.
[0322] Embodiments comprise a method of making an integral (i.e.,
single-component) porous structure. The method may comprise
introducing particles into a mold having a desired shape for the
porous structure. The shape includes a proximal end defining a
plurality of proximal porous channel openings to couple to the
reservoir, a distal end defining a plurality of outlet channel
openings to couple to the vitreous humor of the eye, a plurality of
blind inlet cavities extending into the filter from the proximal
openings, and a plurality of blind outlet cavities extending into
the porous structure from the outlet channel openings. The method
further includes applying pressure to the mold, thereby causing the
particles to cohere and form a single component, and sintering the
component to form the porous structure. The particles can be
pressed and cohere to form the component without the use of a
polymeric binder, and the porous structure can be formed
substantially without machining.
[0323] The mold can be oriented vertically with the open other end
disposed upwardly, and metal powder having a particle size of less
than 20 micrometers can be introduced into the cavity through the
open end of the mold while vibrating the mold to achieve
substantially uniform packing of the metal powder in the cavity. A
cap can be placed on the open other end of the mold, and pressure
is applied to the mold and thereby to the metal powder in the
cavity to cause the metal powder to cohere and form a cup-shaped
powdered metal structure having a shape corresponding to the mold.
The shaped powdered metal structure can be removed from the mold,
and sintered to obtain a porous sintered metal porous
structure.
[0324] The metal porous structure can be incorporated into the
device by a press fit into an impermeable structure with an opening
configured to provide a tight fit with the porous structure. Other
means, such as welding, known to those skilled in the art can be
used to incorporate the porous structure into the device.
Alternatively, or in combination, the powdered metal structure can
be formed in a mold where a portion of the mold remains with the
shaped powdered metal structure and becomes part of the device.
This may be advantageous in achieving a good seal between the
porous structure and the device.
[0325] The release rate of therapeutic agent through a porous body,
such as a sintered porous metal structure or a porous glass
structure, may be described by diffusion of the of the therapeutic
agent within the porous structure with the channel parameter, and
with an effective diffusion coefficient equal to the diffusion
coefficient of the therapeutic agent in the liquid that fills the
reservoir multiplied by the Porosity and a Channel Parameter of the
porous body:
Release Rate=(D P/F) A (c.sub.R-c.sub.V)/L, where:
c.sub.R=Concentration in reservoir [0326] c.sub.V=Concentration
outside of the reservoir or in the vitreous [0327] D=Diffusion
coefficient of the therapeutic agent in the reservoir solution
[0328] P=Porosity of porous structure [0329] F=Channel parameter
that may correspond to a tortuosity parameter of channels of porous
structure [0330] A=Area of porous structure [0331] L=Thickness
(length) of porous structure
[0331] Cumulative Release=1-cR/cR0=1-exp((-D PA/FL V.sub.R) t),
where
t=time, Vr=reservoir volume
[0332] The release rate index can (hereinafter RRI) be used to
determine release of the therapeutic agent. The RRI may be defined
as (PA/FL), and the RRI values herein will have units of mm unless
otherwise indicated. Many of the porous structures used in the
therapeutic delivery devices described here have an RRI of no more
than about 5.0, often no more than about 2.0, and can be no more
than about 1.2 mm.
[0333] The channel parameter can correspond to an elongation of the
path of the therapeutic agent released through the porous
structure. The porous structure may comprise many interconnecting
channels, and the channel parameter can correspond to an effective
length that the therapeutic agent travels along the interconnecting
channels of the porous structure from the reservoir side to the
vitreous side when released. The channel parameter multiplied by
the thickness (length) of the porous structure can determine the
effective length that the therapeutic agent travels along the
interconnecting channels from the reservoir side to the vitreous
side. For example, the channel parameter (F) of about 1.5
corresponds to interconnecting channels that provide an effective
increase in length traveled by the therapeutic agent of about 50%,
and for a 1 mm thick porous structure the effective length that the
therapeutic agent travels along the interconnecting channels from
the reservoir side to the vitreous side corresponds to about 1.5
mm. The channel parameter (F) of at least about 2 corresponds to
interconnecting channels that provide an effective increase in
length traveled by the therapeutic agent of about 100%, and for a 1
mm thick porous structure the effective length that the therapeutic
agent travels along the interconnecting channels from the reservoir
side to the vitreous side corresponds to at least about 2.0 mm. As
the porous structure comprises many interconnecting channels that
provide many alternative paths for release of the therapeutic
agent, blockage of some of the channels provides no substantial
change in the effective path length through the porous structure as
the alternative interconnecting channels are available, such that
the rate of diffusion through the porous structure and the release
of the therapeutic agent are substantially maintained when some of
the channels are blocked.
[0334] If the reservoir solution is aqueous or has a viscosity
similar to water, the value for the diffusion coefficient of the
therapeutic agent (TA) in water at the temperature of interest may
be used. The following equation can be used to estimate the
diffusion coefficient at 37.degree. C. from the measured value of
D.sub.BSA,20C=6.1 e-7 cm2/s for bovine serum albumin in water at
20.degree. C. (Molokhia et al, Exp Eye Res 2008):
D.sub.TA,37C=D.sub.BSA,20C(.eta..sub.20C/.eta..sub.37C)(MW.sub.BSA/MW.su-
b.TA).sup.1/3 where
MW refers to the molecular weight of either BSA or the test
compound and .eta. is the viscosity of water. The following lists
diffusion coefficients of proteins of interest.
TABLE-US-00003 Diff Coeff Compound MW Temp C. (cm{circumflex over (
)}2/s) BSA 69,000 20 6.1E-07 BSA 69,000 37 9.1E-07 Ranibizumab
48,000 20 6.9E-07 Ranibizumab 48,000 37 1.0E-06 Bevacizumab 149,000
20 4.7E-07 Bevacizumab 149,000 37 7.1E-07
Small molecules have a diffusion coefficient similar to fluorescein
(MW=330, D=4.8 to 6 e-6 cm.sup.2/s from Stay, MS et al. Pharm Res
2003, 20(1), pp. 96-102). For example, the small molecule may
comprise a glucocorticoid such as triamcinolone acetonide having a
molecular weight of about 435.
[0335] The porous structure comprises a porosity, a thickness, a
channel parameter and a surface area configured to release
therapeutic amounts for the extended period. The porous material
may comprise a porosity corresponding to the fraction of void space
of the channels extending within the material. The porosity
comprises a value within a range from about 3% to about 70%. In
other embodiments, the porosity comprises a value with a range from
about 5% to about 10% or from about 10% to about 25%, or for
example from about 15% to about 20%. Porosity can be determined
from the weight and macroscopic volume or can be measured via
nitrogen gas adsorption
[0336] The porous structure may comprise a plurality of porous
structures, and the area used in the above equation may comprise
the combined area of the plurality of porous structures.
[0337] The channel parameter may comprise a fit parameter
corresponding to the tortuosity of the channels. For a known
porosity, surface area and thickness of the surface parameter, the
curve fit parameter F, which may correspond to tortuosity of the
channels can be determined based on experimental measurements. The
parameter PA/FL can be used to determine the desired sustained
release profile, and the values of P, A, F and L determined. The
rate of release of the therapeutic agent corresponds to a ratio of
the porosity to the channel parameter, and the ratio of the
porosity to the channel parameter can be less than about 0.5 such
that the porous structure releases the therapeutic agent for the
extended period. For example, the ratio of the porosity to the
channel parameter is less than about 0.1 or for example less than
about 0.2 such that the porous structure releases the therapeutic
agent for the extended period. The channel parameter may comprise a
value of at least about 1, such as at least about 1.2. For example,
the value of the channel parameter may comprise at least about 1.5,
for example at least about 2, and may comprise at least about 5.
The channel parameter can be within a range from about 1.1 to about
10, for example within a range from about 1.2 to about 5. A person
of ordinary skill in the art can conduct experiments based on the
teachings described herein to determine empirically the channel
parameter to release the therapeutic agent for an intended release
rate profile.
[0338] The area in the model originates from the description of
mass transported in units of flux; i.e., rate of mass transfer per
unit area. For simple geometries, such as a porous disc mounted in
an impermeable sleeve of equal thickness, the area corresponds to
one face of the disc and the thickness, L, is the thickness of the
disc. For more complex geometries, such as a porous body in the
shape of a truncated cone, the effective area is a value in between
the area where therapeutic agent enters the porous body and the
area where therapeutic agent exits the porous body.
[0339] A model can be derived to describe the release rate as a
function of time by relating the change of concentration in the
reservoir to the release rate described above. This model assumes a
solution of therapeutic agent where the concentration in the
reservoir is uniform. In addition, the concentration in the
receiving fluid or vitreous is considered negligible (c.sub.V=0).
Solving the differential equation and rearrangement yields the
following equations describing the concentration in the reservoir
as a function of time, t, and volume of the reservoir, V.sub.R, for
release of a therapeutic agent from a solution in a reservoir
though a porous structure.
c.sub.R=c.sub.R0 exp((-D PA/FL V.sub.R)t)
and Cumulative Release=1-c.sub.R/c.sub.R0
[0340] When the reservoir contains a suspension, the concentration
in reservoir, c.sub.R, is the dissolved concentration in
equilibrium with the solid (i.e., the solubility of the therapeutic
agent). In this case, the concentration in the reservoir is
constant with time, the release rate is zero order, and the
cumulative release increases linearly with time until the time when
the solid is exhausted.
[0341] Therapeutic concentrations for many ophthalmic therapeutic
agents may be determined experimentally by measuring concentrations
in the vitreous humor that elicit a therapeutic effect. Therefore,
there is value in extending predictions of release rates to
predictions of concentrations in the vitreous. A one-compartment
model may be used to describe elimination of therapeutic agent from
eye tissue.
[0342] Current intravitreal administration of therapeutic agents
such as Lucentis.TM. involves a bolus injection. A bolus injection
into the vitreous may be modeled as a single exponential with rate
constant, k=0.693/half-life and a cmax=dose/V.sub.v where V.sub.v
is the vitreous volume. As an example, the half-life for
ranibizumab is approximately 3 days in the rabbit and the monkey
(Gaudreault et al.) and 9 days in humans (Lucentis.TM. package
insert). The vitreous volume is approximately 1.5 mL for the rabbit
and monkey and 4.5 mL for the human eye. The model predicts an
initial concentration of 333 ug/mL for a bolus injection of 0.5 mg
Lucentis.TM. into the eye of a monkey. This concentration decays to
a vitreous concentration of 0.1 ug/mL after about a month.
[0343] For devices with extended release, the concentration in the
vitreous changes slowly with time. In this situation, a model can
be derived from a mass balance equating the release rate from the
device (described by equations above) with the elimination rate
from the eye, k c.sub.v V.sub.v. Rearrangement yields the following
equation for the concentration in the vitreous: c.sub.v=Release
rate from device/k V.sub.v.
[0344] Since the release rate from a device with a solution of
therapeutic agent decreases exponentially with time, the
concentration in the vitreous decreases exponentially with the same
rate constant. In other words, vitreous concentration decreases
with a rate constant equal to D PA/FL V.sub.R and, hence, is
dependent on the properties of the porous structure and the volume
of the reservoir.
[0345] Since the release rate is zero order from a device with a
suspension of therapeutic agent, the vitreous concentration will
also be time-independent. The release rate will depend on the
properties of the porous structure via the ratio, PA/FL , but will
be independent of the volume of the reservoir until the time at
which the drug is exhausted.
[0346] The channels of the rigid porous structure can be sized in
many ways to release the intended therapeutic agent. For example,
the channels of the rigid porous structure can be sized to pass
therapeutic agent comprising molecules having a molecular weight of
at least about 100 Daltons or for example, at least about 50 k
Daltons. The channels of the rigid porous structure can be sized to
pass therapeutic agent comprising molecules comprising a
cross-sectional size of no more than about 10 nm. The channels of
the rigid porous structure comprise interconnecting channels
configured to pass the therapeutic agent among the interconnecting
channels. The rigid porous structure comprises grains of rigid
material and wherein the interconnecting channels extend at least
partially around the grains of rigid material to pass the
therapeutic agent through the porous material. The grains of rigid
material can be coupled together at a loci of attachment and
wherein the interconnecting channels extend at least partially
around the loci of attachment.
[0347] The porous structure and reservoir may be configured to
release the glucocorticoid for an extended time of at least about
six months with a therapeutic amount of glucocorticoid of
corresponding to an in situ concentration within a range from about
0.05 ug/mL to about 4 ug/mL, for example from 0.1 ug/mL to about 4
ug/mL, so as to suppress inflammation in the retina-choroid.
[0348] The porous structure comprises a sintered material. The
sintered material may comprise grains of material in which the
grains comprise an average size of no more than about 20 um. For
example, the sintered material may comprise grains of material in
which the grains comprise an average size of no more than about 10
um, an average size of no more than about 5 um, or an average size
of no more than about 1 um. The channels are sized to pass
therapeutic quantities of the therapeutic agent through the
sintered material for the extended time based on the grain size of
the sintered material and processing parameters such as compaction
force and time and temperature in the furnace. The channels can be
sized to inhibit penetration of microbes including bacteria and
fungal spores through the sintered material.
[0349] The sintered material comprises a wettable material to
inhibit bubbles within the channels of the material.
[0350] The sintered material comprises at least one of a metal, a
ceramic, a glass or a plastic. The sintered material may comprises
a sintered composite material, and the composite material comprises
two or more of the metal, the ceramic, the glass or the plastic.
The metal comprises at least one of Ni, Ti, nitinol, stainless
steel including alloys such as 304, 304L, 316 or 316L, cobalt
chrome, elgiloy, hastealloy, c-276 alloy or Nickel 200 alloy. The
sintered material may comprise a ceramic. The sintered material may
comprise a glass. The plastic may comprise a wettable coating to
inhibit bubble formation in the channels, and the plastic may
comprise at least one of polyether ether ketone (PEEK),
polyethylene, polypropylene, polyimide, polystyrene, polycarbonate,
polyacrylate, polymethacrylate, or polyamide.
[0351] The rigid porous structure may comprise a plurality of rigid
porous structures coupled to the reservoir and configured to
release the therapeutic agent for the extended period. For example,
additional rigid porous structure can be disposed along the
container, for example the end of the container may comprise the
porous structure, and an additional porous structure can be
disposed along a distal portion of the container, for example along
a tubular sidewall of the container.
[0352] The therapeutic device can be tuned to release therapeutic
amounts of the therapeutic agent above the minimum inhibitory
concentration for an extended time based on bolus injections of the
therapeutic agent. For example, the volume of the chamber of the
reservoir can be sized with the release rate of the porous
structure based on the volume of the bolus injection. A formulation
of a therapeutic agent can be provided, for example a known
intravitreal injection formulation. The therapeutic agent can be
capable of treating the eye with bolus injections, such that the
formulation has a corresponding period between each of the bolus
injections to treat the eye. For example the bolus injections may
comprise monthly injections. Each of the bolus injections comprises
a volume of the formulation, for example 50 uL. Each of the bolus
injections of the therapeutic agent may correspond to a range of
therapeutic concentrations of the therapeutic agent within the
vitreous humor over the time course between injections, and the
device can be tuned so as to release therapeutic amounts of the
therapeutic agent such that the vitreous concentrations of the
released therapeutic agent from the device are within the range of
therapeutic concentrations of the corresponding bolus injections.
For example, the therapeutic agent may comprise a minimum
inhibitory concentration to treat the eye, for example at least
about 3 ug/mL, and the values of the range of therapeutic
concentrations can be at least about 3 ug/mL. The therapeutic
device can be configured to treat the eye with an injection of the
monthly volume of the formulation into the device, for example
through the penetrable barrier. The reservoir of the container has
a chamber to contain a volume of the therapeutic agent, for example
35 uL, and a mechanism to release the therapeutic agent from the
chamber to the vitreous humor.
[0353] The volume of the container and the release mechanism can be
tuned to treat the eye with the therapeutic agent with vitreous
concentrations within the therapeutic range for an extended time
with each injection of the quantity corresponding to the bolus
injection, such that the concentration of the therapeutic agent
within the vitreous humor remains within the range of therapeutic
concentrations and comprises at least the minimum inhibitory
concentration. The extended time may comprise at least about twice
the corresponding period of the bolus injections. The release
mechanism comprises one or more of a porous frit, a sintered porous
frit, a permeable membrane, a semi-permeable membrane, a capillary
tube or a tortuous channel, nano-structures, nano-channels or
sintered nano-particles. For example, the porous frit may comprises
a porosity, cross sectional area, and a thickness to release the
therapeutic agent for the extended time. The volume of the
container reservoir can be sized in many ways in relation to the
volume of the injected formulation and can be larger than the
volume of injected formulation, smaller than the volume of injected
formulation, or substantially the same as the volume of injected
formulation. For example, the volume of the container may comprise
no more than the volume of the formulation, such that at least a
portion of the formulation injected into the reservoir passes
through the reservoir and comprises a bolus injection to treat the
patient immediately. As the volume of the reservoir is increased,
the amount of formulation released to the eye through the porous
structure upon injection can decrease along with the concentration
of active ingredient of the therapeutic agent within the reservoir,
and the release rate index can be increased appropriately so as to
provide therapeutic amounts of therapeutic agent for the extended
time. For example, the volume of the reservoir of the container can
be greater than the volume corresponding to the bolus injection, so
as to provide therapeutic amounts for at least about five months,
for example 6 months, with an injection volume corresponding to a
monthly injection of Lucentis.TM.. For example, the formulation may
comprise commercially available Lucentis.TM., 50 uL, and the
reservoir may comprise a volume of about 100 uL and provide
therapeutic vitreous concentrations of at least about 3 ug/mL for
six months with 50 uL of Lucentis.TM. injected into the
reservoir.
[0354] The chamber may comprise a substantially fixed volume and
the release rate mechanism comprises a substantially rigid
structure to maintain release of the therapeutic agent above the
minimum inhibitory concentration for the extended time with each
injection of a plurality of injections.
[0355] A first portion of the injection may pass through the
release mechanism and treat the patient when the formulation is
injected, and a second portion of the formulation can be contained
in the chamber when the formulation is injected.
[0356] FIG. 6B-1 shows interconnecting channels 156 extending from
first side 150S1 to second side 150S2 of the porous structure as in
FIG. 6B. The interconnecting channels 156 extend to a first opening
158A1, a second opening 158A2 and an Nth opening 158AN on the first
side 150S1. The interconnecting channels 156 extend to a first
opening 158B1, a second opening 158B2 and an Nth opening 158BN on
the second side 150S2. Each of the openings of the plurality of
channels on the first side is connected to each of the openings of
plurality of channels on the second side, such that effective
length traveled along the channels is greater than thickness 150T.
The channel parameter can be within a range from about 1.1 to about
10, such that the effective length is within a range from about 1.1
to 10 times the thickness 150T. For example, the channel parameter
can be about 1 and the porosity about 0.2, such that the effective
length corresponds to at least about 5 times the thickness
150T.
[0357] FIG. 6B-2 shows a plurality of paths of the therapeutic
agent along the interconnecting channels extending from a first
side 150S1 to a second side 150S2 of the porous structure as in
FIGS. 6B and 6B-1. The plurality of paths comprises a first path
156P1 extending from the first side to the second side, a second
path 156P2 extending from the first side to the second side and a
third path 156P3 extending from the first side to the second side,
and many additional paths. The effect length of each of first path
P1, second path P2 and third path P3 is substantially similar, such
that each opening on the first side can release the therapeutic
agent to each interconnected opening on the second side. The
substantially similar path length can be related to the sintered
grains of material and the channels that extend around the sintered
material. The porous structure may comprise randomly oriented and
connected grains of material, packed beads of material, or
combinations thereof. The channel parameter can be related to the
structure of the sintered grains of material and corresponding
interconnecting channels, porosity of the material, and percolation
threshold. Work in relation to embodiments shows that the
percolation threshold of the sintered grains may be below the
porosity of the porous frit structure, such that the channels are
highly inter-connected. The sintered grains of material can provide
interconnected channels, and the grains can be selected to provide
desired porosity and channel parameters and RRI as described
herein.
[0358] The channel parameter and effective length from the first
side to the second side can be configured in many ways. The channel
parameter can be greater than 1 and within a range from about 1.2
to about 5.0, such that the effective length is within a range
about 1.2 to 5.0 times the thickness 150T, although the channel
parameter may be greater than 5, for example within a range from
about 1.2 to 10. For example, the channel parameter can be from
about 1.3 to about 2.0, such that the effective length is about 1.3
to 2.0 times the thickness 150T. For example, experimental testing
has shown the channel parameter can be from about 1.4 to about 1.8,
such that the effective length is about 1.4 to 1.8 times the
thickness 150T, for example about 1.6 times the thickness. These
values correspond to the paths of the channels around the sintered
grains of material, and may correspond, for example, to the paths
of channels around packed beads of material.
[0359] FIG. 6B-3 shows blockage of the openings with a covering
156B and the plurality of paths of the therapeutic agent along the
interconnecting channels extending from a first side to a second
side of the porous structure as in FIGS. 6B and 6B-1. A plurality
of paths 156PR extend from the first side to the second side couple
the first side to the second side where one of the sides is
covered, such that the flow rate is maintained when one of the
sides is partially covered.
[0360] FIG. 6B-4 shows blockage of the openings with particles
156PB and the plurality of paths of the therapeutic agent along the
interconnecting channels extending from a first side to a second
side of the porous structure as in FIGS. 6B and 6B-1. The plurality
of paths 156PR extend from the first side to the second side couple
the first side to the second side where one of the sides is
covered, such that the flow rate is maintained when one of the
sides is partially covered
[0361] FIG. 6B-5 shows an effective cross-sectional size 150DE and
area 150EFF corresponding to the plurality of paths of the
therapeutic agent along the interconnecting channels extending from
a first side to a second side of the porous structure as in FIGS.
6B and 6B-1. The effective cross sectional area of the
interconnecting channels corresponds to the internal
cross-sectional area of the porous structure disposed between the
openings of the first side and the openings of the second side,
such that the rate of release can be substantially maintained when
the channels are blocked on the first side and the second side.
[0362] The rigid porous structure can be shaped and molded in many
ways for example with tubular shapes, conical shapes, discs and
hemispherical shapes. The rigid porous structure may comprise a
molded rigid porous structure. The molded rigid porous structure
may comprises at least one of a disk, a helix or a tube coupled to
the reservoir and configured to release the therapeutic agent for
the extended period.
[0363] FIG. 6C shows a rigid porous structure as in FIG. 6B
incorporated into a scleral tack 601 as described in U.S. Pat. No.
5,466,233. The scleral tack comprises a head 602, a central portion
603 and a post 604. The post may comprise the reservoir 605 and the
rigid porous structure 606 as described above. The porous structure
may comprise a molded conical structure having a sharp tip
configured for insertion into the patient. Alternatively or in
combination, the tip may be rounded.
[0364] FIG. 6E, shows a plurality of rigid porous structures as in
FIG. 6B incorporated with a drug delivery device for sustained
release as described in U.S. Pat. No. 5,972,369. The therapeutic
device comprises a reservoir 613 to contain the therapeutic agent
and an impermeable and non-porous outer surface 614. The reservoir
is coupled to a rigid porous structure 615 that extends to a distal
end 617. The rigid porous structure comprises an exposed area 616
on the distal end to release the therapeutic agent, and the
impermeable and non-porous outer surface may extend to the distal
end.
[0365] FIG. 6D shows a rigid porous structure as in FIG. 6B
incorporated with a delivery device for sustained release as
described in U.S. Pat. Pub. 2003/0014036 A1. The drug delivery
device comprises an inlet port 608 on the proximal end and a hollow
body 609 coupled to the inlet port. The hollow body comprises many
openings 612 that allow a solution injected into the inlet port to
pass from the hollow body into a balloon 610. The balloon comprises
a distal end 611 disposed opposite the injection port. The balloon
comprises a plurality of the rigid porous structures 607, as
described above. Each of the plurality of porous rigid structures
comprises a first surface exposed to the interior of the balloon
and a second surface configured to contact the vitreous. The
calculated area can be the combined area of the plurality of porous
rigid structures as noted above.
[0366] FIG. 6F shows a rigid porous structure as in FIG. 6B
incorporated with a non-linear body member 618 for sustained
release as described in U.S. Pat. No. 6,719,750. The non-linear
member may comprise a helical shape. The non-linear member can be
coupled to a cap 619 on the proximal end 620. The non-linear member
may comprise a lumen 621 filled with therapeutic agent so as to
comprise a reservoir 622. The porous structure 623 can be disposed
on a distal end 624 of the non-linear member to release the
therapeutic agent. The porous structure may be located at
additional or alternative locations of the non-linear member. For
example a plurality of porous structures may be disposed along the
non-linear member at locations disposed between the cap and distal
end so as to release therapeutic agent into the vitreous humor when
the cap is positioned against the sclera.
[0367] FIG. 6G shows porous nanostructures, in accordance with
embodiments. The porous structure 150 may comprise a plurality of
elongate nano-channels 156NC extending from a first side 150S1 of
the porous structure to a second side 150S2 of the porous
structure. The porous structure 150 may comprise a rigid material
having the holes formed thereon, and the holes may comprise a
maximum dimension across such as a diameter. The diameter of the
nano-channels may comprise a dimension across, for example from
about 10 nm across, to about 1000 nm across, or larger. The
channels may be formed with etching of the material, for example
lithographic etching of the material. The channels may comprise
substantially straight channels such that the channel parameter F
comprises about 1, and the parameters area A, and thickness or
length L correspond to the combined cross-sectional area of the
channels and the thickness or length of the porous structure.
[0368] The porous structure 150 may comprise interconnecting
nano-channels, for example formed with a sintered nano-material.
The sintered nanomaterial may comprise nanoparticles sintered so as
to form a plurality of interconnecting channels as described
herein, and can be made of a suitable size so as to provide an RRI
as described herein. For example, the porous structure 150
comprising interconnecting nano-channels may comprise a decreased
cross sectional area so as to provide a low RRI as described
herein, such as an RRI of about 0.001 or more, for example an RRI
of 0.002. The area can be increased and thickness decreased of the
porous structure 150 comprising interconnecting channels so as to
provide an increased RRI, for example of about 5. The RRI of the
porous structure 150 comprising the plurality of interconnecting
channels may comprise a value within a range from about 0.001 to
about 5, for example from about 0.002 to about 5, for example a
sintered porous material based on the teachings described
herein.
[0369] The injection of therapeutic agent into the device 100 as
described herein can be performed before implantation into the eye
or alternatively when the therapeutic device is implanted into the
eye.
[0370] FIG. 7 shows a therapeutic device 100 coupled to an injector
701 that removes material from the device and injects therapeutic
agent 702 into the device. The injector picks up spent media 703
and refills the injector with fresh therapeutic agent. The
therapeutic agent is injected into the therapeutic device. The
spent media is pulled up into the injector. The injector may
comprise a stopper mechanism 704.
[0371] The injector 701 may comprise a first container 702C to
contain a formulation of therapeutic agent 702 and a second
container 703C to receive the spent media 703. Work in relation to
embodiments suggests that the removal of spent media 703 comprising
material from the container reservoir of the therapeutic device can
remove particulate from the therapeutic device, for example
particles comprised of aggregated therapeutic agent such as
protein. The needle 189 may comprise a double lumen needle with a
first lumen coupled to the first container and a second lumen
coupled to the second container, such that spent media 703 passes
from the container reservoir of device 100 to the injector. A valve
703V, for example a vent, can be disposed between the second lumen
and the second container. When the valve is open and therapeutic
agent is injected, spent media 703 from the container reservoir of
the therapeutic device 100 passes to the second container of the
injector, such that at least a portion of the spent media within
the therapeutic device is exchanged with the formulation. When the
valve is closed and the therapeutic agent is injected, a portion of
the therapeutic agent passes from the reservoir of the therapeutic
device into the eye. For example, a first portion of formulation of
therapeutic agent can be injected into therapeutic device 100 when
the valve is open such that the first portion of the formulation is
exchanged with material disposed within the reservoir; the valve is
then closed and a second portion of the formulation is injected
into therapeutic device 100 such that at least a portion of the
first portion passes through the porous structure into the eye.
Alternatively or in combination, a portion of the second portion of
injected formulation may pass through the porous structure when the
second portion is injected into the eye. The second portion of
formulation injected when the valve is closed may correspond to a
volume of formulation that passes through the porous structure into
the vitreous humor to treat the patient immediately.
[0372] The needle 189 may comprise a dual lumen needle, for example
as described with reference to FIG. 7A2 shown below.
[0373] FIG. 7A shows a therapeutic device 100 coupled to an
injector 701 to inject and remove material from the device. The
injector may comprise a two needle system configured to insert into
a container of the device. The injector may simultaneously inject
therapeutic agent through the first needle 705 (the injection
needle) while withdrawing liquid from the device through the second
needle 706 (the vent needle). The injection needle may be longer
and/or have a smaller diameter than the vent needle to facilitate
removal of prior material from the device. The vent needle may also
be attached to a vacuum to facilitate removal of prior material
from the device.
[0374] FIG. 7A-1 shows a therapeutic device 100 comprising a
penetrable barrier coupled to an injector needle 189 comprising a
stop 189S that positions the distal end of the needle near the
proximal end of the reservoir 130 of the device to flush the
reservoir with ejection of liquid formulation through the porous
frit structure, in accordance with embodiments. For example, the
injector needle may comprise a single lumen needle having a bevel
that extends approximately 0.5 mm along the shaft of the needle
from the tip of the needle to the annular portion of the needle.
The stop can be sized and positioned along an axis of the needle
such that the needle tip extends a stop distance 189SD into the
reservoir as defined by the length of the needle from the stop to
the tip and the thickness of the penetrable barrier, in which the
stop distance is within a range from about 0.5 to about 2 mm. The
reservoir may extend along an axis of the therapeutic device
distance within a range from about 4 to 8 mm. A volume comprising a
quantity of liquid formulation within a range from about 20 to
about 200 uL, for example about 50 uL can be injected into the
therapeutic device with the needle tip disposed on the distal end.
The volume of the reservoir can be less than the injection volume
of the formulation of therapeutic agent, such that liquid is
flushed through the porous structure 150. For example, the
reservoir may comprise a volume within a range from about 20 to 40
uL, and the injection volume of the liquid formulation of
therapeutic agent may comprise about 40 to 100 uL, for example
about 50 uL.
[0375] FIG. 7A-2 shows a therapeutic device comprising a penetrable
barrier coupled to a needle 189 of an injector 701 to inject and
remove material from the device such that the liquid in the
reservoir 130 is exchanged with the injected formulation. The
needle comprises at least one lumen and may comprise a concentric
double lumen needle 189DL with a distal end coupled to the inner
lumen to inject formulation of the therapeutic agent into the
therapeutic device and a proximal vent 189V to receive liquid into
the needle when the formulation is injected. Alternatively, the
vent may correspond to an opening on the distal end of the inner
lumen of the needle and the outer lumen may comprise a proximal
opening to inject therapeutic agent formulation into a proximal
portion of the container reservoir.
[0376] Work in relation to the injector embodiments indicates that
a filling efficiency of at least about 80%, for example 90% or more
can be achieved with injector apparatus and needles as described
above.
[0377] The vent 189V may comprise a resistance to flow of the
injected formulation, and the porous structure 150 may comprise a
resistance to flow. The resistance to flow of the vent 189V can be
lower than the resistance to flow of the porous structure 150 so as
to inhibit release of a bolus when the therapeutic formulation is
placed in the reservoir chamber. Alternatively, the injector can
inject a bolus as described herein.
[0378] FIG. 7A-3 shows a deformable visual indicator 189DS. The
deformable visual indicator can be coupled to a support, for
example stop 189S, such that the visual indicator can deform to
indicate when the needle is positioned to an appropriate depth
189SD. The visual indicator can be used with an injector such as a
syringe and can be used for injections into one or more of many
tissues such as dental, internal tissues during surgery and ocular
tissues such as the conjunctiva of the eye. The needle 189 may
comprise a silicon needle, for example a 25 GA or more needle, for
example a 30 GA needle.
[0379] The visual indicator 189DS may comprise a bright color and
may comprise a soft deformable material such as silicone, and may
have a Shore A hardness from about 5 to about 30, for example. The
stop 189S may comprise a dark color, such that the deformable
indicator becomes visible when coupled to tissue. Prior to contact
with the tissue, the deformable indicator 189DS has a first width
189DSW1.
[0380] FIG. 7A-4 shows the visual indicator 189DS coupled to soft
tissue, such as tissue of an eye, for example the conjunctiva
positioned over the penetrable barrier of the therapeutic device
100. The visual indicator has been deformed and comprises a second
width 189DSW2 that is greater than the first width such that the
deformable indicator is visible when viewed when coupled to the
tissue surface. Such visual indication of coupling can be helpful
to ensure that the correct amount of pressure is applied by the
health care provider and also so that the needle tips is located at
an intended distance below the surface of the tissue.
[0381] FIG. 7A-5 shows a therapeutic device 100 coupled to injector
701 with one or more of potentially insufficient force prior to
injection or potentially insufficient depth. As noted above, the
therapeutic device may provide at least some resistance to flow,
and the visual indicator 189DS can indicate when operator has
applied sufficient force to counter reactive force of the
injection. Also, the percent mixing can be related to the accuracy
of the injection, for example with a bolus injection through the
therapeutic device, and placement of the needle tip at depth 189SD
with an accuracy of better than about 1 mm or less can ensure that
the mixing and/or exchange amount injections is consistent such
that the dosage of therapeutic agent can be delivered
accurately.
[0382] FIG. 7A-6 shows a therapeutic device 100 coupled to injector
701 with one or more of potentially insufficient force prior to
injection or potentially insufficient depth.
[0383] FIG. 7A-7A to FIG. 7A-9B show sliding coupling of a valve to
a plunger coupled to a piston to exchange a first intended volume
of liquid within the reservoir with a volume of formulation of
therapeutic agent and close the valve so as to inject a second
volume of liquid through the porous frit structure. FIG. 7A-7A,
FIG. 7A-8A, and FIG. 7A-9A show a first configuration with the
injector 701 coupled to a double lumen needle 189L such that a
second lumen 189B injects therapeutic agent 110 from a chamber 702C
into device 100. A second container 703C is coupled to a first
lumen 189A that extends to the chamber of the reservoir container
and receives liquid from device 100, such that liquid of device 100
is exchanged. A switching valve 703V comprises a first moving
component, for example a sliding component, and a second component
comprising an opening that can be blocked, for example covered,
with the moving component. A piston 701P is moved toward the device
100 with a plunger, and the sliding component of switching valve
703V is coupled to the plunger and piston. When the piston has
advanced to exchange an intended amount of liquid and an intended
amount of the formulation the therapeutic agent 110 remains in
chamber 702C, the sliding component of valve 703 covers and blocks
the opening component of valve 703V. With valve 703 closed, an
intended amount of therapeutic agent is injected into device 100,
for example such that a bolus amount of therapeutic agent can be
injected from device 100. A portion of the formulation of
therapeutic agent injected into device 100 can be retained in
device 100 for release for an extended time.
[0384] The moving component of the valve may comprise one or more
of many components such as a ball valve, a sleeve, a gasket, a
piston having holes, or a one way pressure valve, a solenoid, or a
servo, for example.
[0385] FIG. 7A-10A and FIG. 7A-10B show a first configuration of an
injector to maintain the rate of flow into device to within about
+/-50%, for example to within about +/-25%, such that the time to
inject the therapeutic agent into device 100 remains substantially
constant amount devices and injections. For example, as the release
rate index can be less than about 0.5, for example less than about
0.1, for example less than about 0.05, and the amount of time to
inject fully substantially fixed volume of the therapeutic device
can be inversely related to the release rate index.
[0386] The injector 701 comprises a mechanism to maintain the rate
of flow into the device and limit a maximum amount of flow, for
example with a spring. The mechanism may comprise one or more of a
mechanical mechanism, an electrical mechanism, a pneumatic
mechanism, or an hydraulic mechanism, or combinations thereof.
Although a mechanical mechanism is shown, the above described
mechanisms can provide similar results.
[0387] The visible indicator 189DS can be used to indicate to the
operator that injector is coupled to the therapeutic device
implanted in the eye at a depth for injection. The operator can
then depress the plunger.
[0388] The plunger comprises a telescopic joint and a spring, such
that the joint can be slid together such that the plunger is urged
downward to contact the stop. When the plunger is urged downward,
the spring is compressed when the ends of the telescopic joint come
together. The compressed spring urges the piston toward the
therapeutic device such that the formulation of therapeutic agent
is injected into the therapeutic device with the force of the
spring. The valve 703V can close as described above. The second
portion of the injection corresponding to the bolus injection is
injected into the therapeutic device 100 and through porous
structure 150.
[0389] FIG. 7B-1 shows a side cross-sectional view of therapeutic
device 100 comprising a retention structure having a cross-section
sized to fit in an elongate incision. The cross-section sized to
fit in the elongate incision may comprise a narrow portion 120N of
retention structure 120 that is sized smaller than the flange 122.
The narrow portion 120N sized to fit in the elongate incision may
comprise an elongate cross section 120NE sized to fit in the
incision. The narrow portion 120N may comprise a cross-section
having a first cross-sectional distance across, or first
dimensional width, and a second cross-sectional distance across, or
second dimensional width, in which the first cross-sectional
distance across is greater than the second cross-sectional distance
across such that the narrow portion 120N comprises an elongate
cross-sectional profile.
[0390] The elongate cross section 120NE of the narrow portion 120N
can be sized in many ways to fit the incision. The elongate cross
section 120NE comprises a first dimension longer than a second
dimension and may comprise one or more of many shapes such as
dilated slot, dilated slit, lentoid, oval, ovoid, or elliptical.
The dilated slit shape and dilated slot shape may correspond to the
shape sclera tissue assumes when cut and dilated. The lentoid shape
may correspond to a biconvex lens shape. The elongate cross-section
of the narrow portion may comprise a first curve along an first
axis and a second curve along a second axis different than the
first curve.
[0391] Similar to the narrow portion 120N of the retention
structure, the container reservoir may comprise a cross-sectional
profile
[0392] FIG. 7B-2 shows an isometric view of the therapeutic device
as in FIG. 7B-1.
[0393] FIG. 7B-3 shows a top view of the therapeutic device as in
FIG. 7B-1.
[0394] FIG. 7B-4 shows a side cross sectional view along the short
side of the retention structure of the therapeutic device as in
FIG. 7B-1.
[0395] FIG. 7B-5 shows a bottom view of the therapeutic device as
in FIG. 7B-1 implanted in the sclera.
[0396] FIG. 7B-5A shows a cutting tool 710 comprising a blade 714
having a width 712 corresponding to perimeter 160P of the barrier
160 and the perimeter 160NP of the narrow portion. The cutting tool
can be sized to the narrow portion 120N so as to seal the incision
with the narrow portion when the narrow portion is positioned
against the sclera. For example, the width 712 may comprise about
one half of the perimeter 160P of the barrier 160 and about one
half of the perimeter 160NP of the narrow portion 160N. For
example, the outside diameter of the tube of barrier 160 may
comprise about 3 mm such that the perimeter of 160P comprises about
6 mm, and the narrow portion perimeter 160NP may comprise about 6
mm. The width 712 of the blade 710 may comprise about 3 mm such
that the incision comprises an opening having a perimeter of about
6 mm so as to seal the incision with the narrow portion 160P.
Alternatively, perimeter 160P of barrier 160 may comprise a size
slightly larger than the incision and the perimeter of the narrow
portion.
[0397] The retention structure comprises a narrow section 120N
having a short distance 120NS and a long distance 120NL so as to
fit in an elongate incision along the pars plana of the eye. The
retention structure comprises an extension 122. The extension of
the retention structure 120E comprises a short distance across 122S
and a long distance across 122S, aligned with the short distance
122NS and long distance 122NL of the narrow portion 120N of the
retention structure 120. The narrow portion 120 may comprise an
indentation 120I sized to receive the sclera.
[0398] FIGS. 7B-6A and 7B-6B show distal cross-sectional view and a
proximal cross-sectional view, respectively, of therapeutic device
100 comprising a non-circular cross-sectional size. The porous
structure 150 can be located on a distal end portion of the
therapeutic device, and the retention structure 120 can be located
on a proximal portion of therapeutic device 100. The barrier 160
defines a size of reservoir 130. The barrier 160 and reservoir 130
may each comprise an elliptical or oval cross-sectional size, for
example. The barrier 160 comprises a first cross-sectional distance
across reservoir 130, and a second cross-sectional distance across
reservoir 130, and the first distance across may extend across a
long (major) axis of an ellipse and the second distance across may
extend across a short (minor) axis of the ellipse. This elongation
of the device along one direction can allow for increased drug in
the reservoir with a decrease interference in vision, for example,
as the major axis of the ellipse can be aligned substantially with
the circumference of the pars plana region of the eye extending
substantially around the cornea of the eye, and the minor axis of
the ellipse can be aligned radially with the eye so as to decrease
interference with vision as the short axis of the ellipse extends
toward the optical axis of the eye corresponding to the patient's
line of sight through the pupil. Although reference is made to an
elliptical or oval cross-section, many cross-sectional sizes and
shapes can be used such as rectangular with a short dimension
extending toward the pupil of the eye and the long dimension
extending along the pars plana of the eye.
[0399] The retention structure 120 may comprise structures
corresponding to structure of the cross-sectional area. For
example, the extension 122 may comprise a first distance across and
a second distance across, with the first distance across greater
than the second distance across. The extension may comprise many
shapes, such as rectangular, oval, or elliptical, and the long
distance across can correspond to the long distance of the
reservoir and barrier. The retention structure 120 may comprise the
narrow portion 120N having an indentation 120I extending around an
access port to the therapeutic device, as described above. The
indentation 120I and extension 122 may each comprise an elliptical
or oval profile with a first long (major) axis of the ellipse
extending in the first direction and a second short (minor) axis of
the ellipse extending in the second direction. The long axis can be
aligned so as to extend circumferentially along the pars plana of
the eye, and the short axis can be aligned so as to extend toward
the pupil of the eye, such that the orientation of device 100 can
be determined with visual examination by the treating
physician.
[0400] FIG. 7B-6C shows an isometric view of the therapeutic device
having a retention structure comprising a narrow portion 120N with
an elongate cross-sectional size 120NE.
[0401] FIG. 7B-6D shows a distal end view of the therapeutic device
as in FIG. 7B-6C.
[0402] FIG. 7B-6E1 shows a side view of the short distance 120NS of
the narrow portion 120N of the therapeutic device as in FIG.
7B-6C.
[0403] FIG. 7B-6E2 shows a side view of the long distance 120NL of
the narrow portion 120N of the therapeutic device 100 as in FIG.
7B-6C.
[0404] FIG. 7B-6F shows a proximal view of the therapeutic device
as in FIG. 7B-6C.
[0405] FIG. 7B-6G to FIG. 7B-6I show exploded assembly drawings for
the therapeutic device 100 as in FIGS. 7B-6C to 7B-6F. The assembly
drawings of FIGS. 7B-6G, FIG. 7B-6H and FIG. 7B-6I show isometric
and thin side profiles views, respectively, of the elongate portion
120NE of the narrow portion of the retention structure 120N. The
therapeutic device 100 has an elongate axis 100A.
[0406] The penetrable barrier 184, for example the septum, can be
inserted into the access port 180. The penetrable barrier may
comprise an elastic material sized such that the penetrable barrier
can be inserted into the access port 180. The penetrable barrier
may comprise one or more elastic materials such as siloxane or
rubber. The penetrable barrier may comprise tabs 184T to retain the
penetrable barrier in the access port. The penetrable barrier 184
may comprise a beveled upper rim 184R sized to seal the access port
180. The access port 180 of the reservoir container 130 may
comprise a beveled upper surface to engage the beveled rim and seal
the penetrable barrier against the access port 180 when the tabs
184T engage an inner annular or elongate channel of the access
port. The penetrable barrier 184 may comprise an opaque material,
for example a grey material, for example silicone, such that the
penetrable barrier can be visualized by the patient and treating
physician.
[0407] The reservoir container 130 of the device may comprise a
rigid biocompatible material that extends at least from the
retention structure to the rigid porous structure, such that the
reservoir comprises a substantially constant volume when the
therapeutic agent is released with the rigid porous structure so as
to maintain a stable release rate profile, for example when the
patient moves. Alternatively or in combination, the reservoir
container 130 may comprise an optically transmissive material such
that the reservoir container 130 can be translucent, for example
transparent, such that the chamber of reservoir 140 can be
visualized when the device is loaded with therapeutic agent outside
the patient prior to implantation, for example when injected with a
formulation of therapeutic agent prior to implantation in the
physician's office. This visualization of the reservoir 140 can be
helpful to ensure that the reservoir 140 is properly filled with
therapeutic agent by the treating physician or assistant prior to
implantation. The reservoir container may comprise one or more of
many biocompatible materials such as acrylates,
polymethylmethacrylate, siloxanes, metals, titanium stainless
steel, polycarbonate, polyetheretherketone (PEEK), polyethylene,
polyethylene terephthalate (PET), polyimide, polyamide-imide,
polypropylene, polysulfone, polyurethane, polyvinylidene fluoride
or PTFE. The biocompatible material of the reservoir container may
comprise an optically transmissive material such as one or more of
acrylate, polyacrylate, methlymethacraylate, polymethlymethacrylate
(PMMA), polyacarbonate or siloxane. The reservoir container 130 can
be machined from a piece of material, or injection molded, so as to
form the retention structure 120 comprising flange 122 and the
elongate narrow portion 120NE. The flange 122 may comprise a
translucent material such that the physician can visualize tissue
under the flange to assess the patient and to decrease appearance
of the device 100 when implanted. The reservoir container 130 may
comprise a channel extending along axis 100A from the access port
180 to porous structure 150, such that formulation injected into
device 100 can be release in accordance with the volume of the
reservoir and release rate of the porous structure 150 as described
herein. The porous structure 150 can be affixed to the distal end
of therapeutic device 100, for example with glue. Alternatively or
in combination, the distal end of the reservoir container 130 may
comprise an inner diameter sized to receive the porous structure
150, and the reservoir container 130 may comprise a stop to
position the porous structure 150 at a predetermined location on
the distal end so as to define a predetermined size of reservoir
140.
[0408] FIG. 7C-1 shows an expandable therapeutic device 790
comprising expandable barrier material 160 and support 160S in an
expanded configuration for extended release of the therapeutic
agent. The expanded configuration can store an increased amount of
therapeutic agent, for example from about 30 uL to about 100 uL.
The expandable device comprises a retention structure 120, an
expandable reservoir 140. The support 160S may comprise a resilient
material configured for compression, for example resilient metal or
thermoplastic. Alternatively, the expandable support may be bent
when expanded. The expandable device comprises the porous structure
150 disposed on a distal end, and affixed to the expandable
support. The expandable device may comprise an access port 180, for
example with a penetrable barrier 184. In the expanded
configuration, the device is substantially clear from a majority of
the optical path OP of the patient
[0409] The support 160S of the barrier 160 can provide a
substantially constant volume of the reservoir in the expanded
configuration. The substantially constant volume, for example
+/-25%, can be combined with the release rate index of the porous
structure 150 so as to tune the expanded reservoir and porous
structure to the volume of therapeutic agent to be injected into
the therapeutic device as described herein. The barrier 160 may
comprise a thin compliant material, for example a membrane, and the
support 160S can urge the barrier 160 to an expanded configuration
so as to define the reservoir chamber having the substantially
constant volume.
[0410] FIG. 7C-1A shows the distal end portion of the support 160S.
The support 160S may comprise struts that extend to an annular
flange 160SF that supports the porous structure 150 on the distal
end of device 100.
[0411] FIG. 7C-1B shows the support 160S disposed inside the
barrier 160 so as to provide the substantially constant expanded
volume of the reservoir chamber.
[0412] FIG. 7C-1C shows the support 160S disposed along the inner
surface of the barrier 160 so as to provide the substantially
constant expanded volume of the reservoir chamber. The support 160
can be bonded to the barrier 160 in many ways, for example with a
bonding agent such as glue or resin, or with thermal bonding. The
support 160S can be disposed on the outside of barrier 160.
[0413] Expandable Therapeutic Device having a Substantially
Constant Reservoir Chamber Volume Configured to Decrease
Cross-sectional Size for Removal
[0414] The therapeutic device 100 may comprise an expandable device
that can be collapsible in cross-section for removal and comprises
a substantially constant reservoir volume and substantially
constant release rate index when expanded such that the device can
be tuned to receive an amount of formulation of therapeutic agent.
The expandable device may comprise an expandable therapeutic device
comprise the retention structure to couple to the sclera, a
penetrable barrier and a flexible support coupled to a flexible
barrier. The flexible support can be expandable from a first
elongate narrow profile configuration having a first length and a
first cross-sectional size to a second wide profile configuration
having a second length and a second cross-sectional size. The
second wide profile configuration can define a chamber having a
substantially constant volume when placed in the eye, in which the
first length greater than the second length, and the first
cross-sectional size is smaller than the second cross-sectional
size. The flexible support and the flexible barrier have
sufficiently flexibility so as to increase the length from the
second length to the first length and decrease the cross-sectional
size from the second size to the first size when an elongate
structure is advanced through the penetrable barrier.
[0415] The therapeutic device may comprise expandable and
collapsible container shaped with a support structure, positioned
away from visual path so as to increase chamber reservoir volume
without inhibiting vision. The therapeutic device may comprise a
collapsible cross section for removal. The therapeutic device may
comprise a substantially fixed expanded volume, such that the
substantially fixed volume is tuned to receive injection of
therapeutic agent. The substantially fixed volume may comprise a
volume fixed to within +/-50%, for example to within +/-25%. The
therapeutic device may comprise a collapsed cross-sectional size of
1 mm or less for insertion and insertion size, but could be up to 2
mm.
[0416] The therapeutic device may comprise a volume sized to
receives injection from about 1 uL to about 100 uL (most
formulations are 50 uL injection), for example a chamber reservoir
of 100 uL in the expanded substantially fixed volume
configuration.
[0417] The Expandable support frame may include one or more of the
following: a support frame comprising wire, nitinol, thermoplastic,
etc.; coupling to a flexible barrier comprising one or more of a
balloon, sheet, membrane, or membrane define the shape of chamber
with the support and barrier; support frame can be on inside,
outside or within flexible barrier material self-expanding material
or actuated, or combinations thereof; expandable for small
insertion incision, for example when the length of the device
decreases to expand the cross-sectional size to define the chamber
having substantially constant volume, collapsible for removal
through incision, for example when the length of the device
increases to decrease cross-sectional size for removal, one or more
support configurations, braided support (elongated/thin to position
the expandable device, e.g. with mandrel). Expansion volume of
reservoir may be limited to no more than 0.2 mL, such that IOP is
not substantially increased when the device expands to the
substantially constant volume wide profile configuration.
[0418] FIG. 7C-1D shows an elongate structure of a removal
apparatus inserted into the expandable and collapsible
cross-section device to decrease the cross-sectional width of the
device. The removal apparatus may comprise a guide and coupling
structure. The coupling structure may comprise one or more of a
u-shaped flange, tines, jaws, clamps, to couple to the retention
structure. The guide may comprise one or more of a channel, loop,
hole or other structure coupled to the coupling structure to align
the elongate structure with the therapeutic device to advance the
elongate structure through the penetrable barrier and along the
axis 100A to the distal portion comprising the stop. The stop may
comprise the rigid porous structure 150 or other structure coupled
to the support 160S.
[0419] FIG. 7C-1E shows the first elongate profile configuration of
support 160S comprising first length L1 and first width W1.
[0420] FIG. 7C-1F shows the second wide profile configuration of
support 160S comprising second length L2 and second width W2.
[0421] The support 160S may comprise a first proximal annular
portion 160SA, for example a ring structure, a second distal
annular portion 160SB, for example a ring structure, and struts
160SS extending axially therebetween. The struts 160SS can extend
axially from the first proximal annular portion 160SA comprising
the first ring structure to the second ring structure. The first
proximal portion 160SA may support the penetrable barrier 184 and
be sized to receive the elongate structure. The second distal
annular portion 160B can be coupled to the rigid porous structure
150, for example with the flange, such that the elongate structure
can urge the porous structure 150 axially along axis 100A so as to
increase the length from second length L2 to first length L1 to
remove the therapeutic device.
[0422] The support 160 may comprise a flexible material, for
example a shape memory material or flexible metal or plastic, such
that the struts 160SS extending from the proximal ring structure to
the distal ring structure can be compressed when placed in the
cannula as described above and then separate to define the chamber
when passed through the cannula in to the eye so as to define the
reservoir chamber having the substantially constant volume. When
the elongate structure urges the rigid porous structure away from
the proximal end coupled to the coupling so as to increase the
length of device 790, the cross-sectional width is decreased to
remove the expandable therapeutic device 790.
[0423] FIG. 7C-2 shows the expandable therapeutic device 790 as in
FIG. 7C-1 in a narrow profile configuration suitable for use in an
injection lumen.
[0424] FIG. 7C-3 shows the expandable therapeutic device as in FIG.
7C-1 in an expanded profile configuration, suitable for retention,
for example with the sclera.
[0425] FIGS. 7C-4A and 7C-4B show an expandable retention structure
792. The expandable retention structure 792 can be used with the
expandable therapeutic device 790, or with a substantially fixed
reservoir and container device as described above. The expandable
retention structure 792 comprises many compressible or expandable
or resilient materials or combinations thereof. The expandable
retention structure 792 comprise an extension 120E that can expand
from the narrow profile configuration to the expanded
configuration, for example with tabs and flanges comprising
resilient material. The upper portion can be inclined proximally
and the distal portion can be inclined distally, such that the
retention structure expands to engage opposite sides of the sclera.
The resilient material may comprise a thermoplastic material, a
resilient metal, a shape memory material, and combinations
thereof.
[0426] FIG. 7D shows therapeutic device 100 comprising porous
structure 150 positioned in an eye 10 to deliver a therapeutic
agent to a target location on or near the retina 26, for example
choroidal neovasculaturization of a lesion on or near the retina.
For example, the lesion may comprise one or more buckling, folding,
bending or separation of the retina from the choroid related to
neovascularization of corresponding vascular tissue associated with
blood supply to the retina, and the neovascular tissue
corresponding to the lesion of the retina may be targeted. Work in
relation to embodiments indicates that the vitreous humor 30 of the
eye may comprise convective current flows that extend along flow
paths 799. The convective flow paths may comprise flow channels.
Although small molecules can be delivered to a target location of
the retina 26 in accordance with the flow paths, therapeutic agent
comprising large molecules, for example with antibody fragments or
antibodies, can be delivered substantially with the convective flow
paths as the molecular diffusion of large molecules in the vitreous
humor can be somewhat lower than small molecules.
[0427] The therapeutic device can be sized such that porous
structure 150 is positioned along a flow path extending toward a
target location of the retina. The therapeutic agent can be
released along the flow path, such that the flow of vitreous humor
transports the therapeutic agent to the retina. The porous
structure can be disposed on a distal portion of the therapeutic
device, for example on a distal end, and the reservoir 130 can be
sized for delivery for the extended time. The retention structure
120 can be located on the proximal. The therapeutic device 100 can
be sized such that the porous structure is positioned in the flow
patch corresponding to the target region. The surgeon may identify
a target region 798 of the retina, for example corresponding to a
lesion, and the therapeutic device 100 can be positioned along the
pars plana or other location such that the therapeutic agent is
released to the target region.
[0428] FIG. 7E shows therapeutic device 100 comprising porous
structure 150 located on a proximal portion of the device to
deliver a therapeutic agent to one or more of the ciliary body or
the trabecular meshwork when implanted in the eye. The porous
structure 150 can be located near retention structure 120 such that
the porous structure is positioned in the vitreous substantially
away from the flow paths extending to retina, as noted above. The
porous structure can be located on a side of the therapeutic device
so as to release the therapeutic agent toward a target tissue.
While many therapeutic agents can be used, the therapeutic agent
may comprise a prostaglandin or analog, such as bimatoprost or
latanoprost, such that the therapeutic agent can be released toward
one or more of the ciliary body or trabecular meshwork when
implanted in the vitreous humor with the retention structure
coupled to the sclera.
[0429] FIG. 7F shows therapeutic device 100 comprising porous
structure 150 oriented to release the therapeutic agent 110 away
from the lens and toward the retina. For example, the therapeutic
agent 110 may comprise a steroid, and the steroid can be released
from porous structure 150 away from the lens and toward the retina.
For example, the porous structure can be oriented relative to an
axis 100A of the therapeutic device. The outer side of porous
structure 150 can be oriented at least partially toward the retina
and away from the lens, for example along a flow path as described
above so as to treat a target region of the retina. The barrier 160
can extend between the porous structure 160 and the lens of the eye
when implanted such that release of therapeutic agent toward the
lens can be inhibited with barrier 160. The retention structure 120
may comprise a long distance across and a short distance across as
described above. The porous structure can be oriented in relation
to the short and long distances of the extensions 122, such that
the outer side of porous structure 150 is oriented at least
partially toward the retina and along the flow path when the long
distance of the retention structure extends along the pars plana
and the short distance extends toward the pupil.
[0430] FIG. 7G shows a kit 789 comprising a placement instrument
750, a container 780, and a therapeutic device 100 disposed within
the container. The reservoir of the therapeutic device 100 disposed
in the container may comprise a non-therapeutic solution, for
example saline, such that the channels of the porous structure
comprise liquid water to inhibit bubble formation when the
formulation of therapeutic agent is injected into the device 100.
The kit may also comprise the syringe 188, needle 189 and stop 189S
to insert the needle tip to a maximum stop distance within the
reservoir as described above. The kit may contain instructions for
use 789I, and may contain a container 110C comprising a formulation
of therapeutic agent.
[0431] Tuning of Therapeutic Device for Sustained Release Based on
an Injection of a Formulation
[0432] The therapeutic device 100 can be tuned to deliver a target
therapeutic concentration profile based on the volume of
formulation injected into the device. The injected volume may
comprise a substantially fixed volume, for example within about
+/-30% of an intended pre-determined target volume. The volume of
the reservoir can be sized with the release rate index so as to
release the therapeutic agent for an extended time substantially
greater than the treatment time of a corresponding bolus injection.
The device can also be tuned to release the therapeutic agent based
on the half life of the therapeutic agent in the eye. The device
volume and release rate index comprise parameters that can be tuned
together based on the volume of formulation injected and the half
life of the therapeutic agent in the eye. The following equations
can be used to determine therapeutic device parameters suitable for
tuning the device.
Rate=Vr(dCr/dt)=-D(PA/TL)Cr
where Rate=Rate of release of therapeutic agent from device [0433]
Cr=concentration of therapeutic agent in reservoir [0434] Vr=volume
of reservoir [0435] D=Diffusion constant [0436] PA/TL=RRI [0437]
P=porosity [0438] A=area [0439] T=tortuosity=F=channel parameter.
[0440] For a substantially fixed volume injection,
[0440] Cr0=(Injection Volume)(Concentration of Formulation)/Vr
Where Cr0=initial concentration in reservoir following injection of
formulation [0441] For Injection Volume=50 uL
[0441] Cr0=(0.05 mL)(10 mg/mL)/Vr(1000 ug/1 mg)=500 ug/Vr
Rate=x(500 ug)exp(-xt) [0442] where t=time
[0442] x=(D/Vr)(PA/TL)
With a mass balance on the vitreous [0443] Vv(dCv/dt)=Rate from
device=kVvCv [0444] where Vv=volume of vitreous (about 4.5 ml)
[0445] Cv=concentration of therapeutic agent in vitreous [0446]
k=rate of drug from vitreous (proportional to 1/half life of drug
in vitreous) [0447] For the situation appropriate for the
embodiments as described herein where Cv remains substantially
constant and changes slowly with time (i.e. dCv/dt is approximately
0), [0448] Cv=(Rate from device)/(kVv) [0449] Since kVv is
substantially constant, the max value of Cv will correspond to
conditions that maximize the Rate from the device. At a given time
since injection into the device (e.g., 180 days), the maximum Cv is
found at the value of x that provides the maximum rate. The optimal
value of x satisfies [0450] d(Rate)/dx=0 at a given time. [0451]
Rate=500(x)exp(-xt)=f(x)g(x) where f(x)=500x and g(x)=exp(-xt)
[0452] d(Rate)/dx=f(x)g(x)+f(x)g'(x)=500(1-xt)exp(-xt) [0453] For a
given time, t, d(Rate)/dx=0 when 1-xt=0 and xt=1 [0454] The rate is
maximum when (D/Vr)(PA/TL)t=1. [0455] For a given volume, optimal
PA/TL=optimal RRI=Vr/(Dt) [0456] Therefore the highest Cv at a
given time, t, occurs for the optimal RRI=(PA/FL) for a given Vr.
[0457] Also, the ratio (Vr)/(RRI)=(Vr)/(PA/TL)=Dt will determine
the optimal rate at the time.
[0458] The above equations provide approximate optimized values
that, when combined with numerical simulations, can provide optimal
values of Vr and PA/TL. The final optimum value can depend on
additional parameters, such as the filling efficiency.
[0459] The above parameters can be used to determine the optimal
RRI, and the therapeutic device can be tuned to the volume of
formulation injected into the device with a device reservoir volume
and release rate index within about +/-50% of the optimal values,
for example +/-30% of the optimal values. For example, for an
optimal release rate index of the porous structure and an optimal
reservoir volume sized to receive a predetermined quantity of
therapeutic agent, e.g. 50 uL, so as to achieve therapeutic
concentrations above a minimum inhibitory concentration for a
predetermined extended time such as 90 days, the maximum volume of
the reservoir can be limited to no more than about twice the
optimal volume. This tuning of the reservoir volume and the porous
structure to the injected volume of the commercially available
formulation can increase the time of release of therapeutic amounts
from the device as compared to a much larger reservoir volume that
receives the same volume of commercially available injectable
formulation. Although many examples as described herein show a
porous frit structure and reservoir volume tuned together to
receive a quantity of formulation and provide release for an
extended time, the porous structure tuned with the reservoir may
comprise one or more of a porous frit, a permeable membrane, a
semi-permeable embrane, a capillary tube or a tortuous channel,
nano-structures, nano-channels or sintered nano-particles, and a
person of ordinary skill in the art can determine the release rate
characteristics, for example a release rate index, so as to tune
the one or more porous structures and the volume to receive the
quantity of the formulation and release therapeutic amounts for an
extended time.
[0460] As an example, the optimal RRI at 180 days can be determined
for a reservoir volume of about 125 uL. Based on the above
equations (Vr/Dt)=optimal RRI, such that the optimal RRI at 180
days is about 0.085 for the 50 uL formulation volume injected into
the device. The corresponding Cv is about 3.19 ug/mL at 180 days
based on the Rate of drug released from the device at 180 days and
the rate of the drug from the vitreous (k corresponding to a half
life of about 9 days). A device with a container reservoir volume
of 63 uL and RRI of 0.044 will also provide the optimal Cv at 180
days since the ratio of Vr to PA/TL is also optimal. Although an
optimal value can be determined, the therapeutic device can be
tuned to provide therapeutic amounts of drug at a targeted time,
for example 180 days, with many values of the reservoir volume and
many values of the release rate index near the optimal values, for
example within about +/-50% of the optimal values. Although the
volume of the reservoir can be substantially fixed, the volume of
the reservoir can vary, for example within about +/-50% as with an
expandable reservoir such as a balloon reservoir.
[0461] The half life of the drug in the vitreous humor of the eye
can be determined based on the therapeutic agent and the type of
eye, for example human, rabbit or monkey, such that the half life
may be determined based on the species of the eye, for example.
With at least some animal models the half life of the therapeutic
agent in the vitreous humor can be shorter than for human eyes, for
example by a factor of about two in at least some instances. For
example, the half-life of the therapeutic agent Lucentis.TM.
(ranibizumab) can be about nine days in the human eye and about two
to four days in the rabbit and monkey animal models. For small
molecules, the half life in the vitreous humor of the human eye can
be about two to three hours and can be about one hour in the monkey
and rabbit animal models. The therapeutic device can be tuned to
receive the volume of formulation based on the half life of the
therapeutic agent in the human vitreous humor, or an animal
vitreous humor, or combinations thereof. Based on the teachings
described herein, a person of ordinary skill in the art can
determine empirically the half life of the therapeutic agent in the
eye based on the type of eye and the therapeutic agent, such that
the reservoir and porous structure can be tuned together so as to
receive the volume of formulation and provide therapeutic amounts
for the extended time.
Experimental
EXAMPLE 1
[0462] FIG. 8 shows reservoirs with exit ports of defined diameters
fabricated from 1 mL syringes with Luer-Lok.TM. tips and needles of
varying diameter. The needles were trimmed to a total length of 8
mm, where 2 mm extended beyond the needle hub. Metal burrs were
removed under a microscope. FIG. 8-1 shows the needles attached to
syringes which were then filled with a solution of 2.4 mg/mL
fluorescein sodium, molecular weight 376 Da, in phosphate buffer
(Spectrum Chemicals, B-210.). Bubbles were removed and the syringes
were adjusted to be able to dispense 0.05 mL. The shape of the
resulting reservoir is shown in FIG. 8-1. The first expanded region
is defined by the inside of the needle hub and the tip of the
syringe. The second expanded region is inside the syringe. The
total volume of the reservoir is 0.14 mL.
[0463] Once filled, the outside of the reservoirs were rinsed of
excess fluorescein by submerging in PBS.
[0464] FIG. 8-2 shows the reservoirs placed into 4 mL vials
containing 1.5 mL buffer at room temperature. Collars cut from
rubber tubing were placed around the syringe barrels to position
the top of the reservoir to match the height of buffer in the vial
to avoid any pressure differential. The tops of the vials were
sealed with parafilm to avoid evaporation. At periodic intervals,
the reservoirs were moved to new vials containing buffer. The
amount of fluorescein transported from the reservoir through the
exit port was determined by measuring the amount of fluorescein in
the vials via absorption of visible light (492 nm).
TABLE-US-00004 TABLE 1C Release of Fluorescein through Exit Port
Needle Release Reservoir Needle ID Area Rate Number Gauge (mm)
(mm{circumflex over ( )}2) (ug/day) 1 18 0.838 0.552 10.8 2 18
0.838 0.552 9.4 3 23 0.318 0.079 1.0 4 23 0.318 0.079 1.2 5 30 0.14
0.015 0.6 6 30 0.14 0.015 0.6
[0465] The initial release rate (averaged over 0.5-4 days) is
proportional to the area of the exit port opening.
[0466] The cumulative amount released into the vials is shown in
FIG. 9. The amount released in a week ranged from 2 to 20%. An
average delivery rate was determined from the slope for data
collected between 0.5 and 4.5 days and is reported in Table 1C.
FIG. 10 shows that the initial release rate is approximately
proportional to the area of the exit port opening.
EXAMPLE 2
[0467] FIG. 11 shows reservoirs with a porous membrane fabricated
by cutting off the Luer-Lok tip on 1 mL syringes. The end of the
syringe was smoothed and beveled. A nylon membrane with 0.2 .mu.m
pore size was placed over the end of the syringe and secured with a
piece of silicone tubing. The inner diameter of the syringe was
4.54 mm, yielding an exposed membrane area of 16 mm.sup.2. The
piston was removed so that approximately 100 mL of 300 mg/mL bovine
serum albumin (BSA, Sigma A7906-100G) in PBS could be added. The
piston was replaced and moved to remove the air and to push a small
amount of the liquid through the membrane. The outside of the
membrane and syringe was rinsed by submerging briefly in water. The
reservoirs were then placed into 15 mL vials containing 5 mL PBS.
The tops of the vials were sealed with parafilm to avoid
evaporation. At periodic intervals of 0.5-1 day, the reservoirs
were moved to new vials containing PBS. Diffusion through the
membrane was determined by measuring the amount of BSA that
accumulated in the vials via absorption of visible light (280 nm).
The delivery rates from two replicates are shown in FIG. 11-1. This
data suggests that therapeutic agents of interest with molecular
weight on the order of 100 kDa will transport easily through porous
membranes with pore sizes of 0.2 um.
EXAMPLE 3
[0468] An experiment was performed to screen chromatographic media
(Bio-Rad) for binding to Human IgG (Jackson ImmunoResearch,
ChromPure). Columns were packed with the ten media listed below and
were equilibrated in 20 mM acetate buffer pH 4.5.
TABLE-US-00005 TABLE 2 Macro-Prep t-Butyl HIC Support Macro-Prep
DEAE Support CHT Ceramic Hydroxyapatite Type I 40 um Macro-Prep CM
Support Macro-Prep Methyl HIC Support Macro-Prep Ceramic
Hydroxyapatite Type II 40 um UNOsphere S Cation Exchange Support
UNOsphere Q Strong Anion Exchange Support Macro-Prep High S Support
Macro-Prep High Q Support
[0469] Then, 0.5 mL aliquots of 1 mg/mL antibody in 20 mM acetate
buffer pH 4.5 were gravity-driven through the column and the
collected solution was assessed qualitatively for color change
using a BCA.TM. protein assay kit (Pierce). Of the media tested,
Macro-Prep CM Support, Macro-Prep High S Support, and Macro-Prep
Ceramic Hydroxapatite Type II 40 um each successfully bound IgG.
Subsequently, PBS was washed through the columns and the IgG was
released from all three of these media.
Future Exit Port Studies
[0470] The experiments described in Examples 1-3 can be repeated
with agitation to explore the impact of mixing induced by eye
movement. In addition, the experiments can be performed at body
temperature where delivery rates would be expected to be higher
based upon faster diffusion rates at higher temperature.
[0471] Diffusion rates of BSA (MW 69 kDa) should be representative
of diffusion rates of Lucentis.TM. and Avastin.TM., globular
proteins with MW of 49 and 150 kDa, respectively. Selected
experiments could be repeated to confirm individual delivery rates
of these therapeutic agents.
[0472] Device prototypes closer to the embodiments described in the
body of the patent could be fabricated from metals (e.g., titanium
or stainless steel) or polymers (e.g., silicone or polyurethane).
Exit ports of defined areas can be created via ablation or
photo-etching techniques. In the case of polymers, exit ports can
also be created by molding the material with a fine wire in place,
followed by removal of the wire after the polymer is cured. Access
ports can be created using membranes of silicone or polyurethane.
Needle stops and flow diverters can be fabricated from metal or a
rigid plastic.
[0473] Device prototypes can be tested with methods similar to
those described in Example 1. Drug delivery rates can be measured
for pristine devices as well as devices that have been refilled.
Methods such as absorbance and fluorescence can be used to
quantitate the amount of therapeutic agent that has been delivered
as a function of time. Enzyme-Linked ImmunoSorbent Assays (ELISA)
can be used to monitor the stability of the biological therapeutic
agent in the formulations at 37.degree. C. and can be used to
determine the concentration of biologically active therapeutic
agent delivered as a function of time.
Future Membrane Studies
[0474] Experiments could be performed with a range of candidates to
identify membranes that 1) would be a barrier to bacteria and cells
without much resistance during refilling; 2) may contribute to
controlling the delivery rate of the therapeutic agent; and 3)
would be biocompatible. Candidate membranes would have pore sizes
of 0.2 .mu.m or smaller, approaching the size of the therapeutic
agents. A variety of fixtures can be used to secure a membrane
between a donor solution and a receiver solution to measure
permeation rates. In addition, performance of membranes can be
tested in device prototypes using methods similar to what was done
in Example 3.
[0475] Porous membranes could include cellulose acetate, nylon,
polycarbonate, and poly(tetrafluoroethylene) (PTFE), in addition to
regenerated cellulose, polyethersulfone, polyvinylidene fluoride
(PVDF).
Developing Binding Formulations and Conditions
[0476] Once media and conditions have been screened via the batch
or flow-through methods, devices can be fabricated containing the
binding media in place or with binding media injected along with
the therapeutic agent. Formulations can be prepared with the
desired excipients, and therapeutic agent delivery rates can be
monitored similarly to the method used in Example 1.
[0477] Additional media to test for binding include, ion exchange
and bioaffinity chromatography media based on a hydrophilic
polymeric support (GE Healthcare) that bind proteins with high
capacity, and a hydrophilic packing material from Harvard Apparatus
made from poly(vinyl alcohol) that binds more protein than silica.
Other candidates would be known to those knowledgeable in the
art.
[0478] A change in pH could modulate the binding of antibody to
media. For example, binding of antibody would be expected in a
formulation with cationic exchange media at an acidic pH. As the pH
becomes more neutral, the antibody may be released from the media.
Formulations could be tested that provide acidic pH for finite
durations (i.e., a few months). Once the pH has become neutral, the
release of antibody from the binding media could drive a higher
release rate, resulting in a more constant release rate
profile.
[0479] The binding media itself may have some buffering capacity
that could dominate until physiological buffer diffuses into the
device.
[0480] Alternatively, the formulation could include a buffer with a
buffering capacity selected to dominate during the first few
months. With time, the formulation buffer will diffuse out of the
device and physiological buffer will diffuse into the device, which
will result in a change of pH towards physiological pH (i.e.,
neutral). The kinetics of this change can be modulated by use of a
polymeric buffer, with a higher molecular weight buffer remaining
in the device for longer periods of time. Polypeptides are
attractive as biocompatible polymeric buffers because they degrade
to amino acids. Buffers are optimal near their pKa. The table below
lists the pKa of the side chains of amino acids of interest.
TABLE-US-00006 TABLE 3 Amino Acid pKa of side chain L-Aspartic Acid
3.8 L-Glutamic Acid 4.3 L-Arginine 12.0 L-Lysine 10.5 L-Histidine
6.08 L-Cysteine 8.28 L-Tyrosine 10.1
[0481] The formulation could include a polyester, such as PLGA, or
other biodegradable polymers such as polycaprolactone or
poly-3-hydroxybutyrate, to generate hydrogen ions for a finite
amount of time. The degradation rate could be modulated by, for
example, changing the composition or molecular weight of the PLGA,
such that the degradation is completed within a few months,
contributing to reaching neutral pH in the last few months of
delivery.
[0482] The pH could also be modulated electrochemically. Suitable
electrode materials include inert or non-consumable materials such
as platinum or stainless steel. Water hydrolysis occurs at the
electrode interfaces and the products of hydrolysis are hydronium
ions at the anode and hydroxyl ions at the cathode.
Rationale for Device Length
[0483] At least some device designs do not extend more than about 6
mm into the vitreous so as to minimize interference with vision. In
addition, it can be beneficial to have the device extend into the
vitreous since then drug can be released a distance from the walls
of the globe. Macromolecules, such as antibodies, are primarily
eliminated from the vitreous by a convection process rather than a
diffusion process. (see Computer Simulation of Convective and
Diffusive Transport of Controlled-Release Drugs in the vitreous
Humor, by Stay, M S; Xu, J, Randolph, T W; and V H Barocas, Pharm
Res 2003, 20(1), pp. 96-102.) Convection can be driven by the
pressure generated by the secretion of aqueous humor by the ciliary
body, with flow in the vitreous directed towards the retina. With
exit ports extending into the vitreous, it may be more likely that
drug will be convected towards the back of the eye and the central
retina, as opposed to a device with ports flush with the globe
likely delivering more of the therapeutic agent to the peripheral
retina.
Example 4: Comparison of Predicted vs. Measured Release Rates for a
Reservoir with One Orifice
[0484] The release study described in Example 1 using 23 and 30
gauge needles was continued through ten weeks. The results are
compared with a model relating the change of concentration in the
reservoir to the release rate from the reservoir based upon Fick's
Law of diffusion. This simple model assumes the concentration in
the reservoir is uniform and the concentration in the receiving
fluid or vitreous is negligible. Solving the differential equation
yields the following cumulative release of a therapeutic agent from
a reservoir with one orifice:
Cumulative Release=1-cR/cR0=1-exp((-D A/L VR) t),
where: [0485] c.sub.R=Concentration in reservoir [0486]
V.sub.R=Volume of reservoir [0487] D=Diffusion coefficient [0488]
A=Area of orifice [0489] L=Thickness of orifice [0490] t 32
Time
[0491] FIG. 12 shows the cumulative amount released into the vials
over 10 weeks and the predicted cumulative amount release. These
data show that the release from model devices generally agrees with
the trend predicted by this model with no adjustable fitting
parameters.
Example 5: Release of Protein through a Cylindrical Sintered Porous
Titanium Cylinder
[0492] Reservoirs were fabricated from syringes and sintered porous
titanium cylinders (available from Applied Porous Technologies,
Inc., Mott Corporation or Chand Eisenmann Metallurgical). These
were sintered porous cylinders with a diameter of 0.062 inches and
a thickness of 0.039 inches prepared from titanium particles. The
porosity is 0.17 with mean pore sizes on the order of 3 to 5
micrometers. The porous cylinder is characterized as 0.2 media
grade according to measurements of bubble point. The porous
cylinders were press-fit into sleeves machined from Delrin. The
sleeves exposed one entire planar face to the solution in the
reservoir and the other entire planar face to the receiver solution
in the vials, corresponding to an area of 1.9 square millimeters.
The tips were cut off of 1 mL polypropylene syringes and machined
to accept a polymer sleeve with outer diameter slightly larger than
the inner diameter of the syringe. The porous cylinder/sleeve was
press-fit into the modified syringe.
[0493] A solution was prepared containing 300 mg/mL bovine serum
albumin (BSA, Sigma, A2153-00G) in phosphate buffered saline (PBS,
Sigma, P3813). Solution was introduced into the syringes by
removing the piston and dispensing approximately 200 microliters
into the syringe barrel. Bubbles were tapped to the top and air was
expressed out through the porous cylinder. Then BSA solution was
expressed through the porous cylinder until the syringe held 100 uL
as indicated by the markings on the syringe. The expressed BSA
solution was wiped off and then rinsed by submerging in PBS. The
reservoirs were then placed into 4 mL vials containing 2 mL PBS at
room temperature. Collars cut from silicone tubing were placed
around the syringe barrels to position the top of the reservoir to
match the height of PBS. The silicone tubing fit inside the vials
and also served as a stopper to avoid evaporation. At periodic
intervals, the reservoirs were moved to new vials containing PBS.
The amount of BSA transported from the reservoir through the porous
cylinder was determined by measuring the amount of BSA in the vials
using a BCA.TM. Protein Assay kit (Pierce, 23227).
[0494] FIG. 13 shows the measured cumulative release of BSA through
a sintered porous titanium disc and a prediction from the model
describing release through a porous body. The Channel Parameter of
1.7 was determined via a least squares fit between the measured
data and the model (MicroSoft Excel). Since the porous cylinder has
equal areas exposed to the reservoir and receiving solution, the
Channel Parameter suggests a tortuosity of 1.7 for porous titanium
cylinders prepared from 0.2 media grade.
[0495] FIG. 13-1 shows the measured cumulative release of BSA of
FIG. 13 measured to 180 days. The Channel Parameter of 1.6 was
determined via a least squares fit between the measured data and
the model (MicroSoft Excel). This corresponds to a Release Rate
Index of 0.21 mm. Since the porous cylinder has equal areas exposed
to the reservoir and receiving solution, the Channel Parameter
corresponds to an effective path length channel parameter of 1.6
and suggests a tortuosity of 1.6 for porous titanium cylinders
prepared from 0.2 media grade.
Example 6: Release of Protein through Masked Sintered Porous
Titanium Cylinders
[0496] Reservoirs were fabricated from syringes and porous sintered
titanium cylinders similar to that described in Example 5. The
porous sintered titanium cylinders (available from Applied Porous
Technologies, Inc., Mott Corporation or Chand Eisenmann
Metallurgical) had a diameter of 0.082 inch, a thickness of 0.039
inch, a media grade of 0.2 and were prepared from titanium
particles. The porosity is 0.17 with mean pore sizes on the order
of 3 to 5 micrometers. The porous cylinder is characterized as 0.2
media grade according to measurements of bubble point. The porous
cylinders were press fit into sleeves machined from Delrin. The
sleeves exposed one entire planar face to the solution in the
reservoir and the other entire planar face to the receiver solution
in the vials, corresponding to an area of 3.4 square millimeters.
The tips were cut off of 1 mL polycarbonate syringes and machined
to accept a polymer sleeve with outer diameter slightly larger than
the inner diameter of the syringe. The porous cylinder/sleeve was
press fit into the modified syringe. A kapton film with adhesive
was affixed to the surface exposed to the receiving solution to
create a mask and decrease the exposed area. In the first case, the
diameter of the mask was 0.062 inches, exposing an area of 1.9
square millimeters to the receiving solution. In a second case, the
diameter of the mask was 0.027 inches, exposing an area of 0.37
square millimeters.
[0497] Three conditions were run in this study: 1) 0.062 inch
diameter mask, 100 uL donor volume, at room temperature in order to
compare with reservoirs with unmasked porous cylinders in Example
5; 2) 0.062 inch diameter mask, 60 uL donor volume, at 37.degree.
C.; and 3) 0.027 inch diameter mask, 60 uL donor volume, at
37.degree. C. The syringes were filled with a solution containing
300 mg/mL bovine serum albumin (BSA, Sigma, A2153-00G) in phosphate
buffered saline (Sigma, P3813), similar to Example 5. In addition,
0.02 wt% of sodium azide (Sigma, 438456-5G) was added as a
preservative to both the BSA solution placed in the reservoirs and
the PBS placed in the receiving vials and both solutions were
filtered through a 0.2 micron filter. This time, the amount of BSA
solution dispensed into the syringe was weighed and the amount
expressed through the porous cylinder was determined by rinsing and
measuring the amount of BSA in the rinse. Assuming unit density for
the BSA solution, the amount dispensed was 113+/-2 uL (Condition 1)
and 66+/-3 uL (Condition 2). Subtracting off the amount in the
rinse yielded a final reservoir volume of 103+/-5 uL (Condition 1)
and 58+/-2 uL (Condition 2). The reservoirs were then placed into 5
mL vials containing 1 mL PBS at 37.degree. C. in a heating block.
At periodic intervals, the reservoirs were moved to new vials
containing PBS and the BSA concentrations were determined in the
receiving solutions using the method described in Example 5.
[0498] FIG. 14 shows the cumulative release of BSA protein through
a masked sintered porous Titanium disc at Condition 1 (0.062 inch
diameter mask, 100 uL donor volume, at room temperature) is faster
than the release through an unmasked porous cylinder with the same
exposed area (data from Example 5). Predictions are also shown
using the Channel Parameter of 1.7 determined in Example 5, BSA
diffusion coefficient at 20.degree. C. (6.1 e-7 cm.sup.2/s),
reservoir volume of 100 uL, and the area of the porous cylinder
exposed to the receiver solution (A=1.9 mm.sup.2) or the area of
the porous cylinder exposed to the reservoir (A=3.4 mm.sup.2). The
data for the masked porous cylinder matches more closely with
larger area exposed to the reservoir. Hence, this mask with width
of 0.7 mm is not sufficient to reduce the effective area of the
porous cylinder for the dimensions of this porous cylinder.
[0499] FIG. 15 shows the cumulative release of BSA protein through
a masked sintered porous titanium cylinder at Condition 2 (0.062
inch diameter mask, 60 uL donor volume, at 37.degree. C.). The
figure also displays predictions using the Channel Parameter of 1.7
determined in Example 5, BSA diffusion coefficient at 37.degree. C.
(9.1 e-7 cm.sup.2/s), reservoir volume of 58 uL, and the area of
the porous cylinder exposed to the receiver solution (A=1.9
mm.sup.2) or the area of the porous cylinder exposed to the
reservoir (A=3.4 mm.sup.2). Again, the data for this masked porous
cylinder matches more closely with larger area exposed to the
reservoir. The consistency of the data with the model at two
temperatures supports how the model incorporates the effect of
temperature.
[0500] FIG. 16 shows the cumulative release of BSA protein through
a masked sintered porous titanium cylinder at Condition 3 (0.027
inch diameter mask, 60 uL donor volume, at 37.degree. C.). The
figure also displays predictions using the Channel Parameter of 1.7
determined in Example 5, BSA diffusion coefficient at 37.degree. C.
(9.1 e-7 cm.sup.2/s), reservoir volume of 58 uL, and the area of
the porous cylinder exposed to the receiver solution (A=0.37
mm.sup.2) or the area of the porous cylinder exposed to the
reservoir (A=3.4 mm.sup.2). This mask achieves a release rate
corresponding to an effective area in between the area exposed to
the reservoir and the area exposed to the receiver solution. A
combination of the results in FIGS. 15 and 16 demonstrate that
slower release is achieved using a mask that exposes a smaller area
to the receiver solution.
[0501] FIGS. 13-16 show an unexpected result. Masking of the area
of the porous frit structure so as to decrease the exposed area of
the porous structure decreased the release rate less than the
corresponding change in area. The release rate through the porous
structure corresponds substantially to the interconnecting channels
of the porous frit structure disposed between the first side
exposed to the reservoir and the second side exposed to the
receiver solution, such that the rate of release is maintained when
a portion of the porous frit structure is covered. The rate of
release of the interconnecting channels corresponds substantially
to an effective area of the porous frit structure, and the
effective area may correspond to an effective area of the
interconnecting channels within the porous structure as shown
above. As the rate of release is dependent upon the interconnecting
channels, the release rate can be maintained when at least some of
the channels are blocked, for example with coverage of a portion of
the porous structure or blocking of a portion of the
interconnecting channels with particles.
Example 7: Release of protein through sintered porous stainless
steel cylinder (media grade 0.1)
[0502] Prototype devices were fabricated from tubing and sintered
porous stainless steel cylinders (available from Applied Porous
Technologies, Inc., Mott Corporation or Chand Eisenmann
Metallurgical) which are cylindrical with diameter 0.155 inch and
thickness 0.188 inch prepared from 316 L stainless steel particles.
The porous cylinder is characterized as 0.1 media grade according
to measurements of bubble point. This study was performed with
these large, off-the-shelf porous cylinders with an area of 12
mm.sup.2 in order to characterize the resistive properties of 0.1
media grade stainless steel.
[0503] These devices were prepared using Teflon-FEP heat shrink
tubing (Zeus, #37950) and a hot air gun to shrink around the porous
cylinders on one end and a custom prepared septum on the other end
(Nusil MED1 4013 silicone molded to 0.145 inch diameter). The
reservoir volume (46+/-2 uL) was determined from the difference in
weight between empty systems and systems loaded with PBS. The PBS
was loaded by submerging the systems in PBS and drawing a vacuum.
The systems were then sterilized by heating to 250.degree. F., 15
psi for 15 minutes, submerged in PBS in microcentrifuge tubes
placed in a pressure cooker (Deni, 9760). Two 30 G needles were
inserted into the septum to displace the PBS with BSA solution. One
was used to inject the BSA solution and the other was bent and used
as a vent for the displaced PBS. Sufficient BSA solution was
injected to fill the needle hub of the vent to approximately 3/4
full. Similar to Example 6, the BSA and PBS contained sodium azide
and the nominal concentration was 300 mg/mL BSA. The devices were
placed into 1.5 mL microcentrifuge tubes containing 1 mL PBS and
kept at 37.degree. C. in a heating block. Pieces of silicone tubing
(tight fit with inside of tube, hole for septum) were used to
suspend the devices in the PBS with the bottom of the septum
approximately the same height as the PBS. The concentrations in the
first tubes contained BSA from the filling process and were
discarded. At periodic intervals, the devices were moved to new
tubes containing PBS and the BSA concentrations were determined in
the receiving solutions using the method described in Example
5.
[0504] FIG. 17 displays the measured cumulative release of BSA
through the 0.1 media grade stainless steel sintered titanium
discs. Since the Porosity, P, is not available from the vendor at
this time, a single parameter of Porosity divided by Channel
Parameter was determined by least squares fit of the model to the
data. Since the sintered porous structure is cylindrical, the
Channel Parameter can be interpreted as the Tortuosity, T, and P/T
was determined to be equal to 0.07.
Example 8: Release of Protein through a Sintered Porous Stainless
Steel Cylinder (Media Grade 0.2)
[0505] Prototype devices were fabricated from tubing and sintered
porous stainless steel cylinders (available from Applied Porous
Technologies, Inc., Mott Corporation or Chand Eisenmann
Metallurgical) which are cylindrical with diameter 0.031 inch, and
thickness 0.049 inch prepared from 316L stainless steel particles.
The porous cylinder is characterized as 0.2 media grade according
to measurements of bubble point. This porous cylinder was obtained
as a custom order with properties determined from a previous study
with a large diameter 0.2 media grade porous stainless steel
cylinder (data no shown) and predictions based on the model
described herein. The area of each face of this porous cylinder is
0.5
[0506] These devices were prepared using Teflon-FEP heat shrink
tubing (Zeus, 0.125 inch OD) and a hot air gun to shrink around the
porous cylinder on one end and a custom prepared septum on the
other end (Nusil MED1 4013 silicone molded to 0.113 inch diameter).
The reservoir volume (17+/-1 uL) was determined from the difference
in weight between empty systems and systems filled with PBS. The
PBS was loaded by submerging the systems in PBS and drawing a
vacuum. Dry devices were submerged in PBS in microcentrifuge tubes
and sterilized by heating to 250.degree. F., 15 psi for 15 minutes
in a pressure cooker (Deni, 9760). Two 30 G needles were inserted
into the septum to fill the devices with PBS. One was used to
inject the PBS and the other was bent and used as a vent. After
weighing the PBS filled devices, two new needles were inserted
through the septum and sufficient BSA solution was injected to fill
the needle hub of the vent to approximately 3/4 full. The remaining
details of the experiment are the same as Example 7.
[0507] FIG. 18A displays the measured cumulative release of BSA
through the 0.2 media grade sintered porous stainless steel
cylinder. A single parameter of Porosity divided by Channel
Parameter was determined to be 0.12 by least squares fit of the
model to the data. Since the sintered porous structure is
cylindrical, the Channel Parameter can be interpreted as effective
length of the interconnecting channels that may correspond the
Tortuosity, T. Using the Porosity of 0.17 determined by the vendor,
the effective length of the channel that may correspond to the
Tortuosity was determined to be 1.4. Furthermore, this corresponds
to a PA/FL ratio (Release Rate Index) of 0.0475 mm.
[0508] FIG. 18B displays the measured cumulative release of BSA
through the 0.2 media grade sintered porous stainless steel
cylinder for 180 days. A single parameter of Porosity divided by
Channel Parameter was determined to be 0.10 by least squares fit of
the model to the data. Since the sintered porous structure is
cylindrical, the Channel Parameter can be interpreted an effective
length of the inter-connecting channels that may correspond to the
Tortuosity, T. Using the Porosity of 0.17 determined by the vendor,
the effective channel length of the inter-connecting channels that
may correspond to the Tortuosity was determined to be 1.7.
Furthermore, this corresponds to a PA/FL ratio (Release Rate Index)
of 0.038 mm.
Example 9: Calculations of Lucentis.TM. Concentrations in the
Vitreous
[0509] The vitreous concentrations of a therapeutic agent can be
predicted based on the equations described herein. Table 4 shows
the values of the parameters applied for each of Simulation 1,
Simulation 2, Simulation 3, Simulation 4, and Simulation 5. The
half-life and vitreous volume correspond to a monkey model (J.
Gaudreault et al., Preclinical Pharmacokinetics of Ranibizumab
(rhuFabV2) after a Single Intravitreal Administration, Invest
Ophthalmol Vis Sci 2005; 46: 726-733) (Z. Yao et al., Prevention of
Laser Photocoagulation Induced Choroidal Neovascularization Lesions
by Intravitreal Doses of Ranibizumab in Cynomolgus Monkeys, ARVO
2009 abstract D906). The parameter PA/FL can be varied to determine
the release rate profile. For example, the value of A can be about
1 mm.sup.2, the porosity can be about 0.1 (PA=0.1 mm.sup.2) and the
length about 1 mm and the channel fit parameter that may correspond
to tortuousity can be about 2 (FL=2 mm), such that PA/TL is about
0.05 mm. A person of ordinary skill in the art can determine
empirically the area, porosity, length and channel fit parameter
for extended release of the therapeutic agent for the extended
period based on the teachings described herein.
TABLE-US-00007 TABLE 4A Values Values Values Values Values
Parameter Simulation 1 Simulation 2 Simulation 3 Simulation 4
Simulation 5 Diffusion coeff (cm2/s) 1.0E-06 1.0E-06 1.0E-06
1.0E-06 1.0E-06 Initial Loading (ug/mL) 10000 10000 10000 10000
10000 Reservoir Vol (ml) 0.05 0.01 0.05 0.01 0.017 PA/FL (mm)
0.0225 0.0225 0.045 0.045 0.047 Half-life (days) 2.63 2.63 2.63
2.63 2.63 Rate constant, k (1/day) 0.264 0.264 0.264 0.264 0.264
Vitreous vol (ml) 1.5 1.5 1.5 1.5 1.5
[0510] Table 4B shows the vitreous concentrations calculated for a
0.5 mg bolus injection of Lucentis.TM. injected into the eye of a
monkey using equations described herein and the half-life measured
for the monkey listed in Table 4A. The first column used the
measured Cmax (Gaudreault et al.) while the second used a
calculated Cmax based on the dose and volume of the vitreous. The
average concentration of Lucentis.TM. is about 46 ug/ml. The
minimum therapeutic concentration of Lucentis.TM. is about 0.1
ug/mL, which may correspond to about 100% VGEF inhibition
(Gaudreault et al.). Table 4B indicates that a bolus injection of
0.5 mg Lucentis.TM. maintains a vitreous concentration above 0.1
ug/mL for about a month whether using the measured or calculated
Cmax. This is consistent with monthly dosing that has been shown to
be therapeutic in clinical studies.
TABLE-US-00008 TABLE 4B Predicted Vitreous Predicted Vitreous Time
Conc using Meas Cmax Conc using Calc Cmax (days) (ug/mL) (ug/mL) 0
169.00 333.33 1 129.85 256.11 2 99.76 196.77 3 76.65 151.18 4 58.89
116.16 5 45.25 89.24 6 34.76 68.57 7 26.71 52.68 8 20.52 40.48 9
15.77 31.10 10 12.11 23.89 11 9.31 18.36 12 7.15 14.10 13 5.49
10.84 14 4.22 8.33 15 3.24 6.40 16 2.49 4.91 17 1.91 3.78 18 1.47
2.90 19 1.13 2.23 20 0.87 1.71 21 0.67 1.32 22 0.51 1.01 23 0.39
0.78 24 0.30 0.60 25 0.23 0.46 26 0.18 0.35 27 0.14 0.27 28 0.11
0.21 29 0.08 0.16 30 0.06 0.12 31 0.05 0.09 32 0.04 0.07
[0511] Tables 4C1, 4C2, 4C3 4C4, and 4C5 show the calculated
concentration of Lucenti.TM. in the vitreous humor for Simulation
1, Simulation 2, Simulation 3, Simulation 4, and Simulation 5
respectively. These results indicate Lucentis.TM. vitreous
concentrations may be maintained above the minimum therapeutic
level for about a year or more when released from a device with
porous structure characterized by PA/FL.ltoreq.0.0225 mm and a
reservoir volume.gtoreq.10 uL.
[0512] Simulation 5 corresponds to the devices used in the
experiment described in Example 8. This device had a reservoir
volume of 17 uL and porous structure characterized by PA/FL=0.047
mm. When this device is loaded with Lucentis.TM., the loading dose
corresponds to 1/3 of the 50 uL currently injected monthly.
Calculations that predict vitreous concentrations indicate that
this device with one-third of the monthly dose may maintain
Lucentis .TM. therapeutic concentrations for about 6 months. While
half of the dose is delivered in the first month and more than 98%
delivered at 6 months, therapeutic levels may still be maintained
for 6 months.
[0513] The ability of the device to release therapeutic agent for
an extended time can be described by an effective device half-life.
For the device in Example 8, the effective device half-life is 29
days for delivery of Lucentis.TM.. The device can be configured by
selection of the reservoir volume and a porous structure with an
appropriate PA/FL to achieve the desired effective half-life.
TABLE-US-00009 TABLE 4C1 Simulation 1 Time Predicted Rate Predicted
Predicted Vitreous Conc (days) (ug/day) % CR (ug/mL) 0 1.9 0.0% 4.9
10 1.9 3.8% 4.7 20 1.8 7.5% 4.5 30 1.7 11.0% 4.4 40 1.7 14.4% 4.2
50 1.6 17.7% 4.0 60 1.5 20.8% 3.9 70 1.5 23.8% 3.7 80 1.4 26.7% 3.6
90 1.4 29.5% 3.5 100 1.3 32.2% 3.3 110 1.3 34.8% 3.2 120 1.2 37.3%
3.1 130 1.2 39.7% 3.0 140 1.1 42.0% 2.9 150 1.1 44.2% 2.7 160 1.0
46.3% 2.6 170 1.0 48.4% 2.5 180 1.0 50.3% 2.4 190 0.9 52.2% 2.3 200
0.9 54.0% 2.3 210 0.9 55.8% 2.2 220 0.8 57.5% 2.1 230 0.8 59.1% 2.0
240 0.8 60.7% 1.9 250 0.7 62.2% 1.9 260 0.7 63.6% 1.8 270 0.7 65.0%
1.7 280 0.7 66.3% 1.7 290 0.6 67.6% 1.6 300 0.6 68.9% 1.5 310 0.6
70.0% 1.5 320 0.6 71.2% 1.4 330 0.5 72.3% 1.4 340 0.5 73.3% 1.3 350
0.5 74.4% 1.3 360 0.5 75.3% 1.2
TABLE-US-00010 TABLE 4C2 Simulation 2 Time Predicted Rate Predicted
Predicted Vitreous Conc (days) (ug/day) % CR (ug/mL) 0 1.9 0.0%
4.92 10 1.6 17.7% 4.05 20 1.3 32.2% 3.33 30 1.1 44.2% 2.74 40 0.9
54.0% 2.26 50 0.7 62.2% 1.86 60 0.6 68.9% 1.53 70 0.5 74.4% 1.26 80
0.4 78.9% 1.04 90 0.3 82.6% 0.85 100 0.3 85.7% 0.70 110 0.2 88.2%
0.58 120 0.2 90.3% 0.48 130 0.2 92.0% 0.39 140 0.1 93.4% 0.32 150
0.1 94.6% 0.27 160 0.1 95.5% 0.22 170 0.1 96.3% 0.18 180 0.1 97.0%
0.15 190 0.0 97.5% 0.12 200 0.0 98.0% 0.10 210 0.0 98.3% 0.08 220
0.0 98.6% 0.07 230 0.0 98.9% 0.06 240 0.0 99.1% 0.05 250 0.0 99.2%
0.04 260 0.0 99.4% 0.03 270 0.0 99.5% 0.03 280 0.0 99.6% 0.02 290
0.0 99.6% 0.02 300 0.0 99.7% 0.01 310 0.0 99.8% 0.01 320 0.0 99.8%
0.01 330 0.0 99.8% 0.01 340 0.0 99.9% 0.01 350 0.0 99.9% 0.01 360
0.0 99.9% 0.00
TABLE-US-00011 TABLE 4C3 Simulation 3 Time Predicted Rate Predicted
Predicted Vitreous Conc (days) (ug/day) % CR (ug/mL) 0 3.9 0.0% 9.8
10 3.6 7.5% 9.1 20 3.3 14.4% 8.4 30 3.1 20.8% 7.8 40 2.8 26.7% 7.2
50 2.6 32.2% 6.7 60 2.4 37.3% 6.2 70 2.3 42.0% 5.7 80 2.1 46.3% 5.3
90 1.9 50.3% 4.9 100 1.8 54.0% 4.5 110 1.7 57.5% 4.2 120 1.5 60.7%
3.9 130 1.4 63.6% 3.6 140 1.3 66.3% 3.3 150 1.2 68.9% 3.1 160 1.1
71.2% 2.8 170 1.0 73.3% 2.6 180 1.0 75.3% 2.4 190 0.9 77.2% 2.2 200
0.8 78.9% 2.1 210 0.8 80.5% 1.9 220 0.7 81.9% 1.8 230 0.7 83.3% 1.6
240 0.6 84.5% 1.5 250 0.6 85.7% 1.4 260 0.5 86.8% 1.3 270 0.5 87.7%
1.2 280 0.4 88.7% 1.1 290 0.4 89.5% 1.0 300 0.4 90.3% 1.0 310 0.3
91.0% 0.9 320 0.3 91.7% 0.8 330 0.3 92.3% 0.8 340 0.3 92.9% 0.7 350
0.3 93.4% 0.6 360 0.2 93.9% 0.6
TABLE-US-00012 TABLE 4C4 Simulation 4 Time Predicted Rate Predicted
Predicted Vitreous Conc (days) (ug/day) % CR (ug/mL) 0 3.89 0.0%
9.83 10 2.64 32.2% 6.67 20 1.79 54.0% 4.52 30 1.21 68.9% 3.06 40
0.82 78.9% 2.08 50 0.56 85.7% 1.41 60 0.38 90.3% 0.95 70 0.26 93.4%
0.65 80 0.17 95.5% 0.44 90 0.12 97.0% 0.30 100 0.08 98.0% 0.20 110
0.05 98.6% 0.14 120 0.04 99.1% 0.09 130 0.02 99.4% 0.06 140 0.02
99.6% 0.04 150 0.01 99.7% 0.03 160 0.01 99.8% 0.02 170 0.01 99.9%
0.01 180 0.00 99.9% 0.01 190 0.00 99.9% 0.01 200 0.00 100.0% 0.00
210 0.00 100.0% 0.00 220 0.00 100.0% 0.00 230 0.00 100.0% 0.00 240
0.00 100.0% 0.00 250 0.00 100.0% 0.00 260 0.00 100.0% 0.00 270 0.00
100.0% 0.00 280 0.00 100.0% 0.00 290 0.00 100.0% 0.00 300 0.00
100.0% 0.00 310 0.00 100.0% 0.00 320 0.00 100.0% 0.00 330 0.00
100.0% 0.00 340 0.00 100.0% 0.00 350 0.00 100.0% 0.00 360 0.00
100.0% 0.00
TABLE-US-00013 TABLE 4C5 Simulation 5 Time Predicted Rate Predicted
Predicted Vitreous Conc (days) (ug/day) % CR (ug/mL) 0 4.1 0.0%
10.27 10 3.2 21.2% 8.09 20 2.5 38.0% 6.37 30 2.0 51.2% 5.02 40 1.6
61.5% 3.95 50 1.2 69.7% 3.11 60 1.0 76.1% 2.45 70 0.8 81.2% 1.93 80
0.6 85.2% 1.52 90 0.5 88.3% 1.20 100 0.4 90.8% 0.94 110 0.3 92.8%
0.74 120 0.2 94.3% 0.58 130 0.2 95.5% 0.46 140 0.1 96.5% 0.36 150
0.1 97.2% 0.29 160 0.1 97.8% 0.22 170 0.1 98.3% 0.18 180 0.1 98.6%
0.14 190 0.0 98.9% 0.11 200 0.0 99.2% 0.09 210 0.0 99.3% 0.07 220
0.0 99.5% 0.05 230 0.0 99.6% 0.04 240 0.0 99.7% 0.03 250 0.0 99.7%
0.03 260 0.0 99.8% 0.02 270 0.0 99.8% 0.02 280 0.0 99.9% 0.01 290
0.0 99.9% 0.01 300 0.0 99.9% 0.01 310 0.0 99.9% 0.01 320 0.0 100.0%
0.00 330 0.0 100.0% 0.00 340 0.0 100.0% 0.00 350 0.0 100.0% 0.00
360 0.0 100.0% 0.00
[0514] Z. Yao et al. (Prevention of Laser Photocoagulation Induced
Choroidal Neovascularization Lesions by Intravitreal Doses of
Ranibizumab in Cynomolgus Monkeys, ARVO 2009 abstract D906) have
performed a preclinical study to determine the lowest efficacious
Lucentis.TM. dose in cynomolgus monkeys that leads to 100%
prevention of laser photocoagulation treatment-induced Grade IV
choroidal neovascularization (CNV) lesions. .TM. This model has
been shown to be relevant to AMD. Intravitreal injection of
Lucentis.TM. at all doses tested completely inhibited the
development of Grade IV CNV lesions. Table 4D shows predictions of
Lucentis.TM. vitreous concentrations for the lowest total amount of
Lucentis.TM. investigated (intravitreal injection of 5 ug on days
1, 6, 11, 16, 21 and 26), using the equations described herein and
pharmacokinetic parameters listed in Table 4A. This data indicates
that it is not necessary to achieve the high Cmax of a 0.5 mg
single bolus injection in order to be therapeutic.
[0515] FIG. 19A compares this predicted profile with that predicted
for the device in Example 8. This data further supports that the
release profile from a device in accordance with embodiments of the
present invention may be therapeutic for at least about 6 months.
The single injection of 500 ug corresponds to a 50 uL bolus
injection of Lucentis.TM. that can given at monthly intervals, and
the range of therapeutic concentrations of Lucentis.TM.
(ranibizumab) in the vitreous extends from about 100 ug/mL to the
minimum inhibitory (therapeutic) concentration of about 0.1 ug/mL
at about 1 month, for example. The minimum inhibitory concentration
corresponding to the lower end of the range of therapeutic
concentrations in the vitreous humor can be determined empirically
by one of ordinary skill in the art in accordance with the examples
described herein. For example, a lose does study of a series of six
Lucentis.TM. injections, 5 ug each, can be administered so as to
provide a concentration in the vitreous of at least about 1 ug/mL,
and the therapeutic benefit of the injections assessed as described
herein.
TABLE-US-00014 TABLE 4D Time Predicted Lucentis Vitreous Conc
(days) (ug/mL) 0 0.00 1 3.33 2 2.56 3 1.97 4 1.51 5 1.16 6 4.23 7
3.25 8 2.49 9 1.92 10 1.47 11 4.46 12 3.43 13 2.64 14 2.02 15 1.56
16 4.53 17 3.48 18 2.67 19 2.05 20 1.58 21 4.55 22 3.49 23 2.68 24
2.06 25 1.58 26 4.55 27 3.50 28 2.69 29 2.06 30 1.59 35 0.42 40
0.11 45 0.03 50 0.01 60 0.00 70 0.00 80 0.00 90 0.00
[0516] The concentration profiles of a therapeutic agent comprising
Lucentis.TM. were determined as shown below based on the teachings
described herein and with drug half-life of nine days for
Lucentis.TM. in the human eye. The examples shown below for
injections of the commercially available formulation Lucentis.TM.
and the nine day half life show unexpected results, and that a
volume of formulation corresponding to a monthly bolus injection
into the device as described herein can provide therapeutic benefit
for at least about two months. The device volume and the porous
structure can be tuned to receive the predetermined volume of
formulation and provide sustained release for an extended time.
Additional tuning of the device can include the half-life of the
therapeutic agent in the eye, for example nine days for
Lucentis.TM., and the minimum inhibitory concentration of the
therapeutic agent as determined based on the teachings as described
herein.
[0517] FIG. 19B shows determined concentrations of Lucentis.TM. in
the vitreous humor for a first 50 uL injection into a 25 uL device
and a second 50 uL injection at 90 days. The calculations show that
the 50 uL dosage of the monthly FDA approved bolus injection can be
used to treat the eye for about 90 days, and that the injections
can be repeated to treat the eye, for example at approximately 90
day intervals. The Lucentis.TM. may comprise a predetermined amount
of the commercially available formulation injected into the device.
The commercially available formulation of Lucentis.TM. has a
concentration of ranibizumab of 10 mg/mL, although other
concentrations can be used for example as described herein below
with reference to a 40 mg/mL solution of injected ranibizumab. The
predetermine amount corresponds to the amount of the monthly bolus
injection, for example 50 uL. The therapeutic device may comprise a
substantially fixed volume container reservoir having a volume of
25 uL, such that a first 25 uL portion of the 50 uL injection is
contained in the reservoir for sustained and/or controlled release
and a second 25 uL portion of the 50 uL injection is passed through
the porous structure and released into the vitreous with a 25 uL
bolus. The filling efficiency of the injection into the device may
comprise less than 100%, and the reservoir volume and injection
volume can be adjusted based on the filling efficiency in
accordance with the teachings described herein. For example, the
filling efficiency may comprise approximately 90%, such that the
first portion comprises approximately 22.5 uL contained in the
chamber of the container reservoir and the second portion comprises
approximately 27.5 uL passed through the device for the 50 uL
injected into the therapeutic device. The initial concentration of
Lucentis.TM. in the vitreous humor corresponds to about 60 ug/mL
immediately following injection into the reservoir device. The
concentration of Lucentis.TM. in the vitreous humor decreases to
about 3.2 ug/mL at 90 days. A second 50 uL injection of
Lucentis.TM. approximately 90 days after the first injection
increases the concentration to about 63 ug/mL. The concentration of
Lucentis.TM. in the vitreous humor decreases to about 3.2 ug/mL at
180 days after the first injection and 90 days after the second
injection. These calculations show that the concentration of
Lucentis.TM. can be continuously maintained above a minimum
inhibitory concentration of about 3 ug per ml with the 50 uL
injection into the device. Additional injections can be made, for
example every 90 days for several years to deliver the therapeutic
agent to treat the patient.
[0518] FIG. 19C shows determined concentrations of Lucentis.TM. in
the vitreous humor for a first 50 uL injection into a 32 uL device
and a second 50 uL injection at a time greater than 90 days. The
calculations show that the 50 uL dosage of the monthly FDA approved
bolus injection can be used to treat the eye for about 90 days, and
that the injections can be repeated to treat the eye, for example
at approximately 90 day intervals. The Lucentis.TM. may comprise a
predetermined amount of the commercially available formulation
injected into the device. The predetermine amount corresponds to
the amount of the monthly bolus injection, for example 50 uL. The
therapeutic device may comprise a substantially fixed volume
container reservoir having a volume of 32 uL, such that a first 32
uL portion of the 50 uL injection is contained in the reservoir for
sustained and/or controlled release and a second 18 uL portion of
the 50 uL injection is passed through the porous structure and
released into the vitreous with an 18 uL bolus. The filling
efficiency of the injection into the device may comprise less than
100%, and the reservoir volume and injection volume can be adjusted
based on the filling efficiency in accordance with the teachings
described herein. For example, the filling efficiency may comprise
approximately 90%, such that the first portion comprises
approximately 29 uL contained in the chamber of the reservoir
container and the second portion comprises approximately 21 uL
passed through the device for the 50 uL of Lucentis.TM. injected
into the therapeutic device. The initial concentration of
Lucentis.TM. in the vitreous humor corresponds to about 45 ug/mL
immediately following injection into the reservoir device. The
concentration of Lucentis.TM. in the vitreous humor decreases to
about 4 ug/mL at 90 days. A second 50 uL injection of Lucentis.TM.
approximately 90 days after the first injection increases the
concentration to about 50 ug/mL. The concentration of Lucentis.TM.
in the vitreous humor decreases to about 4 ug/mL at 180 days after
the first injection and 90 days after the second injection. These
calculations show that the concentration of Lucentis.TM. can be
continuously maintained above a minimum inhibitory concentration of
about 4 ug per ml with the 50 uL injection into the device.
Additional injections can be made every 120 days for several years
to deliver the therapeutic agent to treat the patient. The
injections can be made more frequently or less frequently,
depending upon the minimum inhibitory concentration, the release
rate profile, and the discretion of the treating physician.
[0519] FIG. 19D shows determined concentrations of Lucentis.TM. in
the vitreous humor for a first 50 uL injection into a 50 uL device
and a second 50 uL injection at 90 days. The calculations show that
the 50 uL dosage of the monthly FDA approved bolus injection can be
used to treat the eye for about 90 days, and that the injections
can be repeated to treat the eye, for example at approximately 90
day intervals. The Lucentis.TM. may comprise a predetermined amount
of the commercially available formulation injected into the device.
The filling efficiency of the injection into the device may
comprise less than 100%, and the reservoir volume and injection
volume can be adjusted based on the filling efficiency in
accordance with the teachings described herein. For example, the
filling efficiency may comprise approximately 90%, such that the
first portion comprises approximately 45 uL contained in the
chamber of the reservoir container and the second portion comprises
approximately 5 uL passed through the device for the 50 uL of
Lucentis.TM. injected into the therapeutic device. The initial
concentration of Lucentis.TM. in the vitreous humor corresponds to
about 11 ug/mL immediately following injection into the reservoir
device. The concentration of Lucentis.TM. in the vitreous humor
decreases to about 5.8 ug/mL at 90 days. A second 50 uL injection
of Lucentis.TM. approximately 90 days after the first injection
increases the concentration to about 17 ug/mL. The concentration of
Lucentis.TM. in the vitreous humor decreases to about 5,8 ug/mL at
180 days after the first injection and 90 days after the second
injection. These calculations show that the concentration of
Lucentis.TM. can be continuously maintained above a minimum
inhibitory concentration of about 5 ug per ml with the 50 uL
injection into the device. Additional injections can be made, for
example every 90 days for several years to deliver the therapeutic
agent to treat the patient.
[0520] FIG. 19E shows determined concentrations of Lucentis.TM. in
the vitreous humor for a first 50 uL injection into a 50 uL device
and a second 50 uL injection at 90 days. The calculations show that
the 50 uL dosage of the monthly FDA approved bolus injection can be
used to treat the eye for about 130 days, and that the injections
can be repeated to treat the eye, for example at approximately 120
day intervals. The Lucentis.TM. may comprise a predetermined amount
of the commercially available formulation injected into the device.
The filling efficiency of the injection into the device may
comprise less than 100%, and the reservoir volume and injection
volume can be adjusted based on the filling efficiency in
accordance with the teachings described herein. For example, the
filling efficiency may comprise approximately 90%, such that the
first portion comprises approximately 45 uL contained in the
chamber of the reservoir container and the second portion comprises
approximately 5 uL passed through the device for the 50 uL of
Lucentis.TM. injected into the therapeutic device. The initial
concentration of Lucentis.TM. in the vitreous humor corresponds to
about 11 ug/mL immediately following injection into the reservoir
device. The concentration of Lucentis.TM. in the vitreous humor
decreases to about 4 ug/mL at 133 days. A second 50 uL injection of
Lucentis.TM. approximately 130 days after the first injection
increases the concentration to about 15 ug/mL. Based on these
calculations, the concentration of Lucentis.TM. in the vitreous
humor decreases to about 4 ug/mL at 266 days after the first
injection and 90 days after the second injection. These
calculations show that the concentration of Lucentis.TM. can be
continuously maintained above a minimum inhibitory concentration of
about 4 ug per ml with the 50 uL injection into the device.
Additional injections can be made, for example every 90 days for
several years to deliver the therapeutic agent to treat the
patient.
[0521] Although FIGS. 19B to 19P make reference to injections of
commercially available off the shelf formulations of Lucentis.TM.,
therapeutic device 100 can be similarly configured to release many
formulations of the therapeutic agents as described herein, for
example with reference to Table 1A and the Orange Book of FDA
approved formulations and similar books of approved drugs in many
countries, unions and jurisdictions such as the European Union. For
example, based on the teachings described herein, one can determine
empirically the parameters of therapeutic device 100 so as to tune
the device to receive a injection of a commercially available
formulation corresponding to a monthly bolus injections and release
the injected therapeutic agent with amounts above the minimum
inhibitory concentration for an extended time of at least about two
months, for example, at least about three months, for example, or
about four months, for example.
[0522] FIG. 19F shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 50 uL
device having a release rate index of 0.05. The concentration of
ranibizumab in the vitreous humor peaks at around 9 ug/mL and is at
or above 4 ug/mL for about 145 days. The concentration remains
above about 1 ug/mL for about 300 days. The concentration is about
0.6 ug/mL at 360 days, and can be suitable for treatment with a
single injection up to one year, based on a minimum inhibitory
concentration of about 0.5. The minimum inhibitory concentration
can be determined empirically by a person of ordinary skill in the
art based on the teachings described herein.
[0523] FIG. 19G shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 75 uL
device having a release rate index of 0.05. The concentration of
ranibizumab in the vitreous humor peaks at around 6.5 ug/mL and is
at or above 4 ug/mL for about 140 days. The concentration remains
above about 1 ug/mL for about 360 days.
[0524] FIG. 19H shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 100 uL
device having a release rate index of 0.05. The concentration of
ranibizumab in the vitreous humor peaks at around 5 ug/mL and is at
or above 4 ug/mL for about 116 days. The concentration remains
above about 1 ug/mL for more than 360 days and is about 1.5 ug/mL
at 360 days.
[0525] FIG. 19I shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 125 uL
device having a release rate index of 0.05. The concentration of
ranibizumab in the vitreous humor peaks at around 4.3 ug/mL and
does not equal or exceed 4 ug/mL. The concentration remains above
about 1 ug/mL for more than 360 days and is about 1.5 ug/mL at 360
days.
[0526] FIG. 19J shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 150 uL
device having a release rate index of 0.05. The concentration of
ranibizumab in the vitreous humor peaks at around 3.5 ug/mL and
does not equal or exceed 4 ug/mL. The concentration remains above
about 1 ug/mL for more than 360 days and is about 1.5 ug/mL at 360
days.
[0527] FIG. 19K shows determined concentrations of ranibizumab in
the vitreous humor for a 50 uL Lucentis.TM. injection into a 100 uL
device having a release rate index of 0.1. These determined
concentrations are similar to the determined concentrations of FIG.
19F, and show that the release rate index of the porous structure
can be tuned with the device volume to provide therapeutic
concentration profile for an extended time. For example, by
doubling the volume of the reservoir so as to half the
concentration of therapeutic agent in the vitreous, the release
rate index can be doubled so as to provide a similar therapeutic
concentration profile. The concentration of ranibizumab in the
vitreous humor peaks at around 9 ug/mL and is at or above 4 ug/mL
for about 145 days. The concentration remains above about 1 ug/mL
for about 300 days. The concentration is about 0.6 ug/mL at 360
days.
[0528] FIGS. 19L to 19P show examples of release rate profiles with
125 uL reservoir devices having the RRI vary from about 0.065 to
about 0.105, such that these devices are tuned to receive the 50 uL
injection of Lucentis.TM. and provide sustained release above a
minimum inhibitory concentration for at least about 180 days. These
calculations used a drug half life in the vitreous of 9 days to
determine the profiles and 100% efficiency of the injection.
[0529] FIG. 19L shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.105. The concentration of ranibizumab in the vitreous at
180 days is about 3.128 ug/mL.
[0530] FIG. 19M shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.095. The concentration of ranibizumab in the vitreous at
180 days is about 3.174 ug/mL.
[0531] FIG. 19N shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.085. The concentration of ranibizumab in the vitreous at
180 days is about 3.185 ug/mL.
[0532] FIG. 190 shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.075. The concentration of ranibizumab in the vitreous at
180 days is about 3.152 ug/mL.
[0533] FIG. 19P shows determined concentration profiles of
ranibizumab in the vitreous humor for a 50 uL Lucentis.TM.
injection into a 125 uL reservoir device having a release rate
index of 0.065. The concentration of ranibizumab in the vitreous at
180 days is about 3.065 ug/mL.
[0534] The optimal RRI for the concentration of ranibizumab at 180
days for a reservoir volume of 125 uL and a 50 uL injection of
Lucentis.TM. can be calculated based on the equations as described
herein, and is about 0.085. Although the optimal value is 0.085,
the above graphs show that the reservoir and release rate index can
be tuned to provide therapeutic amounts of ranibizumab above a
minimum inhibitory concentration of 3 ug/mL with many values of the
RRI and reservoir volume, for example values within about +/-30% to
+/-50% of the optimal values for the predetermined quantity of
Lucentis.TM. formulation.
[0535] Table 4E shows values of parameters used to determine the
ranibizumab concentration profiles as in FIGS. 19K to 19P.
TABLE-US-00015 TABLE 4E Diffusion coeff (cm2/s) 1.0E-06 Initial
Loading (ug/mL) 10000 Reservoir Vol (ml) 0.125 PA/TL (mm) varied
Half-life (days) 9 Rate constant, k (1/day) 0.077 Vitreous vol (ml)
4.5 Volume injected (mL) 0.05 Time step (days) 0.1 Time between
refills (days) 180 Refill Efficiency 100%
[0536] The therapeutic concentration profiles of examples of FIGS.
19B to 19P were determined with a nine day half-life of the drug in
the vitreous humor of the human eye. The therapeutic concentration
profiles can be scaled in accordance with the half life of the
therapeutic agent in the eye. For example, with an eighteen day
half life, the concentration in these examples will be
approximately twice the values shown in the graph at the extended
times, and with a 4.5 day half-life, the concentrations will be
approximately half the values shown with the extended times. As an
example, a drug half life of eighteen days instead of nine days
will correspond to a concentration of about 1.4 ug/mL at 360 days
instead of about 0.6 ug/mL as shown in FIGS. 19F and 19K. This
scaling of the concentration profile based on drug half life in the
vitreous can be used to tune the volume and sustained release
structures of the therapeutic device, for example in combination
with the minimum inhibitory concentration. Although the above
examples were calculated for Lucentis.TM., similar calculations can
be performed for therapeutic agents and formulations as described
herein, for example as described herein with reference to Table
1A.
[0537] Based on the teachings described herein, a person of
ordinary skill in the art can determine the release rate index and
volume of the therapeutic agent based on the volume of formulation
injected into the device and minimum inhibitory concentration. This
tuning of the device volume and release rate index based on the
volume of formulation injected can produce unexpected results. For
example, with a clinically beneficial minimum inhibitory
concentration of about 4 ug/mL, a single bolus injection
corresponding to a one month injection can provide a therapeutic
benefit for an unexpected three or more months, such as four
months. Also, for a clinically beneficial minimum inhibitory
concentration of at least about 1.5 ug/mL, a single bolus injection
corresponding to a one month injection can provide a therapeutic
benefit for an unexpected twelve or more months. The clinically
beneficial minimum inhibitory concentration can be determined
empirically based on clinical studies as described herein.
[0538] Although the examples of FIGS. 19F to 19K assumed a filling
efficiency of one hundred percent, a person of ordinary skill in
the art based on the teachings as described herein can determine
the release rate profiles for filling efficiencies less than 100%,
for example with 90% filling efficiency as shown above. Such
filling efficiencies can be achieved with injector apparatus and
needles as described herein, for example with reference to FIGS. 7,
7A, 7A1 and 7A2.
[0539] FIG. 19Q shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL concentrated Lucentis.TM. (40 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about nine days. These data show that an injection of 10 uL of
concentrated (40 mg/mL) Lucentis.TM. into a 10 uL reservoir device
can maintain the concentration of Lucentis.TM. above at least about
2 ug/mL for at least about 180 days when the half life of
Lucentis.TM. in the vitreous is at least about nine days, and that
the device can provide therapeutic concentrations for an extended
time of at least about 180 days when the minimum inhibitory
concentration comprises no more than about 2 ug/mL.
[0540] FIG. 19R shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL concentrated Lucentis.TM. (40 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about five days. These data show that an injection of 10 uL of
concentrated (40 mg/mL) Lucentis .TM. into a 10 uL reservoir device
can maintain the concentration of Lucentis .TM. above at least
about 1 ug/mL for at least about 180 days when the half life of
Lucentis.TM. in the vitreous is at least about five days, and that
the device can provide therapeutic concentrations for an extended
time of at least about 180 days when the minimum inhibitory
concentration comprises no more than about 1 ug/mL.
[0541] FIG. 19S shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL standard Lucentis.TM. (10 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about nine days. These data show that an injection of 10 uL of
standard commercially available (10 mg/mL) Lucentis.TM. into a 10
uL reservoir device can maintain the concentration of Lucentis.TM.
above at least about 0.5 ug/mL for at least about 180 days when the
half life of Lucentis .TM. in the vitreous is at least about nine
days, and that the device can provide therapeutic concentrations
for an extended time of at least about 180 days when the minimum
inhibitory concentration comprises no more than about 0.5
ug/mL.
[0542] FIG. 19T shows determined concentrations of ranibizumab in
the vitreous humor for a 10 uL standard Lucentis.TM. (10 mg/mL)
injection into a 10 uL device having a release rate index of 0.01
and in which the ranibizumab has a half life in the vitreous humor
of about five days. These data show that an injection of 10 uL of
standard commercially available (10 mg/mL) Lucentis.TM. into a 10
uL reservoir device can maintain the concentration of Lucentis .TM.
above at least about 0.25 ug/mL for at least about 180 days when
the half life of Lucentis .TM. in the vitreous is at least about
five days, and that the device can provide therapeutic
concentrations for an extended time of at least about 180 days when
the minimum inhibitory concentration comprises no more than about
0.25 ug/mL.
Example 10: Calculations of Target Device Characteristics for a
Device Releasing Drug From a Suspension
[0543] Triamcinolone acetonide is a corticosteroid used to treat
uveitis and other diseases involving ocular inflammation. A 4 mg
intravitreal injection of a suspension of triamcinolone acetonide
may be administered to patients unresponsive to topical
corticosteroids. Calculations as described herein were performed to
determine the characteristics of a device that would release
therapeutic amounts for an extended period of time.
[0544] Consider a device with 10 uL reservoir volume loaded with
0.4 mg using a commercial drug product (40 mg/mL triamcinolone
acetonide). Calculations were performed using a value of 19 ug/mL
for the solubility of triamcinolone acetonide measured at
37.degree. C. in 0.2 M potassium chloride and a diffusion
coefficient of 5 e-6 cm.sup.2/s representative of a small molecule.
The target release rate is 1 ug/day based upon published clinical
data. As an example, consider the 0.2 media grade stainless steel
characterized in Example 8 with P/F=0.12 and a thickness of 0.5 mm.
Using these values, the calculations suggest that therapeutic
release rates could be achieved with a device containing a porous
cylinder with an area of 5 mm.sup.2. This could be achieved with a
cylindrical device having an inner diameter of 2 mm and a length of
porous tubing of 1 mm. Alternatively, the end of the device could
be a porous cup with height of 0.8 mm (0.5 mm thick porous face
plus 0.3 mm length) of porous tubing.
[0545] Assuming a typical value of 3 hours for the half-life of a
small molecule in the vitreous, these calculations suggest the
device will achieve a steady state triamcinolone acetonide vitreous
concentration of 0.12 ug/mL.
Example 11: Calculation of Release Rate Profile for a Therapeutic
Agent Suspension Disposed in the Reservoir and Released through the
Porous Frit Structure
[0546] FIG. 20 shows a calculated time release profile of a
therapeutic agent suspension in a reservoir as in Example 10.
Triamcinolone Acetonide concentrations in human vitreous were
determined for a 10 uL device with RRI of 1.2 mm and shown. The
calculations were based on the equations shown above for the
suspension. The profile was generated with numerical simulation.
Assuming a constant delivery rate of 1 ug/day starting
instantaneously at T=0, the concentration in the vitreous of a
human eye can reach within 99% of the steady state value in 1 day.
At the other end of the drug release profile, the simulation shows
the vitreous concentration when substantially all of the solid drug
is gone; more than 99% of the dissolved drug is delivered within a
day.
[0547] Assuming a typical value of 3 hours for the half-life of a
small molecule in the vitreous, these calculations indicate that
the device will achieve a substantially steady state triamcinolone
acetonide vitreous concentration of 0.12 ug/mL in the rabbit or
monkey (vitreous volume of 1.5 mL) or 0.04 ug/mL in the human eye
(vitreous volume of 4.5 mL). The steady state vitreous
concentration are maintained until there is no longer solid
triamcinolone acetonide of the suspension in the reservoir. As
shown in FIG. 20, a device with a 10 uL reservoir volume and
Release Rate Index of 1.2 mm can produce substantially constant
drug concentration amounts in the human vitreous for approx. 400
days. Additional experimental and clinical studies based on the
teachings described herein can be conducted to determine the
release rate profile in situ in human patients, and the drug
reservoir volume and release rate index configured appropriately
for therapeutic benefit for a target time of drug release. The
substantially constant drug concentration amounts can provide
substantial therapy and decrease side effects. Similar studies can
be conducted with many suspensions of many therapeutic agents as
described herein, for example suspensions of corticosteroids and
analogues thereof as described herein.
Example 12: Measured of Release Rate Profiles for Avastin.TM.
through the Porous Frit Structures Coupled to Reservoirs of
Different Sizes and Dependence of Release Rate Profile on Reservoir
Size
[0548] FIG. 21 shows a release rate profiles of therapeutic devices
comprising substantially similar porous frit structures and a 16 uL
reservoir and a 33 uL reservoir. The release rate index of each
frit was approximately 0.02. The release rate for two therapeutic
devices each comprising a 16 uL reservoir and two therapeutic
devices each comprising a 33 uL reservoir are shown. The device
comprising the 33 uL reservoir released the Avastin.TM. at
approximately twice the rate of the device comprising 16 uL
reservoir. These measured data show that the release rate index and
reservoir size can determine the release rate profile, such that
the release rate index and reservoir can be configured to release
the therapeutic agent for an extended time.
[0549] First Study: The data were measured with a 16 uL volume
reservoir as follows: 25 mg/mL Avastin.TM.; Frit #2
(0.031.times.0.049'', media grade 0.2 um, 316L SS, Mott
Corporation); Substantially similar materials as Example 8 above
(Teflon heat shrink tubing and silicone septum); 37C; Data is
truncated when one of two replicates formed a bubble. See data in
Table 5A below.
[0550] Second Study: The data were measured with a 33 uL reservoir
as follows: 25 mg/mL Avastin.TM.; Frit #2 (0.031.times.0.049'',
media grade 0.2 um, 316L SS, Mott Corporation); Machined from solid
beading, closed with a metal rod; 37C; Data is truncated when one
of two replicates formed a bubble.
TABLE-US-00016 TABLE 5A Measured Release of Avastin .TM. and RRI.
Volume (uL) Device RRI (mm) SS (ug/day)2 33 1 0.015 0.35 33 2 0.018
0.16 16 1 0.018 0.05 16 2 0.022 0.06 Mean 0.018 % CV 16%
[0551] SS is the average of the squared difference between
predicted and measured rates, and % CV refers to the coefficient of
variation, a known statistical parameter.
Example 13: Measured Release Rate Profiles for Avastin.TM. through
the Porous Frit Structures
[0552] FIG. 22A shows cumulative release for Avastin.TM. with
porous frit structures having a thickness of 0.049''. The
experiments used: 25 mg/mL Avastin.TM.; Frit #2
(0.031.times.0.049'', media grade 0.2 um, 316L SS, Mott
Corporation); Machined polycarbonate surrogate with screw;
Reservoir Volume 37 uL;37C. The device number and corresponding
RRI's for each tested device are listed in Table 5B below. The
determined RRI based on measurements is 0.02, consistent with the
model for release of the therapeutic agent as described herein.
Although some variability is noted with regards to the measured RRI
for each test device, the RRI for each device can be used to
determine the release of the therapeutic agent, and the porous
structure can be further characterized with gas flow as described
herein to determine the RRI prior to placement in the patient.
TABLE-US-00017 TABLE 5B Device RRI (mm) SS (ug/day)2 1 0.029 26.0 2
0.027 8.5 5 0.018 3.7 30 0.013 0.1 31 0.013 0.1 32 0.015 0.7 33
0.022 30.5 Mean 0.020 % CV 34%
[0553] FIG. 22B1 shows cumulative release for Avastin.TM. with
porous frit structures having a thickness of 0.029''. The
experiments used: 25 mg/mL Avastin.TM.; Frit #3
(0.038.times.0.029'', media grade 0.2 um, 316L SS, Mott
Corporation); Machined polycarbonate surrogate with screw;
Reservoir Volume 37 uL; 37C. The device number and corresponding
RRI's for each tested device are listed in Table 5C below. The
determined RRI based on measurements is 0.034, consistent with the
model for release of the therapeutic agent as described herein.
Although some variability is noted with regards to the measured RRI
for each test device, the RRI for each device can be used to
determine the release of the therapeutic agent, and the porous
structure can be further characterized with gas flow as described
herein to determine the RRI prior to placement in the patient.
TABLE-US-00018 TABLE 5C Device RRI (mm) SS (ug/day)2 9 0.033 0.7 10
0.044 10.8 13 0.030 0.7 27 0.043 15.8 28 0.033 2.6 34 0.030 0.9 35
0.027 0.3 36 0.034 5.5 Mean 0.034 % CV 19%
[0554] Table 5D shows an update to Table 5B showing experimental
results for up to 130 days. Similarly, Table 5E is an update to
Table 5C. In both cases, the RRI was determined by fitting the rate
data from each device. For the analysis of data up to 130 days, the
first data point is excluded from the fit because the model assumes
the maximum delivery rate occurs at time zero while there is some
startup time often associated with measured release profiles. The
startup time may be related to the time it takes to displace all of
the air in the frit. Use of different techniques to displace the
air in the frit may reduce the startup time.
[0555] This early data has some noise that appears to be related to
experimental issues such as contamination from excess protein that
is present on the screw from filling the device and was not
completely rinsed off at the start of the experiment. The
contamination appears to occur randomly as receiver liquid may
rinse off the protein while transferring the device from vial to
vial at some time points but not others. A more accurate assessment
of RRI can be obtained by using devices that had fewer or no
outliers, as indicated by low values of SS. When this is done, the
RRIs from Table 5D and 5E are 0.014 and 0.030 mm, respectively.
Similar values for RRI are obtained from data up to 45 days and
data up to 130 days, supporting the validity of the model.
TABLE-US-00019 TABLE 5D Up to 45 Days Up to 130 Days SS SS Device
RRI (mm) (ug/day){circumflex over ( )}2 RRI (mm)
(ug/day){circumflex over ( )}2 1 0.029 26.0 0.032 13.7 2 0.027 8.5
0.028 5.5 5 0.018 3.7 0.014 1.7 30 0.013 0.1 0.021 4.8 31 0.013 0.1
0.022 9.3 32 0.015 0.7 0.023 3.4 33 0.022 30.5 0.028 16.4 Mean
0.020 0.024 % CV 34% 24% Mean for 0.014 0.014 SS < 2
TABLE-US-00020 TABLE 5E Up to 45 Days Up to 130 Days SS SS Device
RRI (mm) (ug/day){circumflex over ( )}2 RRI (mm)
(ug/day){circumflex over ( )}2 9 0.033 0.7 0.034 4.4 10 0.044 10.8
0.034 2.0 13 0.030 0.7 0.044 11.6 27 0.043 15.8 0.045 6.8 28 0.033
2.6 0.031 0.5 34 0.030 0.9 0.030 0.7 35 0.027 0.3 0.029 1.3 36
0.034 5.5 0.034 5.9 Mean 0.034 0.035 % CV 19% 17% Mean for 0.030
0.030 SS < 2
[0556] FIG. 22B2 shows rate of release for Avastin.TM. with porous
frit structures having a thickness of 0.029'' as in FIG. 22B1. The
rate of release can be determined from the measurements and the
cumulative release. The outliers in this data can be related to
measurement error, such as contamination that provides a signal in
the mBCA protein assay.
[0557] FIG. 23A shows cumulative release for Avastin.TM. with a
reservoir volume of 20 uL. The experiment used: 25 mg/mL
Avastin.TM.; Frit #6 (0.038.times.0.029'', media grade 0.2 um, 316L
SS, Mott Corporation); Machined polycarbonate surrogate with screw;
37C. The determined RRI based on measurements is 0.05 mm,
consistent with the model for release of the therapeutic agent as
described herein.
[0558] FIG. 23A-1 shows cumulative release to about 90 days for
Avastin.TM. with a reservoir volume of 20 uL as in FIG. 23A. The
RRI of 0.053 mm corresponds substantially to the RRI of 0.05 of
FIG. 23 and demonstrates stability of the release of therapeutic
agent through the porous structure.
[0559] FIG. 23B shows rate of release as in FIG. 23A. The release
rate data show a rate of release from about 5 ug per day to about 8
ug per day. Although the initial release rate at the first day is
slightly lower than subsequent rates, the rate of release is
sufficiently high to provide therapeutic effect in accordance with
the drug release model. Although there can be an initial period of
about a few days for the release rate profile to develop, possibly
related to wetting of the interconnecting channels of the porous
structure, the release rate profile corresponds substantially to
the release rate index (RRI) of 0.05. Based on the teachings
described herein, a person of ordinary skill in the art could
determine the release rate profile with additional data for an
extended time of at least about one month, for example at least
about three months, six months or more, so as to determine the
release rate profile for an extended time.
[0560] FIG. 23B-1 shows rate of release as in FIG. 23A-1.
[0561] FIG. 24A shows cumulative release for Avastin.TM. with a 0.1
media grade porous frit structure. This experiment used: 25 mg/mL
Avastin.TM.; Frit #5 (0.038.times.0.029'', media grade 0.1 um, 316L
SS, Mott Corporation); Machined polycarbonate surrogate with screw;
Reservoir Volume 20 uL; 37C. The determined RRI based on
measurements is 0.03, consistent with the model for release of the
therapeutic agent as described herein.
[0562] FIG. 24A-1 shows cumulative to about 90 days release for
Avastin.TM. with a 0.1 media grade porous frit structure as in FIG.
24A. The release rate of 0.038 mm corresponds substantially to the
release rate of 0.03 of FIG. 24A and demonstrates the stability of
release of the therapeutic agent through the porous structure.
[0563] FIG. 24B shows rate of release as in FIG. 24A. The release
rate data show a rate of release from about 2 ug per day to about 6
ug per day. Although the initial release rate at the first day is
slightly lower than subsequent rates, the rate of release is
sufficiently high to provide therapeutic effect in accordance with
the drug release model. Although there can be an initial period of
a few days for the release rate profile to develop, possibly
related to wetting of the interconnecting channels of the porous
structure, the release rate profile corresponds substantially to
the release rate index (RRI) of 0.03. Based on the teachings
described herein, a person of ordinary skill in the art could
determine the release rate profile with additional data for an
extended time of at least about one month, for example at least
about three months, six months or more, so as to determine the
release rate profile for an extended time.
[0564] FIG. 24B-1 shows rate of release as in FIG. 24A-1.
Example 14: Determination of Therapeutic Device Size and Lifetime
based on Minimum Inhibitory Concentration In Vivo of Therapeutic
Agent
[0565] Numerical calculations were performed to determine
therapeutic device sizes, release rate profiles and expected
therapeutic agent concentration in the reservoir. The concentration
in the reservoir may correspond to the useful lifetime of the
device, or time between injections of therapeutic agent into the
reservoir or other replacement of the therapeutic agent.
[0566] Table 6A shows the number days of therapeutic agent is
released from the device with concentration amounts at or above the
MIC. These number of days correspond to an effective lifetime of
the device or effective time between injections into the device.
The calculations show the number of days of the extended time
release based the RRI and MIC for a 20 uL reservoir volume having a
drug concentration disposed therein of 10 mg/ml. The RRI ranged
from 0.01 to 0.1 and the MIC ranged from 0.1 to 10, and can be
determined with experimental and clinical studies as described
herein. The half-life of therapeutic agent in the vitreous was
modeled as 9 days, based on human data. The Cmax indicates the
maximum concentration of therapeutic agent in the vitreous humor,
for example within a few days of placement or injection of the
therapeutic agent in the device These data indicate that the device
can maintain the concentration of therapeutic agent for about 756
days, 385 days, 224 days, and 62 day for MIC's of 0.1, 0.5, 1, 2
and 4 ug/ml, respectively. For example, the therapeutic agent may
comprise Lucentis.TM. having an MIC of about 0.5 and the device may
maintain therapeutic concentrations of the agent for one year.
These numerical data also show a concentration of therapeutic agent
released from the device within a range of the current clinical
bolus injections. For example, the Cmax ranges from 2.1 to 11.9
based on the RRI from 0.01 to 0.1 respectively, such that the
maximum release of therapeutic agent such as Lucentis.TM. is within
a safe range for the patient.
[0567] A person of ordinary skill in the art can conduct
experiments to determine the stability of the therapeutic agent
such as Lucentis.TM. in the reservoir, and adjust the size of the
reservoir, time between injections or removal. The therapeutic
agent can be selected and formulated so as to comprise a stability
suitable for use in the therapeutic device.
TABLE-US-00021 TABLE 6A Calculations for Time (days) above MIC (20
.mu.L Reservoir Volume, T1/2 = 9 days, Drug Conc. in Reservoir = 10
mg/ml) Cmax MIC (.mu.g/ml) RRI (.mu.g/ml) 0.1 0.5 1 2 4 7 10 0.01
2.1 756 385 224 62 0 0 0 0.02 3.8 467 280 200 119 0 0 0 0.04 6.5
281 188 148 108 66 0 0 0.06 8.6 209 147 120 93 65 40 0 0.08 10.4
170 124 103 83 61 42 14 0.1 11.9 146 109 92 75 58 42 30
[0568] Table 6B. Shows calculations for time (days) above the MIC
for a therapeutic device comprising a 20 .mu.L Volume, Vitreous
T1/2=9 days, and Drug Conc. in Reservoir=40 mg/ml. The embodiments
of Table 6B include similar components to the embodiments of Table
6A and the improved time above MIC achieved with concentration of
40 mg/ml. For example, the time above the MIC can be 1079, 706,
546, 385, 225, 95, for MIC's of 0.1 0.5, 1, 2, 4, and 7 ug/ml,
respectively. For example, the therapeutic agent may comprise
Lucentis.TM. having an MIC of about 0.5 and the device may maintain
therapeutic concentrations of the therapeutic agent for about 2
years. These numerical data also show a concentration of
therapeutic agent released from the device within a range of the
current clinical bolus injections. For example, the Cmax ranges
from 8.4 to 47.6 based on the RRI from 0.01 to 0.1 respectively,
such that the maximum release of therapeutic agent such as
Lucentis.TM. is within a safe range for the patient.
[0569] A person of ordinary skill in the art can conduct
experiments to determine the stability of the therapeutic agent
such as Lucentis.TM. in the reservoir, and adjust the size of the
reservoir, time between injections or removal. The therapeutic
agent can be selected and formulated so as to comprise a stability
suitable for use in the therapeutic device.
TABLE-US-00022 TABLE 6B Calculations for Time (days) above MIC (20
.mu.L Volume, T1/2 = 9 days, Drug Conc. in Reservoir = 40 mg/ml)
Cmax MIC (.mu.g/ml) RRI (.mu.g/ml) 0.1 0.5 1 2 4 7 10 0.01 8.4 1079
706 546 385 225 95 0 0.02 15.1 626 440 360 280 200 135 93 0.04 25.9
361 268 228 188 148 115 94 0.06 34.4 262 200 174 147 120 98 84 0.08
41.5 210 164 144 124 103 87 76 0.1 47.6 179 141 125 109 92 79
70
[0570] Table 6C. Shows calculations for time (days) above the MIC
for a therapeutic device comprising a 50 .mu.L Volume, Vitreous
T1/2=9 days, and Drug Conc. in Reservoir=40 mg/ml. The embodiments
of Table 6B include similar components to the embodiments of Table
6A and the improved time above MIC achieved with concentration of
40 mg/ml. For example, the time above the MIC can be 2706, 1737,
1347, 944, 542 and 218, for MIC's of 0.1 0.5, 1, 2, 4, and 7 ug/ml,
respectively. For example, the therapeutic agent may comprise
Lucentis.TM. having an MIC of about 0.5 and the device may maintain
therapeutic concentrations of the therapeutic agent for more than
about 2 years. These numerical data also show a concentration of
therapeutic agent released from the device within a range of the
current clinical bolus injections. For example, the Cmax ranges
from 9.1 to 64.7 ug/ml based on the RRI from 0.01 to 0.1
respectively, such that the maximum release of therapeutic agent
such as Lucentis.TM. is within a safe range for the patient.
[0571] A person of ordinary skill in the art can conduct
experiments to determine the stability of the therapeutic agent
such as Lucentis.TM. in the reservoir, and adjust the size of the
reservoir, time between injections or removal. The therapeutic
agent can be selected and formulated so as to comprise a stability
suitable for use in the therapeutic device.
TABLE-US-00023 TABLE 6C Calculations for Time (days) above MIC (50
.mu.L Volume, T1/2 = 9 days, Drug Conc. in Reservoir = 40 mg/ml)
Cmax MIC (.mu.g/ml) RRI (.mu.g/ml) 0.1 0.5 1 2 4 7 10 0.01 9.1 2706
1737 1347 944 542 218 0 0.02 17.2 1560 1082 880 679 478 316 213
0.04 31.5 887 648 547 446 346 265 213 0.06 43.8 635 476 408 341 274
220 186 0.08 54.8 501 381 331 281 230 190 164 0.1 64.7 417 321 281
240 200 168 147
[0572] The examples shown in Tables 6A to 6C can be modified by one
of ordinary skill in the art in many ways based on the teachings
described herein. For example, the 50 uL reservoir may comprise an
expanded configuration of the reservoir after injection of the
therapeutic device. The reservoir and/or quantity of therapeutic
agent can be adjusted so as to provide release for a desired
extended time.
[0573] The porous frit structure as described herein can be used
with many therapeutic agents, and may limit release of therapeutic
agent that has degraded so as to form a particulate, for example.
Work in relation to embodiments suggests that at least some
therapeutic agents can degrade so as to form a particulate and that
the particulate comprising degraded therapeutic agent may have an
undesired effect on the patient, and the porous frit structure as
described herein may at least partially filter such particulate so
as to inhibit potential side effects of degraded therapeutic
agent.
[0574] Table 6D shows examples of sizes of therapeutic devices that
can be constructed in accordance with the teachings described
herein, so as to provide a suitable volume of the drug reservoir
within the container and such devices may comprise many lengths,
widths and structures as described herein. For example the frit
outside diameter (hereinafter "OD") can be configured in many ways
and may comprise about 1 mm, for example, or about 0.5 mm. The
length of the frit (thickness) may comprise about 1 mm. The volume
of the frit can be, for example, about 0.785 uL, or about 0.196 uL,
for example. The volume of the reservoir can be from about 0.4 uL
to about 160 uL, for example. The volume of the therapeutic device
can be from about 0.6 uL to about 157 uL, and can be positioned in
many ways, for example with a lumen and may comprise a
substantially fixed volume reservoir or an expandable reservoir.
The cross sectional width of the device may correspond to many
sizes, for example many radii, and the radius can be within a range
from about 0.3 mm to about 3.5 mm, for example. The cross-section
width and corresponding diameters of the device can be within a
range from about 0.6 mm to about 7 mm. The length of the device,
including the porous structure, container and retention structure
can be many sizes and can be within a range from about 2 mm to
about 4 mm, for example. The device may comprise a substantially
fixed diameter, or alternatively can be expandable, and may
comprise fixed or expandable retention structures, as described
herein.
TABLE-US-00024 TABLE 6D Frit OD (mm) 1 0.5 Frit Length (mm) 1 1
Frit Vol. (uL) 0.785 0.19625 Vol Res (uL) 0.4 2 4 8 16 27 31 39 63
110 157 Vol Frit (uL) 0.19625 0.19625 0.785 0.785 0.785 0.785 0.785
0.785 0.785 0.785 0.785 Vol Device (uL) 0.59625 2.19625 4.785 8.785
16.785 27.785 31.785 39.785 63.785 110.785 157.785 Radius squared
0.09 0.3 0.4 0.7 1.3 2.2 2.5 3.2 5.1 8.8 12.6 Radius (mm) 0.3 0.5
0.6 0.8 1.2 1.5 1.6 1.8 2.3 3.0 3.5 OD (mm) 0.6(4) 1.1(3) 1.2(3)
1.7(3) 2.3(3) 3.0(2) 3.2(2) 3.6(2) 4.5(2) 5.9(2) 7.1(2) Dev Length
(mm) 2.0(6) 2.5(5) 4.0(1) 4.0(1) 4.0(1) 4.0(1) 4.0(1) 4.0(1) 4.0(1)
4.0(1) 4.0(1) (1)Fixed penetration upper limit (2)May use non
simple cylinder design to decrease incision length, for example
expandable reservoir (3)OD accommodates 1 mm diameter porous frit
structure and satisfies incision length limit (4)Device OD may use
a smaller porous frit structure (5)Length reduced to drive OD to
accommodate porous frit structure (6)Length reduced to drive OD to
accommodate porous frit structure, and Device OD may use smaller
frit
Example 15A: Calculation and Measurement of Small Release Rate
Profiles as a Model for a Therapeutic Agent Released through the
Porous Frit Structure
[0575] Studies of the release of fluorescein from reservoirs
through porous frit structures were conducted so as to determine
the release of small molecule drugs through the porous frit
structure. The fluorescein model shows that the porous frit
structures and reservoirs as described herein are suitable for use
with small molecule drug deliver. The release profiles of
Avastin.TM., Lucentis.TM. and BSA in conjunction with the
fluorescein data show that the porous frit structures and
reservoirs can be used for sustained release of many drugs,
molecules and therapeutic agents of many molecular weights and
sizes.
[0576] FIG. 25A shows cumulative release for fluorescein through a
0.2 media grade porous frit structure. The experiment used: 2 mg/mL
Fluorescein sodium; Frit #2 (0.031.times.0.049'', media grade 0.2
um, 316L SS, Mott Corporation); Machined polycarbonate surrogate
with screw; 37C. The fluorescein samples were assayed by UV
absorbance at 492 nm with a plate reader. The determined RRI based
on measurements is 0.02, consistent with the model for release of
the therapeutic agents as described herein.
[0577] FIG. 25A-1 shows cumulative release to about 90 days for
fluorescein through a 0.2 media grade porous frit structure as in
FIG. 25A. The mean RRI based upon the first four data points was
0.02 mm. The mean RRI to release for 90 days (excluding the first
point) is 0.026 mm. These data show stability of the rate of
release and that the porous frit structure can be used for small
molecule delivery or large molecule delivery, or combinations
thereof.
[0578] FIG. 25B shows rate of release as in FIG. 25A. The release
rate data show a rate of release from about 1.0 ug per day to about
1.8 ug per day. Although the initial release rate at the first day
is slightly lower than subsequent rates, the rate of release is
sufficiently high to provide therapeutic effect in accordance with
the drug release model. Although there can be an initial period of
about a day for the release rate profile to develop, possibly
related to wetting of the interconnecting channels of the porous
structure, the release rate profile corresponds substantially to
the release rate index (RRI) of 0.02. Based on the teachings
described herein, a person of ordinary skill in the art could
determine the release rate profile with additional data for an
extended time of at least about one month, for example at least
about three months, six months or more, so as to determine the
release rate profile for an extended time.
[0579] FIG. 25B-1 shows rate of release as in FIG. 25A-1.
Example 15B: Measured Release Rate Profiles for Lucentis.TM.
through the Porous Frit Structures
[0580] The experiments used: 10 mg/mL Lucentis.TM.; Machined
poly(methyl methacrylate) surrogate with screw; and a Reservoir
Volume 30 uL; 37C. All porous frit structures are 316L SS, Mott
Corporation. Data shown are measured data from all devices except
for a few samples that showed either bubble growth or low receiver
volume.
[0581] Table 6E shows results for 39 out of 48 devices were
included in the table and graphs shown below. The data from the in
vitro studies shown in Table 6E show that Lucentis.TM. can be
delivered with the device having porous frit structure. The
diameter ranged from 0.031'' to 0.038'', and the length ranged from
0.029 to 0.049. The media grade ranged from 0.1 to 0.3, and the RRI
ranged from 0.014 to 0.090. The data show very low variability
suitable in in vivo human treatment, with the % CV below 10% in all
insances, and less than 3% for four of five device configurations
measured.
[0582] Although some of the measurements were excluded, this
exclusion is appropriate and associated with in vitro testing
conditions that differ substantially from the in vivo model. Five
devices were excluded due to bubble growth (10%), and four were
excluded due to receiver volume issues at one timepoint for that
device (8%). The latter can be an experimental error associated
with the volume of the receiver below the assumed value due to
evaporation from inadequately sealed vials or due to pipetting
error. In some instances the in vitro experimental test apparatus
can be sensitive to bubble formation that may differ substantially
from the in vivo model as the living eye can resorb oxygen from the
therapeutic devices. Bubbles can form as receiver fluid is heated
to 37.degree. C. and gas concentrations are greater than their
solubilities at 37.degree. C. To minimize the occurrence of bubble
formation, receiver solutions were degassed before insertion of the
devices. These experimental in vitro studies suggest that degassing
of samples can be helpful with the in vitro assays.
TABLE-US-00025 TABLE 6E Frit Dimensions Media Grade RRI Number of
Dia Length (.mu.m) (mm) % CV Replicates 0.038'' 0.029'' 0.3 0.090
2.1% 6 0.038'' 0.029'' 0.2 0.061 2.8% 14 0.038'' 0.029'' 0.1 0.039
2.3% 5 0.031'' 0.049'' 0.2 0.021 9.9% 12 0.031'' 0.049'' 0.1 0.014
2.5% 2
[0583] FIG. 25C shows cumulative release to about thirty days for
Lucentis.TM. through a 0.2 media grade porous frit structure having
a diameter of 0.038 in and a length (thickness) of 0.029,
corresponding to a release rate of 0.061 as shown in the second row
of Table 6E.
[0584] FIG. 25D shows rates of release of the devices as in FIG.
25C.
[0585] FIG. 25E shows cumulative release to about thirty days for
Lucentis.TM. for 30 uL devices having a RRI's from about 0.090 to
about 0.015.
[0586] FIG. 25F shows rates of release of the devices as in FIG.
25E.
[0587] FIG. 25E1 and 25F1 show an update of Lucentis drug release
studies in FIGS. 25E and 25F, respectively, measured up to 6
months. Data for two devices having the fastest releasing RCEs ends
prior to 6 months when the therapeutic agent has been substantially
depleted.
[0588] These above experimentally measured data show stable release
of the Lucentis.TM. for 30 days for a wide range of frit diameters,
thicknesses and media grades consistent with the release rate model
of the porous structure and reservoir as described herein. For
example, the media grade, thickness, diameter and reservoir volume
can be tuned to provide sustained release for a predetermined
period of time above a predetermined targeted minimum inhibitory
concentration. When combined with the Avastin.TM. and Fluorescein
data, these data show that stable release can be achieved for
extended times for many therapeutic agents consistent with the
release model as described herein.
Example 16: Scanning Electron Micrographs of Porous Frit
Structures
[0589] FIGS. 26A and 26B show scanning electron microscope images
from fractured edges of porous frit structures of 0.2 media grade
and 0.5 media grade porous material, respectively. The commercially
available samples were obtained from Mott Corporation and comprised
316L stainless steel. The samples were mechanically fractured so as
to show the porous structure and interconnecting channels within
the material to release the therapeutic agent. The micrograph
images show a plurality of interconnecting channels disposed
between openings of the first surface and openings of the second
surface.
[0590] FIGS. 27A and 27B show scanning electron microscope images
from surfaces of porous frit structures of media grade of 0.2 and
0.5, respectively, from the samples of FIGS. 26A and 26B. The
images show a plurality of openings on the surface connected with
interconnecting channels as in FIGS. 26A and 26B.
Example 17: Porous Frit Structure Mechanical Flow Testing to
Identify Porous Frit Structures Suitable for Use with Therapeutic
Agent Delivery Devices
[0591] The relative characteristics of sample elements can be
determined by subjecting the frit to a number of mechanical tests,
including but not limited to pressure decay and flow. These tests
can be combined with drug release rate information, for example the
RRI, so as to determine the release profile of the devices. These
tests can be used with the porous structure positioned on the
therapeutic device, so as to quantify flow through the porous
structure of the device and determine suitable of the porous
structure. Similar tests can be used to quantify the porous
structure prior to mounting on the therapeutic device. At least
some of the therapeutic devices can be evaluated with the gas flow
of the porous structure mounted on a partially assembled
therapeutic device, for example as a quality control check In some
embodiments, the flow test can be performed on the partially
assembled or substantially assembled therapeutic device prior to
insertion of the therapeutic agent into the reservoir and prior to
insertion into the patient, so as to ensure that the porous
structure is suitable for release of the therapeutic agent and
affixed to the device, for example a support of the therapeutic
device.
[0592] These tests may utilize a variety of working fluids, but
will most likely use a readily available gas such as air or
nitrogen. To date, flow and pressure decay tests have been used to
identify different frit characteristics that may be correlated to
other test results such as chemical or pharmacologic
performance.
Fixturing
[0593] Each of the test methods above may use a mechanical
connection of the test specimen to the test hardware and a number
of techniques have been explored and employed. These fixtures
include a both a means of reliably securing the specimen (such as
heat recoverable tubing, elastic tubing, press fits into relatively
rigid components, etc.) and a means of coupling (such as a Luer,
barbed fitting, quick connect coupling, etc.) that allow convenient
and repeatable attachment to the test hardware.
Test Hardware
[0594] Each of the desired tests can be developed using
commercially available solutions, or by assembling readily
available instrumentation to create a custom test arrangement.
Again, both of these approaches have been evaluated. A working
system will consist of a means for connecting a test specimen, a
controllable source (usually, but not limited to pressure), a
manometer (or other pressure measurement device), and one or more
transducers (pressure, flow, etc.) used to measure the test
conditions and/or gather data for further analysis.
Example 17A. Pressure Decay Test to Identify Porous Structures
Suitable for Use with Therapeutic Drug Delivery Devices
[0595] FIG. 28 shows a pressure decay test and test apparatus for
use with a porous structure so as to identify porous frit
structures suitable for use with therapeutic devices in accordance
with embodiments described herein.
[0596] One method of pressure decay testing is performed with the
hardware shown schematically in FIG. 28. An initial pressure is
applied to the system by an outside source such as a syringe,
compressed air, compressed nitrogen, etc. The manometer may be
configured to display simply the source gage pressure, or the
actual differential pressure across the specimen. One side of the
fixtured specimen is normally open to atmosphere, creating a
pressure which will decay at a rate determined by the properties of
the frit being tested. The instantaneous pressure may be measured
by a pressure transducer that converts and supplies a signal to a
data acquisition module (DAQ) that transfers data to a computer.
The rate of pressure drop is then recorded and can be used for
comparison to the performance of other frits or an acceptability
requirement/specification. This comparison may be made by grossly
comparing the pressure at a given time, or by directly comparing
the output pressure decay curves.
[0597] An example test procedure would pressurize the system too
slightly greater than 400 mmHg as displayed by the manometer. The
computer and DAQ are configured to begin data acquisition as the
pressure drops below 400 mmHg, and a data point is taken
approximately every 0.109 seconds. While the test can be stopped at
any time, it is likely that standard discreet points along the
course of pressure decay data would be selected so as to allow
direct comparison of frit flow performance (e.g. time for decay
from 400 mmHg to 300 mmHg, and from 400 mmHg to 200 mmHg.)
Example 17B. Pressure Decay Test to Identify Porous Structures
Suitable for Use with Therapeutic Drug Delivery Devices
[0598] FIG. 29 shows a pressure flow test and test apparatus
suitable for use with a porous structure so as to identify porous
frit structures suitable for use with therapeutic devices in
accordance with embodiments described herein.
[0599] Using a similar hardware set-up, flow thru the test specimen
can also be characterized. In this test, the source pressure is
constantly regulated to a known pressure and the flow of a working
fluid is allowed to flow thru a mass flow meter and then thru the
fixtured test frit. As in the pressure decay test, the specific
characteristics of the frit determine that rate at which the
working fluid will flow through the system. For additional
accuracy, pressure at the otherwise open end of the fixture test
frit may be regulated to control the backpressure, and therefore
the pressure drop across the specimen.
[0600] Flow testing may have advantages over pressure decay testing
due to the instantaneous nature of the method. Rather than waiting
for the pressure to drop, the flow thru a sample should stabilize
quickly enabling testing of large number of samples to be performed
in rapid fashion.
[0601] In an example test procedure, a regulated compressed
cylinder would supply the system with a constant source pressure of
30 psig and a constant back pressure of 1 psig. The test fluid
would flow through the test frit at a characteristic rate (which is
dependent on the pressure, but is expected to be in the 10-500 sccm
range) as measured by the mass flow meter.
Example 17C: Determination of Therapeutic Release Rate Based on Gas
Flow
[0602] Table 7 shows a table that can be used to determine release
of therapeutic agent, for example the RRI, based on the flow of a
gas such as oxygen or nitrogen through the porous structure. The
flow through the porous structure can be measured with a decay time
of the gas pressure, for example with the flow rate across the
porous structure with a pressure drop across the porous frit
structure, as described herein. The flow rate and RRI can be
determined based on the media grade of the material, for example as
commercially available media grade material available from Mott
Corp. The therapeutic agent can be measured through the porous
structure, or a similar test molecule. The initial measurements
measured the RRI for Avastin.TM. with the porous frit structures
shown. Based on the teachings described herein, a person of
ordinary skill in the art can conduct experiments to determine
empirically the correspondence of flow rate with a gas to the
release rate of the therapeutic agent.
TABLE-US-00026 TABLE 7 Media O.D. Length 300 200 Grade (in.) (in.)
RRI Flow Decay Decay 0.2 0.031 0.049 0.019 106 256 0.2 0.038 0.029
0.034 0.1 0.038 0.029 0.014 81 201 0.2 0.038 0.029 0.033 31 78
[0603] The above partially populated table shows the amount and
nature of frit data that can collected. It is contemplated to use
some form of non-destructive testing (i.e. not drug release
testing) so as to enable: [0604] a) QC receiving inspection testing
of frits [0605] b) QC final device assembly testing
[0606] One of ordinary skill can demonstrate a correlation between
one or more "flow" tests and the actual drug release testing which
relies on diffusion rather than forced gas flow. The data suggests
that flow testing of frits can be both repeatable and falls in line
with expectations.
[0607] Preliminary testing also indicates that the test for the
frit alone can be substantially similar to the frit as an assembled
device.
Example 18: Determination of Minimum In Vivo Inhibitory
Concentration of Lucentis.TM. in Humans
[0608] Although administration of the standard dose of Lucentis.TM.
(500 .mu.g) via direct intravitreal injection has been shown to be
effective in reducing symptoms of patients suffering from wet AMD,
the below clinical studies indicate that a lower concentration can
be used to treat wet AMD. A device as described herein can be used
to treat AMD with a minimum inhibitory concentration in vivo in
human patients (hereinafter "MIC") with a smaller amount than
corresponds to the 500 .mu.g monthly bolus injection. For example,
5 ug Lucentis.TM. injections can be administered so as to obtain a
concentration profiles in situ in humans in accordance with Table
4D and FIG. 19A above.
[0609] The study was designed to detect quickly a positive response
to Lucentis.TM. treatment. A reduction of retinal thickness is an
indicator of positive response to Lucentis.TM. therapy and a marker
of drug effect that can be used to quickly identify a positive
effect of drug treatment. The reduction in retinal thickness
corresponds to subsequent improvement in vision. Hence, the low
dose MIC study assessed the condition of retinal thickness both
before and after patient's exposure to low dose bolus
administration of Lucentis.TM., so as to determine the MIC.
[0610] OCT (Optical Coherence Tomography) imaging was used to
assess the condition of the region of the macula at the back
surface of the treated eye. The OCT technique relies on the
measurement of certain properties of light (e.g. echo time,
intensity of reflection) that has been directed at the area of
study and can measure very small amounts of reflected light.
Because these cellular features are essentially transparent it is
possible to use OCT methodology to generate three dimensional
representations of the area.
[0611] The anatomical region of patients suffering from wet AMD
typically involves disturbances to the structural make-up of the
various cellular layers of the back surface of the eye, notably
including areas of retinal thickening often involving accumulations
of subretinal fluid. In more advanced stages these areas of fluid
accumulation often involve cyst-like formations easily evaluated
via OCT.
[0612] The OCT images generated in the study enabled of various
types of assessments to be made regarding the condition of the
anatomical region of interest. One type of OCT image comprises a
topographic map of the entire region of the macula. This image type
is referred to as the "macular cube". The macular cube OCT images
are typically displayed as color images and in the case of the
macular cube the image provides an indication of overall topography
of the disease/lesion location. These macular cube images were used
identify regions of the macular of interest.
[0613] The regions of interest were analyzed with a two dimensional
representation of the cross section of the retinal wall at one
longitudinal scan location of the OCT image. In these "OCT scan"
images is it possible to interrogate very local areas of interest
more specifically. The OCT scans were carefully selected to
directly compare the thickness and anatomical structure of specific
sites within a lesion, pre and post treatment, for the purpose of
assessing the effect of injected drug including a reduction in
sub-retinal fluid.
[0614] Macular cube images and OCT scan images were measured before
and after Lucentis.TM. treatment for each patient enrolled in the
study. The OCT images were measured the day after injection and at
2-3 days post injection. An ophthalmologist reviewed the OCT images
from the patients enrolled in the study, and patients were
considered to have a responded to Lucentis.TM. treatment when the
OCT scans showed a decrease in size of the lesion from one or more
of the post-injection examinations.
[0615] FIG. 30A-1 shows an example of an OCT macular cube OCT image
used to identify a region of interest (black arrow) and determine
the response to treatment.
[0616] FIGS. 30B-1, 30B-2 and 30B-3 shows an example of a series of
OCT scan images measured at pre-injection, one day post-injection
and one week post-injection, respectively of sections of the region
of interest.
[0617] Table 8 shows the results for 9 patients enrolled in the
study. The patients received doses from 5 to 20 ug, corresponding
to initial Lucentis.TM. concentrations in the vitreous from 1 to 4
ug/ml. Based on the above criteria, a positive response was
identified in all 9 patients. In at least some instances with the 5
um injection, the decrease in size of the lesion was noted
approximately 2-4 days post-op, and the decrease was substantially
attenuated by one week post-op, consistent with the approximately 9
day in vivo half-life of Lucentis.TM.. These data indicated that
the MIC for a sustained release device may be approximately 1 ug
per ml or less. As the therapeutic agent may have a cumulative
effect, the MIC can be lower for a sustained release as described
herein than the bolus injection described with reference to the MIC
study. Further studies can be conducted by one or ordinary skill in
the based on the teachings described herein to determine
empirically the MIC for a sustained release device and cumulative
effect of the drug over the time of release.
TABLE-US-00027 TABLE XX Patient # 1 2 3 4 5 6 7 8 9 Lowest Dose 10
20 20 5 20 5 5 5 5 Administered (.mu.g) Estimated Initial 2 4 4 1 4
1 1 1 1 Drug Conc. in Vitreous (.mu.g/mL) Treatment Yes Yes Yes Yes
Yes Yes Yes Yes Yes Effect Observed?
[0618] FIGS. 31A and 31B show experimental implantation of
therapeutic devices into the pars plana region 25 of a rabbit eye.
Approximately 4 prototypes of the device as shown in FIG. 7A to
7B-6F were implanted into the rabbit eye. The retention structure
of each devices comprised a substantially clear and transparent
oval flange 122 positioned on the sclera under the conjunctiva. The
clear and transparent flange 122 permits visualization of the
interface of the scleral incision and narrow portion 120N of the
retention structure, such that sealing of the retention structure
to the sclera can be evaluation. The retention structure of each
device also comprise an access port 180 having a substantially
clear penetrable barrier 184 so as to permit dark field
visualization of the location of the implanted device. The narrow
portion 120N of the retention structure is disposed under the
transparent flange, and barrier 160 has the oval shape so to define
the narrow portion of the retention structure.
[0619] These studies showed that the retention structure comprising
the oval flange and oval narrow portion can seal the incision
formed in the sclera and permit dark field visualization of the
implanted device. The device can be implanted temporally in the
patient, for example superior/temporally or inferior/temporally
such that the implant can be disposed temporally and under the
eyelid so as to have a minimal effect on vision and appearance of
the patient.
[0620] FIG. 32A shows the concentration profile of monthly bolus
injections of 2 mg of ranibizumab directly into the vitreous humor
as compared with an injection into the device 100 comprising 4.5 mg
ranibizumab such that 2.5 mg of ranibizumab are stored in the
device and 2 mg of ranibizumab are injected into the eye through
the porous structure 150. Many concentrations of therapeutic agent
can be combined with many reservoir volumes and many RRIs to
provide the 2.0 mg injected through the device and the 2.5 mg
retained in the device, based on the teachings described herein.
The device parameters correspond to a substantially constant 25 uL
reservoir chamber volume of the container of device 100, and an RRI
of about 0.02 as described above. The modeling is based on flushing
of the device with the injector into the vitreous humor of the eye
as described above. The diffusion constants and half-life of
Lucentis in the vitreous humor correspond to those described above
such as the half-life in the vitreous of about nine days and a
vitreous volume of about 4.5 ml.
[0621] The monthly bolus injections of 2 mg correspond to 50 uL
injections of 40 mg/ml ranibizumab as described above and as under
FDA approved clinical study by Genentech. The monthly bolus
injections provide an initial vitreous concentration of about 440
ug/ml that decrease to about 40 ug/ml. The second monthly bolus
injection provides an initial vitreous concentration of about 480
ug/ml based on the combination of the ranibizumab in the vitreous
prior to the second injection and the amount 440 ug provided with
the bolus injection.
[0622] The 4.5 mg injection into the device provides an initial
concentration of about 440 ug/ml based on the 2.0 mg injected
through the device 100 and the 2.5 mg retained in the reservoir
container of device 100. Many concentrations of therapeutic agent
can be combined with many reservoir volumes and many RRIs to
provide the 2.0 mg injected through the device and the 2.5 mg
retained in the device, based on the teachings described herein.
Based on the half life of ranibizumab in the vitreous humor of the
eye and the 440 ug/ml initial concentration, ranibizumab is removed
from the eye with amounts greater than the rate of release of the
therapeutic device 100, such that the initial 440 ug/ml vitreous
concentration provided by the bolus injection through device 100
corresponds to a peak concentration of the ranibizumab
concentration profile. This unexpected result can allow a bolus
injection into the therapeutic device up to an established safe
peak concentration to be combined with the injection into the
therapeutic device without exceeding the established peak safety
concentration when providing release of therapeutic amounts for an
extended time.
[0623] FIG. 32B shows the concentration profile of monthly bolus
injections of 2 mg of ranibizumab directly into the vitreous humor
as compared with a plurality of injections into the device 100
comprising 4.5 mg ranibizumab such that 2.5 mg of ranibizumab are
stored in the device and 2 mg of ranibizumab are injected into the
eye through the porous structure 150. Many concentrations of
therapeutic agent can be combined with many reservoir volumes and
many RRIs to provide the 2.0 mg injected through the device and the
2.5 mg retained in the device, based on the teachings described
herein. The bolus injections directly into the vitreous correspond
substantially to those shown above. The first injection at time 0
into the device 100 corresponds substantially to the injection
shown in FIG. 32A. The second injection of the plurality shows
amount of therapeutic agent 110 comprising ranibizumab to provide a
peak concentration of about 600 ug/ml. The additional concentration
may comprise ranibizumab of the first injection stored in the
therapeutic device 100 when the second injection of 4.5 mg into the
device is performed such that the stored amount is passed through
the porous structure. The third of the plurality of injections
shows a similar peak. These calculations assumed no mixing of the
second injection with the first injection, and 100% fill
efficiency. Based on the teachings described herein, a person of
ordinary skill in the art can adjust the second amount injected
based on one or more of the amount of the therapeutic agent 110
comprising ranibizumab in device 100 from the first injection when
the second injection is performed, the filling efficiency, the
percent mixing, or the efficiency of exchange when used.
[0624] FIG. 32C shows the plurality of ranibizumab injections of
4.5 mg and the monthly bolus injections of 2 mg as in FIG. 32B as
compared with monthly bolus injections of 0.5 mg of commercially
available and approved Lucentis.TM.. Many concentrations of
therapeutic agent can be combined with many reservoir volumes and
many RRIs to provide the 2.0 mg injected through the device and the
2.5 mg retained in the device, based on the teachings described
herein. These data show that the vitreous concentration profile of
ranibizumab from device 100 can be maintained within the
therapeutic window of bolus injections and provide extended release
for at least about 30 days, for example at least about 120
days.
[0625] FIGS. 32D and 32E show injections with amounts into the
device 100 and bolus injections similar to FIGS. 32A to 32C, in
which the injections are performed at 6 months. Many concentrations
of therapeutic agent can be combined with many reservoir volumes
and many RRIs to provide the 2.0 mg injected through the device and
the 2.5 mg retained in the device, based on the teachings described
herein. These data show that the vitreous concentration profile of
ranibizumab from device 100 can be maintained within the
therapeutic window of bolus injections and provide extended release
for at least about 30 days, for example at least about 180 days.
Similar adjustments can be made to the second injection into the
therapeutic device, and injections thereafter, as described above
to maintain the vitreous concentration profile within the peak
profile of the injection.
[0626] FIGS. 33A and 33A1 show a side cross sectional view and a
top view, respectively, of therapeutic device 100 for placement
substantially between the conjunctiva and the sclera. The
therapeutic agent 110 as described herein can be injected when
device 100 is implanted. The therapeutic device 100 comprises
container 130 as described herein having penetrable barrier 184 as
described herein disposed on an upper surface for placement against
the conjunctiva. An elongate structure 172 is coupled to container
130. Elongate structure 172 comprises a channel 174 extending from
a first opening coupled to the chamber of the container to a second
opening 176 on a distal end of the elongate structure. The porous
structure 150 as described herein is located on the elongate
structure 172 and coupled to the container 130 so as to release
therapeutic agent for an extended period, and a retention structure
120 comprising an extension protruding outward from the container
130 to couple to the sclera and the conjunctiva. The container may
comprise barrier 160 as described herein that defines at least a
portion of the reservoir, and the container may comprise a width,
for example a diameter. The barrier 160 may comprise a rigid
material, for example rigid silicone or rigid rubber, or other
material as described herein, such that the volume of the chamber
of container 130 comprises a substantially constant volume as
described herein. Alternatively or in combination, barrier 160 may
comprise a soft material, for example when the chamber size is
decreased such that the volume can be substantially constant with
the decreased chamber size. A soft barrier material can be combined
with a rigid material, for example a support material. The diameter
can be sized within a range, for example within a range from about
1 to about 8 mm, for example within a range from about 2 to 6 mm
and can be about 3 mm, for example.
[0627] The container may be coupled to elongate structure 172
sized, and the elongate structure having a length sized so as to
extend from the conjunctive to the vitreous to release the
therapeutic agent into the vitreous. The length can be sized within
a range, for example within a range from about 2 to about 14 mm,
for example within a range from about 4 to 10 mm and can be about 7
mm, for example. The penetrable barrier may comprise a septum
disposed on a proximal end of the container, in which the septum
comprises a barrier that can be penetrated with a sharp object such
as a needle for injection of the therapeutic agent. The porous
structure may comprise a cross sectional area sized to release the
therapeutic agent for the extended period. The elongate structure
172 can be located near a center of the container 130, or may be
eccentric to the center.
[0628] The elongate structure 172 can be inserted into the sclera
at the pars plana region as described herein.
[0629] The barrier 160 can have a shape profile for placement
between the conjunctiva and sclera. The lower surface can be shaped
to contact the sclera and may comprise a concave shape such as a
concave spherical or toric surface. The upper surface can be shaped
to contact the conjunctivae and may comprise a convex shape such as
a convex spherical or toric surface. The barrier 160 may comprise
an oval, an elliptical, or a circular shape when implanted and
viewed from above, and the elongate structure 172 can be centered
or eccentric to the ellipse. When implanted the long dimension of
the oval can be aligned so as to extend along a circumference of
the pars plana.
[0630] The cross sectional diameter of the elongate structure 172
can be sized to decrease the invasiveness of device 100, and may
comprise a diameter of no more than about 1 mm, for example no more
than about 0.5 mm, for example no more than about 0.25 mm such that
the penetrate sclera seals substantially when elongate structure
172 is removed and the eye can seal itself upon removal of elongate
structure 172. The elongate structure 172 may comprise a needle,
and channel 174 may comprise a lumen of the needle, for example a
30 Gauge needle.
[0631] The porous structure 150 may comprise a first side a
described herein coupled to the reservoir and a second side to
couple to the vitreous. The first side may comprise a first area
150 as described herein and the second side may comprise a second
area. The porous structure may comprise a thickness as described
herein. The porous structure many comprise a diameter. The porous
structure may comprise a release rate index, and the chamber of
container 130 that defines the volume of reservoir 140 can be sized
such that the porous structure and the volume are tuned to receive
and amount of therapeutic agent injected with a volume of
formulation of therapeutic agent and tuned to release therapeutic
amounts for an extended time. Many release rate mechanisms as
described herein can be used to tune the release rate and volume to
the quantity of therapeutic agent injected as described herein.
[0632] The volume of the reservoir 140 defined by the chamber of
the container may comprise from about 5 uL to about 2000 uL of
therapeutic agent, or for example from about 10 uL to about 200 uL
of therapeutic agent.
[0633] The porous structure may comprise a needle stop that limits
penetration of the needle. The porous structure may comprise a
plurality of channels configured for the extended release of the
therapeutic agent. The porous structure may comprise a rigid
sintered material having characteristics suitable for the sustained
release of the material.
[0634] FIG. 33A2 shows the therapeutic device 100 implanted with
the reservoir between the conjunctiva and the sclera, such that
elongate structure 172 extends through the sclera to couple the
reservoir chamber to the vitreous humor. When implanted, the porous
structure 150 can be located in the vitreous humor, or located
between the conjunctiva and sclera, or may extend through the
sclera, or combinations thereof.
[0635] FIG. 33B shows the porous structure 150 of therapeutic
device 100 located in channel 174 near the opening to the chamber
of the container 130. The porous structure can extend substantially
along the length of elongate structure 172.
[0636] FIG. 33C shows the porous structure 150 located within the
chamber of container 150 and coupled to the first opening of the
elongate structure 172 so as to provide the release rate profile.
The porous structure can cover the opening of elongate structure
172 such that therapeutic amounts are released for the extended
time as described herein.
[0637] FIG. 33D shows a plurality of injection ports spaced apart
so as to inject and exchange the liquid of chamber of the container
130 and inject the therapeutic agent into the reservoir chamber of
the container 130. The penetrable barrier 184 may comprise a first
penetrable barrier located in a first access port formed in the
barrier 160 and a second penetrable barrier located in a second
access port formed in the barrier 160, and the first barrier can be
separated from the second barrier by at least about 1 mm.
[0638] The injector 701 as described above can be configured to
coupled to the reservoir placed between the conjunctiva and the
sclera as describe herein. The injector 701 can be coupled to a
double lumen needle 189L such that a second lumen 189B injects
therapeutic agent 110 from a chamber 702C into device 100, and the
first lumen can be spaced apart from the second lumen with the
distance extending therebetween sized to position the first lumen
in the first septum as described above and the second lumen in the
second septum as described above. The second container 703C can be
coupled to a first lumen 189A that extends to the chamber of the
reservoir container and receives liquid from device 100, such that
liquid of device 100 is exchanged when the chamber of the reservoir
container is positioned between the conjunctiva and the sclera. The
switching valve 703V to exchange an intended amount of liquid and
an intended amount of the formulation the therapeutic agent 110,
and inject an intended amount of therapeutic agent injected into
device 100, for example such that a bolus amount of therapeutic
agent can be injected from device 100 as described above. A portion
of the formulation of therapeutic agent injected into device 100
can be retained in device 100 for release for an extended time.
[0639] FIG. 34 shows the elongate structure 172 coupled to the
container 130 away from the center of container 130 and near and
located near an end of the container.
[0640] Materials for Porous Structures and Housing
[0641] The material of the housing and porous structure may
comprise a material having a decreased interaction with the
therapeutic agent such as ranibizumab.
[0642] FIG. 35 shows stability data for a formulation of Lucentis
that can be used to identify materials for porous frit structures.
These data show the stability of Lucentis over time for containers
having materials such as stainless steel, Ti, PMMA and silicone.
These data were measured with ion exchange chromatography, and can
be measured in accordance with published references describing Mab
patterns on SCX-10 column. The data were measured in accordance
with references on the Dionex website, such as: [0643] Development
data by the Manufacturer Dionex Corp. [0644] Title: MAbPac SCX-10
Column for Monoclonal Antibody Variant Analysis [0645]
http://www.dionex.com/en-us/webdocs/87008-DS-MAbPac-SCX-10-Column--
20Aug2010-LPN2567-03.pdf
[0646] Table VV shows recovery and stability of Lucentis with
materials that can be used for porous structure 150 as described
herein. Additional testing of additional materials can be
performed, for example with one or more ceramic materials. Table VV
shows Ion Exchange Chromatography of Lucentis with Device
Components in Accelerated Stability for Lucentis 1 mg/mL pH 7.3
(PBS) for 35 days. Recovery was corrected for the evaporated water
lost during the stability (8.0%). Data was very repeatable. 3
injections, area integration within+8% RSD.
TABLE-US-00028 TABLE VV RECOVERY AND STABILITY OF LUCENTIS WITH
MATERIALS FOR POROUS STRUCTURES Component Study 37.degree. C. 35
Days Sample % Recovery Average % Purity Control 37.degree. C. 98.1
87.3 Stainless 37.degree. C. 89.5 68.8 Titanium 37.degree. C. 96.2
80.8 PMMA 37.degree. C. 97.8 88.2 Silicone 37.degree. C. 98.0
87.3
[0647] The above data indicate that Titanium (Ti), acrylate polymer
such as PMMA, or siloxane such as silicone may provide increased
stability as compared to stainless steel in at least some
instances. Similar testing can be performed on additional materials
as described herein, for example with one or more ceramic
materials.
[0648] Based on the teachings described herein, a person of
ordinary skill in the art can conduct experiments to determine
empirically the release rate index of the porous structure 150 for
the material identified, such as titanium. For example, gas flow
data measured as described herein have shown that for a given
material such as stainless steel, media grade and porosity, the gas
flow data such as flow rate or decay time can be correlated with
the release rate index, such that a porous structure 150 can be
identified based on material, gas flow data, media grade and
porosity. The correlation between gas flow data and release rate
index for a sintered porous structure having a known material,
media grade and porosity can be used to determine the release rate
index of the porous structure.
[0649] The porous structure 150 can be combined with amounts of
therapeutic agent, for example ranibizumab, so as to provide
extended release with a plurality of injections for an extended
time post each injection.
[0650] Amounts of Ranibizumab
[0651] Based on the teachings described herein, amounts of
ranibizumab can be injected into device 100 in many ways so as to
provide an intended amount of therapeutic agent at or above a
target amount for an extended time, such as 3 months or 6 months,
for example. The device 100 may comprise the subjconctival device,
for example, or may comprise a device having the reservoir located
substantially in the vitreous. Based on the teachings described
herein, the target amount of release at an extended time post
injection, for example 3 months or 6 months, can be used to
determine the amount of therapeutic agent. The reservoir can be
sized based on the concentration of formulation and amount of
therapeutic agent, and the RRI determined based on the amount
released at the extended time post injection and the concentration
of formulation.
[0652] Table WW provides examples of amounts of therapeutic agents
that can be injected into a reservoir of the therapeutic device,
and amounts of the therapeutic agent ranibizumab that can be
released when the reservoir and porous structure are tuned to
receive the amount of therapeutic agent. Table WW shows amounts of
ranibizumab therapeutic agent from about 0.1 mg to about 30 mg.
These amounts can be combined with over injection above the amount
of reservoir capacity to release a bolus and with exchange as
described herein, for example when the amount of Table WW
corresponds to the reservoir capacity of the therapeutic device
100.
TABLE-US-00029 TABLE WW Amounts of ranibizumab therapeutic agent
released at 90 and 180 days with RRI tuned to reservoir volume and
concentration of therapeutic agent. rate at 90 days rate at 180
days rri mg protein ug/day ug/day 0.01 0.10 0.4 0.2 0.02 0.10 0.4
0.1 0.04 0.10 0.2 0.0 0.06 0.10 0.0 0.0 0.08 0.10 0.0 0.0 0.01 0.15
0.5 0.3 0.02 0.15 0.6 0.2 0.04 0.15 0.4 0.1 0.06 0.15 0.2 0.0 0.08
0.15 0.1 0.0 0.01 0.20 0.6 0.4 0.02 0.20 0.8 0.4 0.04 0.20 0.7 0.2
0.06 0.20 0.5 0.0 0.08 0.20 0.3 0.0 0.01 0.25 0.6 0.5 0.02 0.25 0.9
0.5 0.04 0.25 1.0 0.3 0.06 0.25 0.8 0.1 0.08 0.25 0.6 0.0 0.01 0.30
0.7 0.5 0.02 0.30 1.0 0.6 0.04 0.30 1.2 0.4 0.06 0.30 1.1 0.2 0.08
0.30 0.9 0.1 0.01 0.40 0.7 0.6 0.02 0.40 1.2 0.8 0.04 0.40 1.6 0.7
0.06 0.40 1.6 0.5 0.08 0.40 1.5 0.3 0.01 0.50 0.7 0.6 0.02 0.50 1.3
0.9 0.04 0.50 1.9 1.0 0.06 0.50 2.0 0.8 0.08 0.50 2.0 0.6 0.01 0.40
1.6 0.7 0.01 0.60 2.1 1.2 0.01 0.80 2.3 1.6 0.01 1.00 2.5 1.9 0.01
1.20 2.7 2.1 0.01 1.60 2.8 2.3 0.01 2.00 3.0 2.5 0.02 0.40 1.5 0.3
0.02 0.60 2.5 0.9 0.02 0.80 3.2 1.5 0.02 1.00 3.7 2.0 0.02 1.20 4.1
2.5 0.02 1.60 4.7 3.3 0.02 2.00 5.1 3.7 0.04 0.40 0.6 0.0 0.04 0.60
1.7 0.2 0.04 0.80 2.9 0.6 0.04 1.00 4.0 1.1 0.04 1.20 4.9 1.7 0.04
1.60 6.4 2.9 0.04 2.00 7.4 4.0 0.06 0.40 0.2 0.0 0.06 0.60 0.9 0.0
0.06 0.80 2.0 0.2 0.06 1.00 3.2 0.5 0.06 1.20 4.4 0.9 0.06 1.60 6.5
2.0 0.06 2.00 8.2 3.2 0.08 0.40 0.1 0.0 0.08 0.60 0.4 0.0 0.08 0.80
1.2 0.1 0.08 1.00 2.3 0.2 0.08 1.20 3.5 0.4 0.08 1.60 5.8 1.2 0.08
2.00 8.0 2.3 0.01 1.00 4.0 1.8 0.02 1.00 3.6 0.8 0.04 1.00 1.5 0.1
0.06 1.00 0.5 0.0 0.08 1.00 0.1 0.0 0.01 1.50 5.1 3.1 0.02 1.50 6.1
2.2 0.04 1.50 4.3 0.5 0.06 1.50 2.3 0.1 0.08 1.50 1.1 0.0 0.01 2.00
5.9 4.0 0.02 2.00 7.9 3.6 0.04 2.00 7.3 1.5 0.06 2.00 5.0 0.5 0.08
2.00 3.1 0.1 0.01 2.50 6.3 4.6 0.02 2.50 9.3 5.0 0.04 2.50 10.0 2.9
0.06 2.50 8.0 1.2 0.08 2.50 5.7 0.5 0.01 3.00 6.7 5.1 0.02 3.00
10.3 6.1 0.04 3.00 12.3 4.3 0.06 3.00 10.9 2.3 0.08 3.00 8.7 1.1
0.01 4.00 7.1 5.9 0.02 4.00 11.7 7.9 0.04 4.00 15.9 7.3 0.06 4.00
16.1 5.0 0.08 4.00 14.6 3.1 0.01 5.00 7.4 6.3 0.02 5.00 12.7 9.3
0.04 5.00 18.6 10.0 0.06 5.00 20.4 8.0 0.08 5.00 19.9 5.7 0.01 2.00
7.9 3.6 0.01 3.00 10.3 6.1 0.01 4.00 11.7 7.9 0.01 5.00 12.7 9.3
0.01 6.00 13.3 10.3 0.01 8.00 14.2 11.7 0.01 10.00 14.8 12.7 0.02
2.00 7.3 1.5 0.02 3.00 12.3 4.3 0.02 4.00 15.9 7.3 0.02 5.00 18.6
10.0 0.02 6.00 20.6 12.3 0.02 8.00 23.4 15.9 0.02 10.00 25.3 18.6
0.04 2.00 3.1 0.1 0.04 3.00 8.7 1.1 0.04 4.00 14.6 3.1 0.04 5.00
19.9 5.7 0.04 6.00 24.5 8.7 0.04 8.00 31.8 14.6 0.04 10.00 37.1
19.9 0.06 2.00 1.0 0.0 0.06 3.00 4.6 0.2 0.06 4.00 10.1 1.0 0.06
5.00 16.0 2.5 0.06 6.00 21.9 4.6 0.06 8.00 32.3 10.1 0.06 10.00
40.8 16.0 0.08 2.00 0.3 0.0 0.08 3.00 2.2 0.0 0.08 4.00 6.2 0.3
0.08 5.00 11.5 1.0 0.08 6.00 17.4 2.2 0.08 8.00 29.2 6.2 0.08 10.00
39.8 11.5 0.01 4.00 15.9 7.3 0.01 6.00 20.6 12.3 0.01 8.00 23.4
15.9 0.01 10.00 25.3 18.6 0.01 12.00 26.7 20.6 0.01 16.00 28.5 23.4
0.01 20.00 29.6 25.3 0.02 4.00 14.6 3.1 0.02 6.00 24.5 8.7 0.02
8.00 31.8 14.6 0.02 10.00 37.1 19.9 0.02 12.00 41.2 24.5 0.02 16.00
46.9 31.8 0.02 20.00 50.6 37.1 0.04 4.00 6.2 0.3 0.04 6.00 17.4 2.2
0.04 8.00 29.2 6.2 0.04 10.00 39.8 11.5 0.04 12.00 49.0 17.4 0.04
16.00 63.5 29.2 0.04 20.00 74.2 39.8 0.06 4.00 2.0 0.0 0.06 6.00
9.2 0.4 0.06 8.00 20.1 2.0 0.06 10.00 32.1 5.0 0.06 12.00 43.8 9.2
0.06 16.00 64.6 20.1 0.06 20.00 81.6 32.1 0.08 4.00 0.5 0.0 0.08
6.00 4.4 0.1 0.08 8.00 12.3 0.5 0.08 10.00 23.0 1.9 0.08 12.00 34.8
4.4 0.08 16.00 58.3 12.3 0.08 20.00 79.7 23.0 0.01 6.00 23.8 10.9
0.01 9.00 30.9 18.4 0.01 12.00 35.1 23.8 0.01 15.00 38.0 27.8 0.01
18.00 40.0 30.9 0.01 24.00 42.7 35.1 0.01 30.00 44.4 38.0 0.02 6.00
21.9 4.6 0.02 9.00 36.8 13.0 0.02 12.00 47.6 21.9 0.02 15.00 55.7
29.9 0.02 18.00 61.7 36.8 0.02 24.00 70.3 47.6 0.02 30.00 76.0 55.7
0.04 6.00 9.2 0.4 0.04 9.00 26.1 3.3 0.04 12.00 43.8 9.2 0.04 15.00
59.8 17.2 0.04 18.00 73.5 26.1 0.04 24.00 95.3 43.8 0.04 30.00
111.3 59.8 0.06 6.00 2.9 0.0 0.06 9.00 13.9 0.6 0.06 12.00 30.2 2.9
0.06 15.00 48.1 7.4 0.06 18.00 65.7 13.9 0.06 24.00 96.9 30.2 0.06
30.00 122.3 48.1 0.08 6.00 0.8 0.0 0.08 9.00 6.6 0.1 0.08 12.00
18.5 0.8 0.08 15.00 34.4 2.9 0.08 18.00 52.1 6.6 0.08 24.00 87.6
18.5 0.08 30.00 119.5 34.4
[0653] The above Table WW shows examples of amounts of therapeutic
agent that can be placed in the therapeutic device 100 for release,
and the amounts can correspond to ranges of an amount. For example,
the amount can be within a range of two or more values of Table WW,
for example within a range from about 6 to about 9 mg of
ranibizumab. The amount of the therapeutic agent such as
ranibizumab can be more or less than the amounts shown in Table
WW.
[0654] Concentrations, Reservoir Container Volumes and Amounts of
Ranibizumab
[0655] Based on the teachings described herein, amounts of
ranibizumab can be injected into device 100 in many ways so as to
provide an intended amount of therapeutic agent at or above an
target amount for an extended time, such as 3 months or 6 months,
for example. The porous structure of device 150 may comprise a
sintered porous material having improved stability, for example as
described with reference to Table VV.
[0656] Ranibizumab can be provided for injection into the
therapeutic device based on a lyophilized powder that can be mixed
and diluted to a desired concentration. Table X shows
concentrations of ranibizumab formulations. Similar formulations
can be provided with many therapeutic agents as described herein.
Intermediate concentrations to the values shown in Table X may be
used, and also values above and below the values shown in Table X.
The European approval of ranibizumab indicates that a lyophilized
form was initially used, and this lyophilized ranibizumab can be
diluted to many appropriate concentrations as described herein. The
European approval indicates that the frozen drug substance can be
diluted to make the final drug product, such that concentrations of
the drug higher than that in the current approved European product
can be achieved in accordance with the teachings as described
herein. (See European Medicine Agency, Scientific Discussion;
retrievable from the Internet; [0657]
<http://www.ema.europa.eu/docs/en GB/document library/EPAR
Scientific Discussion/hu man/000715/WC500043550.pdf>, EMEA 2007,
54 pages total.)
[0658] The concentration of diluted ranibizumab can be within a
range from about 10 mg/mL to about 600 mg/mL, for example. And the
concentration can be within a range corresponding to a first value
of Table X and a second value of Table X for example within a range
from about 230 to about 260 mg/mL as shown in Table X. A person of
ordinary skill in the art can conduct experiments to determine the
value based on the teachings described herein.
TABLE-US-00030 TABLE X Concentrations of ranibizumab suitable for
injection. Concentration mg/ml 10 20 30 40 50 60 70 80 90 100 110
120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280
290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450
460 470 480 490 500 510 520 530 540 550 560 570 580 590 600
[0659] Based on the teachings described herein, many amounts of
therapeutic agent can be released above an intended target amount
for an intended extended time, and many amounts of Lucentis can be
used to provide the intended amount.
[0660] Table YY shows examples of formulations and RRI such that
that amounts of Ranibizumab can be released at 90 and 180 days so
as to provide a rate of release continuously above a target amount
from the time of injection to the time shown in Table YY. These
amounts can be combined with over injection above the amount of
reservoir capacity to release a bolus and with exchange as
described herein, for example.
TABLE-US-00031 TABLE YY Amounts of Ranibizumab Release at 90 and
180 days for device amounts from about 0.1 mg to about 30 mg
Ranibizumab. pds vol conc rate at 90 days rate at 180 days Ml rri
mg/ml mg protein ug/day ug/day 0.01 0.01 10 0.10 0.4 0.2 0.01 0.02
10 0.10 0.4 0.1 0.01 0.04 10 0.10 0.2 0.0 0.01 0.06 10 0.10 0.0 0.0
0.01 0.08 10 0.10 0.0 0.0 0.015 0.01 10 0.15 0.5 0.3 0.015 0.02 10
0.15 0.6 0.2 0.015 0.04 10 0.15 0.4 0.1 0.015 0.06 10 0.15 0.2 0.0
0.015 0.08 10 0.15 0.1 0.0 0.02 0.01 10 0.20 0.6 0.4 0.02 0.02 10
0.20 0.8 0.4 0.02 0.04 10 0.20 0.7 0.2 0.02 0.06 10 0.20 0.5 0.0
0.02 0.08 10 0.20 0.3 0.0 0.025 0.01 10 0.25 0.6 0.5 0.025 0.02 10
0.25 0.9 0.5 0.025 0.04 10 0.25 1.0 0.3 0.025 0.06 10 0.25 0.8 0.1
0.025 0.08 10 0.25 0.6 0.0 0.03 0.01 10 0.30 0.7 0.5 0.03 0.02 10
0.30 1.0 0.6 0.03 0.04 10 0.30 1.2 0.4 0.03 0.06 10 0.30 1.1 0.2
0.03 0.08 10 0.30 0.9 0.1 0.04 0.01 10 0.40 0.7 0.6 0.04 0.02 10
0.40 1.2 0.8 0.04 0.04 10 0.40 1.6 0.7 0.04 0.06 10 0.40 1.6 0.5
0.04 0.08 10 0.40 1.5 0.3 0.05 0.01 10 0.50 0.7 0.6 0.05 0.02 10
0.50 1.3 0.9 0.05 0.04 10 0.50 1.9 1.0 0.05 0.06 10 0.50 2.0 0.8
0.05 0.08 10 0.50 2.0 0.6 0.01 0.01 40 0.40 1.6 0.7 0.015 0.01 40
0.60 2.1 1.2 0.02 0.01 40 0.80 2.3 1.6 0.025 0.01 40 1.00 2.5 1.9
0.03 0.01 40 1.20 2.7 2.1 0.04 0.01 40 1.60 2.8 2.3 0.05 0.01 40
2.00 3.0 2.5 0.01 0.02 40 0.40 1.5 0.3 0.015 0.02 40 0.60 2.5 0.9
0.02 0.02 40 0.80 3.2 1.5 0.025 0.02 40 1.00 3.7 2.0 0.03 0.02 40
1.20 4.1 2.5 0.04 0.02 40 1.60 4.7 3.3 0.05 0.02 40 2.00 5.1 3.7
0.01 0.04 40 0.40 0.6 0.0 0.015 0.04 40 0.60 1.7 0.2 0.02 0.04 40
0.80 2.9 0.6 0.025 0.04 40 1.00 4.0 1.1 0.03 0.04 40 1.20 4.9 1.7
0.04 0.04 40 1.60 6.4 2.9 0.05 0.04 40 2.00 7.4 4.0 0.01 0.06 40
0.40 0.2 0.0 0.015 0.06 40 0.60 0.9 0.0 0.02 0.06 40 0.80 2.0 0.2
0.025 0.06 40 1.00 3.2 0.5 0.03 0.06 40 1.20 4.4 0.9 0.04 0.06 40
1.60 6.5 2.0 0.05 0.06 40 2.00 8.2 3.2 0.01 0.08 40 0.40 0.1 0.0
0.015 0.08 40 0.60 0.4 0.0 0.02 0.08 40 0.80 1.2 0.1 0.025 0.08 40
1.00 2.3 0.2 0.03 0.08 40 1.20 3.5 0.4 0.04 0.08 40 1.60 5.8 1.2
0.05 0.08 40 2.00 8.0 2.3 0.01 0.01 100 1.00 4.0 1.8 0.01 0.02 100
1.00 3.6 0.8 0.01 0.04 100 1.00 1.5 0.1 0.01 0.06 100 1.00 0.5 0.0
0.01 0.08 100 1.00 0.1 0.0 0.015 0.01 100 1.50 5.1 3.1 0.015 0.02
100 1.50 6.1 2.2 0.015 0.04 100 1.50 4.3 0.5 0.015 0.06 100 1.50
2.3 0.1 0.015 0.08 100 1.50 1.1 0.0 0.02 0.01 100 2.00 5.9 4.0 0.02
0.02 100 2.00 7.9 3.6 0.02 0.04 100 2.00 7.3 1.5 0.02 0.06 100 2.00
5.0 0.5 0.02 0.08 100 2.00 3.1 0.1 0.025 0.01 100 2.50 6.3 4.6
0.025 0.02 100 2.50 9.3 5.0 0.025 0.04 100 2.50 10.0 2.9 0.025 0.06
100 2.50 8.0 1.2 0.025 0.08 100 2.50 5.7 0.5 0.03 0.01 100 3.00 6.7
5.1 0.03 0.02 100 3.00 10.3 6.1 0.03 0.04 100 3.00 12.3 4.3 0.03
0.06 100 3.00 10.9 2.3 0.03 0.08 100 3.00 8.7 1.1 0.04 0.01 100
4.00 7.1 5.9 0.04 0.02 100 4.00 11.7 7.9 0.04 0.04 100 4.00 15.9
7.3 0.04 0.06 100 4.00 16.1 5.0 0.04 0.08 100 4.00 14.6 3.1 0.05
0.01 100 5.00 7.4 6.3 0.05 0.02 100 5.00 12.7 9.3 0.05 0.04 100
5.00 18.6 10.0 0.05 0.06 100 5.00 20.4 8.0 0.05 0.08 100 5.00 19.9
5.7 0.01 0.01 200 2.00 7.9 3.6 0.015 0.01 200 3.00 10.3 6.1 0.02
0.01 200 4.00 11.7 7.9 0.025 0.01 200 5.00 12.7 9.3 0.03 0.01 200
6.00 13.3 10.3 0.04 0.01 200 8.00 14.2 11.7 0.05 0.01 200 10.00
14.8 12.7 0.01 0.02 200 2.00 7.3 1.5 0.015 0.02 200 3.00 12.3 4.3
0.02 0.02 200 4.00 15.9 7.3 0.025 0.02 200 5.00 18.6 10.0 0.03 0.02
200 6.00 20.6 12.3 0.04 0.02 200 8.00 23.4 15.9 0.05 0.02 200 10.00
25.3 18.6 0.01 0.04 200 2.00 3.1 0.1 0.015 0.04 200 3.00 8.7 1.1
0.02 0.04 200 4.00 14.6 3.1 0.025 0.04 200 5.00 19.9 5.7 0.03 0.04
200 6.00 24.5 8.7 0.04 0.04 200 8.00 31.8 14.6 0.05 0.04 200 10.00
37.1 19.9 0.01 0.06 200 2.00 1.0 0.0 0.015 0.06 200 3.00 4.6 0.2
0.02 0.06 200 4.00 10.1 1.0 0.025 0.06 200 5.00 16.0 2.5 0.03 0.06
200 6.00 21.9 4.6 0.04 0.06 200 8.00 32.3 10.1 0.05 0.06 200 10.00
40.8 16.0 0.01 0.08 200 2.00 0.3 0.0 0.015 0.08 200 3.00 2.2 0.0
0.02 0.08 200 4.00 6.2 0.3 0.025 0.08 200 5.00 11.5 1.0 0.03 0.08
200 6.00 17.4 2.2 0.04 0.08 200 8.00 29.2 6.2 0.05 0.08 200 10.00
39.8 11.5 0.01 0.01 400 4.00 15.9 7.3 0.015 0.01 400 6.00 20.6 12.3
0.02 0.01 400 8.00 23.4 15.9 0.025 0.01 400 10.00 25.3 18.6 0.03
0.01 400 12.00 26.7 20.6 0.04 0.01 400 16.00 28.5 23.4 0.05 0.01
400 20.00 29.6 25.3 0.01 0.02 400 4.00 14.6 3.1 0.015 0.02 400 6.00
24.5 8.7 0.02 0.02 400 8.00 31.8 14.6 0.025 0.02 400 10.00 37.1
19.9 0.03 0.02 400 12.00 41.2 24.5 0.04 0.02 400 16.00 46.9 31.8
0.05 0.02 400 20.00 50.6 37.1 0.01 0.04 400 4.00 6.2 0.3 0.015 0.04
400 6.00 17.4 2.2 0.02 0.04 400 8.00 29.2 6.2 0.025 0.04 400 10.00
39.8 11.5 0.03 0.04 400 12.00 49.0 17.4 0.04 0.04 400 16.00 63.5
29.2 0.05 0.04 400 20.00 74.2 39.8 0.01 0.06 400 4.00 2.0 0.0 0.015
0.06 400 6.00 9.2 0.4 0.02 0.06 400 8.00 20.1 2.0 0.025 0.06 400
10.00 32.1 5.0 0.03 0.06 400 12.00 43.8 9.2 0.04 0.06 400 16.00
64.6 20.1 0.05 0.06 400 20.00 81.6 32.1 0.01 0.08 400 4.00 0.5 0.0
0.015 0.08 400 6.00 4.4 0.1 0.02 0.08 400 8.00 12.3 0.5 0.025 0.08
400 10.00 23.0 1.9 0.03 0.08 400 12.00 34.8 4.4 0.04 0.08 400 16.00
58.3 12.3 0.05 0.08 400 20.00 79.7 23.0 0.01 0.01 600 6.00 23.8
10.9 0.015 0.01 600 9.00 30.9 18.4 0.02 0.01 600 12.00 35.1 23.8
0.025 0.01 600 15.00 38.0 27.8 0.03 0.01 600 18.00 40.0 30.9 0.04
0.01 600 24.00 42.7 35.1 0.05 0.01 600 30.00 44.4 38.0 0.01 0.02
600 6.00 21.9 4.6 0.015 0.02 600 9.00 36.8 13.0 0.02 0.02 600 12.00
47.6 21.9 0.025 0.02 600 15.00 55.7 29.9 0.03 0.02 600 18.00 61.7
36.8 0.04 0.02 600 24.00 70.3 47.6 0.05 0.02 600 30.00 76.0 55.7
0.01 0.04 600 6.00 9.2 0.4 0.015 0.04 600 9.00 26.1 3.3 0.02 0.04
600 12.00 43.8 9.2 0.025 0.04 600 15.00 59.8 17.2 0.03 0.04 600
18.00 73.5 26.1 0.04 0.04 600 24.00 95.3 43.8 0.05 0.04 600 30.00
111.3 59.8 0.01 0.06 600 6.00 2.9 0.0 0.015 0.06 600 9.00 13.9 0.6
0.02 0.06 600 12.00 30.2 2.9 0.025 0.06 600 15.00 48.1 7.4 0.03
0.06 600 18.00 65.7 13.9 0.04 0.06 600 24.00 96.9 30.2 0.05 0.06
600 30.00 122.3 48.1 0.01 0.08 600 6.00 0.8 0.0 0.015 0.08 600 9.00
6.6 0.1 0.02 0.08 600 12.00 18.5 0.8 0.025 0.08 600 15.00 34.4 2.9
0.03 0.08 600 18.00 52.1 6.6 0.04 0.08 600 24.00 87.6 18.5 0.05
0.08 600 30.00 119.5 34.4
[0661] FIG. 36A shows amounts of ranibizumab released at about 90
days for a 100 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0662] FIG. 36B shows amounts of ranibizumab released at about 180
days for a 100 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0663] FIG. 36C shows amounts of ranibizumab released at about 90
days for a 10 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0664] FIG. 36D shows amounts of ranibizumab released at about 180
days for a 10 mg/mL formulation of Ranibizumab and the
corresponding reservoir chamber volume from about 10 uL to about 50
uL and the corresponding RRI from about 0.01 to about 0.08;
[0665] The above data show that smaller RRIs can provide tuned
optimal release rates as the device volume is decreased, for
example tuned to a target amount released per day and as can be
seen with reference to FIGS. 36A and 36B. The rate of release can
be directly proportional to the concentration loaded into the
device, for example as seen with reference to FIGS. 36B and
36D.
[0666] FIG. 37 shows vitreous humor concentration profiles
corresponding to ranibizumab formulations of 40 mg/mL and 100 mg/mL
injected into the therapeutic device. These concentration profiles
were determined with modeling and calculations as described herein.
These values are shown for an RRI=0.02, a device volume=25 uL, and
100% refill exchange efficiency. The other parameters such as the
diffusion coefficient are described herein. The concentration for
the 100 mg/mL injections range from about 40 ug/mL to about 25
ug/mL, and the concentrations for 40 mg/mL injections range from
about 15 ug/mL to about 10 ug/mL. For intermediate concentrations
of the injected formulation, the values can be in between those
shown for 40 mg/mL and 100 mg/mL. The sequential injections can
provide treatment for an extended time, for example one year.
[0667] EXAMPLE A: Measured release rate profiles for Ranibizumab
(Lucentis.TM.) formulations of 40 and 100 mg/mL from therapeutic
devices and porous titanium frit structures corresponding to a
device half life of 100 days
[0668] The Device effective Half-life with Ranibizumab=100 days.
The volume of the device reservoir in this example was 25 uL, and
the RRI was about 0.02 for a diffusion coefficient of Ranibizumab
of 1.times.10.sup.-6 cm.sup.2/s.
[0669] Drug Release Studies were performed using ranibizumab
formulations of 40 or 100 mg/mL. The Ranibizumab was formulated in
histidine, with trehalose dehydrate, and polysorbate 20, in
accordance with U.S. patent application Ser. No. 12/554194, Pub.
No. 2010/0015157, entitled "Antibody Formulations", the full
disclosure of which is incorporated herein by reference.
[0670] Devices were fabricated using the following method. A vessel
was made from two subassemblies and a porous frit structure as
described herein. The porous frit structure had a thickness of
about 0.04 in, and an OD of about 0.03 in. The intended RRI was
about 0.02 based on gas flow measurements and manufacturing as
described herein. The implantable devices were manufactured in
accordance with the teachings as described herein.
[0671] Devices were filled with formulation using a 33 G needle
(TSK) and a standard tuberculin 1-cc syringe (BD). Excess liquid
that had exited the porous sintered frit structure during filling
was removed by use of a lab tissue and submerging in phosphate
buffered saline (PBS, Sigma) and 0.02% sodium azide as a
preservative. Each device was suspended in the center of a 1.5 mL
microcentrifuge tube by use of a fixture. The tube was filled with
0.5 mL receiver fluid; i.e., PBS that had been degassed to minimize
bubble formation. At selected times, the device was removed from
the receiver fluid and placed in a new tube containing fresh
receiver fluid. For the first time points that were collected
within short time intervals, the concentration of Ranibizumab in
the receiver fluid was determined using a Micro BCATM Protein Assay
Kit (Pierce) and a Microplate reader (Molecular Devices). For the
later time points, the sample concentrations were higher and
concentration was determined by UV (Perkin Elmer Lambda 35). Drug
release rates were calculated from measured concentration, the
volume of the receiver fluid and the duration of the collection
interval. Drug release rate profiles were plotted at the average
elapsed time for each collection interval. RRI was determined via a
least squares fit to the model.
[0672] Each formulation was filled into ten devices. Some devices
were stopped at 3 and 4 months (n=3 each), leaving four that
underwent drug release testing for 180 days.
[0673] Table Z1 shows the measured RRI and the corresponding max,
min and standard deviations for the devices receiving 40 and 100
mg/mL formulations. The measured mean RRI for both 40 and 100 mg/mL
formulations was 0.02, with a standard deviation of 0.002 and 0.001
for the 40 and 100 mg/mL formulations, respectively. The mean RRI
of 0.02 and release rates show that the therapeutic device 100 can
provide the therapeutic agent device half life of approximately 100
days.
TABLE-US-00032 TABLE Z1 RRI (mm) Formulation (mg/mL) 40 100 Mean
0.024 0.021 SD 0.002 0.001 Min 0.021 0.018 Max 0.027 0.023
[0674] FIG. 37A shows release of Ranibizumab formulations to 180
days from a therapeutic device comprising an RRI of 0.02 and a
volume of 25 uL corresponding to an effective half life of the
therapeutic agent in the device of 100 days. The injection of 40
mg/mL to the 25 uL device corresponds to 1 mg of ranibizumab
injected into the reservoir chamber of the device and 100 mg/mL
corresponds to 2.5 mg of ranibizumab injected into the reservoir
chamber of the device.
[0675] EXAMPLE B: Measured release rate profiles for Ranibizumab
(Lucentis.TM.) formulations of 100 mg/mL from therapeutic devices
and porous titanium frit structures corresponding to a device half
life of 250 days
[0676] Devices were fabricated as described above with reference to
Example A. The titanium porous frit structures had a thickness of
0.031 in and an OD of 0.031. The intended RRI was about 0.008 based
on gas flow measurements and manufacturing as described herein. The
therapeutic device reservoir volume was about 25 uL. The effective
half-life for these devices was about 250 days.
[0677] The formulation was filled into five devices and all
underwent drug release testing for 180 days.
[0678] Table Z2 shows the measured RRI and the corresponding max,
min and standard deviations for the devices receiving the 100 mg/mL
formulations. The mean RRI of 0.008 and release rates show that the
therapeutic device 100 can provide the therapeutic agent device
half life of approximately 250 days.
TABLE-US-00033 TABLE Z2 Measured RRI of Therapeutic Devices RRI
(mm) Formulation (mg/mL) 100 Mean 0.008 SD 0.001 Min 0.007 Max
0.009
[0679] Table Z3A shows release of Ranibizumab at 90 and 180 days
for the therapeutic devices having the 100 day half life. These
data correspond to the tuned reservoir volume and release rate of
the porous structure as described herein, for example with
reference to the 90 and 180 day release rates of FIGS. 36A and 36B,
respectively.
TABLE-US-00034 TABLE Z3A Release rates of Ranibizumab 100 mg/mL
Rate 40 mg/mL Rate Day 90 180 90 180 Average 9.51 5.13 5.52 2.42 SD
0.54 0.10 0.05 0.09 Min 8.83 5.02 5.46 2.32 Max 10.28 5.26 5.56
2.52 n = 7 4 7 4
[0680] FIG. 37B shows release of Ranibizumab to 180 days from a
therapeutic device comprising an RRI of 0.008 and a volume of 25 uL
corresponding to an effective half life of the therapeutic agent in
the device of 250 days.
TABLE-US-00035 TABLE Z3B Release of Ranibizumab at 90 and 175 days
for the therapeutic devices having the 250 day half life. 100 mg/mL
Rate Day 90 180 Average 5.59 4.51 SD 0.26 0.16 Min 5.29 4.37 Max
5.89 4.75 n = 5 5
[0681] The of data FIG. 37B and Table Z3B show that therapeutic
amounts of at least about 4 to 5 ug/day can be released for at
least about 180 days, for example 5.6 ug/day and 4.5 ug/day at 90
and 180 days, respectively. While the devices corresponding to FIG.
37A were tuned to provide maximal delivery rates at 4-6 months, the
devices corresponding to FIG. 37B were tuned to provide maximal
delivery rates at approximately 1 year.
[0682] Example C: Measured release rate profiles for Ranibizumab
(Lucentis.TM.) formulations of 40 and 100 mg/mL from therapeutic
devices and porous titanium frit structures corresponding to a
device half life of 100 days
[0683] Therapeutic devices having stainless steel porous frit
structures and formulations were prepared in accordance with
Examples A and B. The devices had volumes of 25 uL and an RRI of
0.02.
[0684] Pressure decay tests of the assembled porous frit structures
were conducted as described herein.
[0685] Eighteen devices were injected with the 100 mg/mL
formulation and 18 devices were injected with the 40 mg/mL
formulation. However, measurements of some devices were stopped for
other assays every 4 months so only 6 devices for each formulation
have release data through 180 days. The rate of release was
measured for 16 weeks, and the amount release after each 2 week
interval determined. These data show extended release of
therapeutic amounts to 16 weeks for each of the 100 mg/mL and 40
mg/mL formulations. The data indicates a measured rate of 3.5 and
8.1 ug/day at 15 weeks, for the 40 and 100 mg/mL formulation
injections, respectively.
[0686] FIG. 37C shows release of ranibizumab from a population of
devices receiving injections of 40 mg/mL formulation and 100 mg/mL
formulation.
[0687] The data of FIGS. 37A to 37C show that the therapeutic agent
comprising ranibizumab can be released from the therapeutic devices
in accordance with the teachings as described herein, for example
with reference to FIGS. 32A-32D, 36A-36D and Tables WW, X, YY, for
example.
[0688] As used herein, like identifiers denote like structural
elements and/or steps.
[0689] Any structure or combination of structures or method steps
or components or combinations thereof as described herein can be
combined in accordance with embodiments as described herein, based
on the knowledge of one of ordinary skill in the art and teachings
described herein. In addition, any structure or combination of
structures or method steps or components or combinations thereof as
described herein may be specifically excluded from any embodiments,
based on the knowledge of one of ordinary skill in the art and the
teachings described herein.
[0690] While the exemplary embodiments have been described in some
detail, by way of example and for clarity of understanding, those
of skill in the art will recognize that a variety of modifications,
adaptations, and changes may be employed. Hence, the scope of the
present invention should be limited solely by the appended
claims.
TABLE-US-00036 TABLE 1A Therapeutic Agent List Brands Molecular
Generic Name (Companies) Category Indication Weight
2-Methoxyestradiol (Paloma Angiogenesis AMD analogs
Pharmaceuticals) inhibitors 3-aminothalidomide 13-cis retinoic acid
Accutane TM (Roche Pharmaceuticals) A0003 (Aqumen A0003 AMD
BioPharmaceuticals) A5b1 integrin (Jerini Ophthalmic); Inhibitors
of a5b1 AMD inhibitor (Ophthotech) integrin Abarelix Plenaxis .TM.
(Praecis Anti-Testosterone For palliative treatment 37731
Pharmaceuticals) Agents; of advanced prostate Antineoplastic
cancer. Agents Abatacept Orencia .TM. (Bristol- Antirheumatic For
the second line 37697 Myers Squibb) Agents reduction of the signs
and symptoms of moderate-to-severe active rheumatoid arthritis,
inducing inducing major clinical response, slowing the progression
of structural damage, and improving physical function in adult
patients who have Abciximab ReoPro .TM.; ReoPro .TM.
Anticoagulants; For treatment of 42632 (Centocor) Antiplatelet
Agents myocardial infarction, adjunct to percutaneous 177oronary
intervention, unstable angina ABT-578 (Abbott Laboratories) Limus
Immunophilin Binding Compounds Acetonide Adalimumab Humira .TM.
(Abbott Antirheumatic Uveitis, AMD 25645 Laboratories) Agents;
Immunomodulatory Agents Aldesleukin Proleukin .TM.; Antineoplastic
For treatment of adults 61118 Proleukin .TM. (Chiron Agents with
metastatic renal Corp) cell carcinoma Alefacept Amevive .TM.
Immunomodulatory For treatment of 42632 Agents; moderate to severe
Immunosuppressive chronic plaque Agents psoriasis Alemtuzumab
Campath .TM.; Antineoplastic For treatment of 6614 Campath .TM.
(ILEX Agents B-cell Pharmaceuticals chronic lymphocytic LP);
MabCampath .TM. leukemia Alpha-1-proteinase Aralast .TM. (Baxter);
Enzyme For treatment of 28518 inhibitor Prolastin .TM. (Talecris
Replacement panacinar emphysema Biotherapeutics C Agents formerly
Bayer) Alteplase Activase .TM. Thrombolytic For management of 54732
(Genentech Inc) Agents acute myocardial infarction, acute ischemic
strok and for lysis of acute pulmonary emboli AMG-1470 Anakinra
Kineret .TM. (Amgen Anti-Inflammatory For the treatment of 65403
Inc) Agents, Non- adult rheumatoid Steroidal; arthritis.
Antirheumatic Agents; Immunomodulatory Agents Anecortave acetate
Angiostatin Anistreplase Eminase .TM. (Wulfing Thrombolytic For
lysis of acute 54732 Pharma GmbH) Agents pulmonary emboli,
intracoronary emboli and management of myocardial infarction
Anti-angiogenesis (Eyecopharm) Anti-angiogenesis AMD peptides
peptides Anti-angiogenesis (TRACON Pharma) Anti-angiogenesis AMD
antibodies, antibodies TRC093, TRC105 Anti-angiogeric Icon-1 .TM.
(Iconic Anti-angiogeric AMD bifunctional protein Therapeutics)
bifunctional protein, Icon-1 Anti-endothelial growth factor
Antihemophilic Advate .TM.; Coagulants; For the treatment of 70037
Factor Alphanate .TM.; Thrombotic Agents hemophilia A, von Bioclate
.TM.; Willebrand diseae and Helixate .TM.; Helixate Factor XIII
deficiency FS .TM.; Hemofil M .TM.; Humate-P .TM.; Hyate: C .TM.;
Koate- HP .TM.; Kogenate .TM.; Kogenate FS .TM.; Monarc-M .TM.;
Monoclate-P .TM.; ReFacto .TM.; Xyntha .TM. Antithymocyte Genzyme);
Immunomodulatory For prevention of renal 37173 globulin
Thymoglobulin .TM. Agents transplant rejection (SangStat Medical
Anti-hypertensive (MacuCLEAR) Anti-hypertensive AMD MC1101 MC1101
Anti-platelet devired growth factor Anti-VEGF (Neurotech);
Anti-VEGF AMD Avastin .TM. (NeoVista) AP23841 (Ariad) Limus
Immunophilin Binding Compounds ARC1905 Ophthotech Complement
Cascade Inhibitor (Factor C5) Aprotinin Trasylol .TM.
Antifibrinolytic For prophylactic use to 90569 Agents reduce
perioperative blood loss and the need for blood transfusion in
patients undergoing cardiopulmonary bypass in the course of
coronary artery bypass graft surgery who are at an increased risk
for blood loss and blood transfusio Arcitumomab CEA-Scan .TM.
Diagnostic Agents; For imaging colorectal 57561 Imaging Agents
tumors Asparaginase Elspar .TM. (Merck & Antineoplastic For
treatment of acute 132.118 Co. Inc) Agents lympocytic leukemia and
non-Hodgkins lymphoma Axitinib Tyrosine Kinase 386 Inhibitors
Basiliximab Simulect .TM. (Novartis Immunomodulatory For
prophylactic 61118 Pharmaceuticals) Agents; treatment of kidney
Immunosuppressive transplant rejection Agents Becaplermin Regranex
.TM.; Anti-Ulcer Agents; For topical treatment of 123969 Regranex
.TM. (OMJ Topical skin ulcers (from Pharmaceuticals) diabetes)
Bevacizumab Avastin .TM.; Avastin .TM. Antiangiogenesis For
treatment of 27043 (Genentech Inc) Agents; metastatic colorectal
Antineoplastic cancer Agents Bivalirudin Angiomax .TM.;
Anticoagulants; For treatment of 70037 Angiomax .TM. Antithrombotic
heparin-induced (Medicines Co or Agents thrombocytopenia MDCO);
Angiox .TM. Bortezomib Proteosome Inhibitors Bosutinib Tyrosine
Kinase 530 Inhibitors Botulinum Toxin BOTOX .TM. (Allegran
Anti-Wrinkle For the treatment of 23315 Type A Inc); BOTOX Agents;
cervical dystonia in Cosmetic .TM. (Allegran Antidystonic adults to
decrease the Inc); Botox .TM.; Agents; severity of abnormal Dysport
.TM. Neuromuscular head position and neck Blocking Agents pain
associated with cervical dystonia. Also for the treatment of severe
primary axillary hyperhidrosis that is inadequately managed with
topical Botulinum Toxin Myobloc .TM. (Solstice Antidystonic Agents
For the treatment of 12902 Type B Neurosciences); patients with
cervical Neurobloc .TM. dystonia to reduce the (Solstice severity
of abnormal Neurosciences) head position and neck pain associated
with cervical dystonia. C5 inhibitor (Jerini Ophthalmic);
Inhibitors of C5 AMD (Ophthotech) Cal101 Calistoga PI3Kdelta
Inhibitor AMD, DME Canstatin Capromab ProstaScint .TM. Imaging
Agents For diagnosis of 84331 (Cytogen Corp) prostate cancer and
detection of intra-pelvic metastases Captopril ACE Inhibitors
CCI-779 (Wyeth) Limus Immunophilin Binding Compounds Cediranib
Tyrosine Kinase 450 Inhibitors Celecoxib Cyclooxygenase Inhibitors
Cetrorelix Cetrotide .TM. Hormone For the inhibition of 78617
Antagonists; premature LH surges in Infertility Agents women
undergoing controlled ovarian stimulation Cetuximab Erbitux .TM.;
Erbitux .TM. Antineoplastic For treatment of 42632 (ImClone Systems
Agents metastatic colorectal Inc) cancer. Choriogonadotropin
Novarel .TM.; Ovidrel .TM.; Fertility Agents; For the treatment of
78617 alfa Pregnyl .TM.; Profasi .TM. Gonadotropins female
infertility Cilary neurotrophic (Neurotech) Cilary neurotrophic AMD
factor factor Coagulation Factor Benefix .TM. (Genetics Coagulants;
For treatment of 267012 IX Institute) Thrombotic Agents hemophilia
(Christmas disease). Coagulation factor NovoSeven .TM. (Novo
Coagulants; For treatment of 54732 VIIa Nordisk) Thrombotic Agents
hemorrhagic complications in hemophilia A and B Colchicines
Collagenase Cordase .TM.; Santyl .TM. Anti-Ulcer Agents; For
treatment of chronic 138885 (Advance Topical dermal ulcers and
Biofactures Corp); severe skin burns Xiaflextm .TM. Complement
factor (Optherion); (Taligen Complement factor AMD, Geographic H
recombinant Therapeutics) H recombinant Atrophy Compstatin
(Potentia Complement Factor AMD derivative peptide,
Pharmaceuticals) C3 Inhibitors; POT-4 Compstatin Derivative
Peptides Corticotropin ACTH .TM.; Diagnostic Agents For use as a
diagnostic 33927 Acethropan .TM.; agent in the screening Acortan
.TM.; Acthar .TM.; of patients presumed to Exacthin .TM.; H. P.
have adrenocortical Acthar Gel .TM.; insufficiency. Isactid .TM.;
Purified cortrophin gel .TM.; Reacthin .TM.; Solacthyl .TM.; Tubex
Cosyntropin Cortrosyn .TM.; Diagnostic Agents For use as a
diagnostic 33927 Synacthen depot .TM. agent in the screening
of patients presumed to have adrenocortical insufficiency.
Cyclophilins Limus Immunophilin Binding Compounds Cyclosporine
Gengraf .TM. (Abbott Antifungal Agents; For treatment of 32953
labs); Neoral .TM. Antirheumatic transplant rejection, (Novartis);
Agents; rheumatoid arthritis, Restasis .TM.; Dermatologic severe
psoriasis Restasis .TM. (Allergan Agents; Enzyme Inc); Sandimmune
.TM. Inhibitors; (Novartis); Immunomodulatory Sangcya .TM. Agents;
Immunosuppressive Agents Daclizumab Zenapax .TM. Immunomodulatory
For prevention of renal 61118 (Hoffmann-La Roche Agents; transplant
rejection; Inc) Immunosuppressive Uveitis Agents Darbepoetin alfa
Aranesp .TM. (Amgen Antianemic Agents For the treatment of 55066
Inc.) anemia (from renal transplants or certain HIV treatment)
Dasatinib Tyrosine Kinase 488 Inhibitors Defibrotide Dasovas .TM.;
Antithrombotic Defibrotide is used to 36512 Noravid .TM.; Agents
treat or prevent a failure Prociclide .TM. of normal blood flow
(occlusive venous disease, OVD) in the liver of patients who have
had bone marrow transplants or received certain drugs such as oral
estrogens, mercaptopurine, and many others. Denileukin diftitox
Ontak .TM. Antineoplastic For treatment of 61118 Agents cutaneous
T-cell lymphoma Desmopressin Adiuretin .TM.; Antidiuretic Agents;
For the management of 46800 Concentraid .TM.; Hemostatics; Renal
primary nocturnal Stimate .TM. Agents enuresis and indicated as
antidiuretic replacement therapy in the management of central
diabetes insipidus and for the management of the temporary polyuria
and polydipsia following head trauma or surgery in the pitu
Dexamethasone Ozurdex .TM. (Allergan) Glucocorticoid DME,
inflammation, 392 macular edema following branch retinal vein
occlusion (BRVO) or central retinal vein occlusion (CRVO)
Diclofenac Cyclooxygenase Inhibitors Dithiocarbamate NF.kappa.B
Inhibitor Dornase Alfa Dilor .TM.; Dilor-400 .TM.; Enzyme For the
treatment of 7656 (double Lufyllin .TM.; Lufyllin- Replacement
cystic fibrosis. strand) 400 .TM.; Neothylline .TM.; Agents
Pulmozyme .TM. (Genentech Inc) Drotrecogin alfa Xigris .TM.; Xigris
.TM. (Eli Antisepsis Agents For treatment of severe 267012 Lilly
& Co) sepsis Eculizumab Soliris .TM.; Soliris .TM. Complement
AMD 188333 (Alexion Cascade Inhibitor Pharmaceuticals) (Factor C5)
Efalizumab Raptiva .TM.; Raptiva .TM. Immunomodulatory For the
treatment of 128771 (Genentech Inc) Agents; adult patients with
Immunosuppressive moderate to severe Agents chronic plaque
psoriasis, who are candidates for phototherapy or systemic therapy.
Endostatin Enfuvirtide Fuzeon .TM.; Fuzeon .TM. Anti-HIV Agents;
For treatment of HIV 16768 (Roche HIV Fusion AIDS Pharmaceuticals)
Inhibitors Epoetin alfa Epogen .TM. (Amgen Antianemic Agents For
treatment of 55066 Inc.); Epogin .TM. anemia (from renal (Chugai);
Epomax .TM. transplants or certain (Elanex); Eprex .TM. HIV
treatment) (Janssen-Cilag. Ortho Biologics LLC); NeoRecormon .TM.
(Roche); Procrit .TM. (Ortho Biotech); Recormon .TM. (Roche)
Eptifibatide Integrilin .TM.; Anticoagulants; For treatment of 7128
Integrilin .TM. Antiplatelet Agents; myocardial infarction
(Millennium Pharm) Platelet and acute coronary Aggregation
syndrome. Inhibitors Erlotinib Tyrosine Kinase 393 Inhibitors
Etanercept Enbrel .TM.; Enbrel .TM. Antirheumatic Uveitis, AMD
25645 (Immunex Corp) Agents; Immunomodulatory Agents Everolimus
Novartis Limus Immunophilin AMD Binding Compounds, mTOR Exenatide
Byetta .TM.; Byetta .TM. Indicated as adjunctive 53060 (Amylin/Eli
Lilly) therapy to improve glycemic control in patients with Type 2
diabetes mellitus who are taking metformin, a sulfonylurea, or a
combination of both, but have not achieved adequate glycemic
control. FCFD4514S Genentech/Roche Complement AMD, Geographic
Cascade Inhibitor Atrophy (Factor D) Felypressin Felipresina .TM.
[INN- Renal Agents; For use as an 46800 Spanish]; Vasoconstrictor
alternative to Felipressina .TM. Agents adrenaline as a [DCIT];
186ocalizing agent, Felypressin .TM. provided that local
[USAN:BAN:INN]; ischaemia is not Felypressine .TM. [INN- essential.
French]; Felypressinum .TM. [INN-Latin]; Octapressin .TM.
Fenretinide Sirion/reVision Binding Protein AMD, Geographic
Therapeutics Antagonist for Oral Atrophy Vitamin A Filgrastim
Neupogen .TM. (Amgen Anti-Infective Increases leukocyte 28518 Inc.)
Agents; production, for Antineutropenic treatment in non- Agents;
myeloid Immunomodulatory cancer, neutropenia and Agents bone marrow
transplant FK605-binding Limus Immunophilin proteins, FKBPs Binding
Compounds Fluocinolone Retisert .TM. (Bausch & Glucocorticoid
Retinal inflammation, 453 Acetonide Lomb); Iluvien .TM. diabetic
macular edema (Alimera Sciences, Inc.) Follitropin beta Follistim
.TM. Fertility Agents For treatment of female 78296 (Organon);
Gonal infertility F .TM.; Gonal-F .TM. Fumagillin Galsulfase
Naglazyme .TM.; Enzyme For the treatment of 47047 Naglazyme .TM.
Replacement adults and children with (BioMarin Agents
Mucopolysaccharidosis Pharmaceuticals) VI. Gefitinib Tyrosine
Kinase 447 Inhibitors Gemtuzumab Mylotarg .TM.; Antineoplastic For
treatment of acute 39826 ozogamicin Mylotarg .TM. (Wyeth) Agents
myeloid leukemia Glatiramer Acetate Copaxone .TM. Adjuvants, For
reduction of the 29914 Immunologic; frequency of relapses in
Immunosuppressive patients with Relapsing- Agents Remitting
Multiple Sclerosis. Glucagon GlucaGen .TM. (Novo Antihypoglycemic
For treatment of severe 54009 recombinant Nordisk); Agents
hypoglycemia, also Glucagon .TM. (Eli Lilly) used in
gastrointestinal imaging Goserelin Zoladex .TM. Antineoplastic
Breast cancer; Prostate 78617 Agents; carcinoma; Antineoplastic
Endometriosis Agents, Hormonal Human Serum Albutein .TM. (Alpha
Serum substitutes For treatment of severe 39000 Albumin Therapeutic
Corp) blood loss, hypervolemia, hypoproteinemia Hyaluronidase
Vitragan .TM.; Anesthetic For increase of 69367 Vitrase .TM.;
Vitrase .TM. Adjuvants; absorption and (Ista Pharma) Permeabilizing
distribution of other Agents injected drugs and for rehydration
Ibritumomab Zevalin .TM. (IDEC Antineoplastic For treatment of non-
33078 Pharmaceuticals) Agents Hodgkin's lymphoma Idursulfase
Elaprase .TM. (Shire Enzyme For the treatment of 47047
Pharmaceuticals) Replacement Hunter syndrome in Agents adults and
children ages 5 and older. Imatinib Tyrosine Kinase AMD, DME 494
Inhibitors Immune globulin Civacir .TM.; Anti-Infectives; For
treatment of 42632 Flebogamma .TM. Immunomodulatory
immunodeficiencies, (Instituto Grifols SA); Agents thrombocytopenic
Gamunex .TM. (Talecris purpura, Kawasaki Biotherapeutics) disease,
gammablobulinemia, leukemia, bone transplant Infliximab Remicade
.TM. Immunomodulatory Uveitis, AMD 25645 (Centocor Inc) Agents;
Immunosuppressive Agents Insulin Glargine Lantus .TM. Hypoglycemic
For treatment of 156308 recombinant Agents diabetes (type I and II)
Insulin Lyspro Humalog .TM. (Eli Lily); Hypoglycemic For treatment
of 154795 recombinant Insulin Lispro (Eli Agents diabetes (type I
and II) Lily) Insulin recombinant Novolin R .TM. (Novo Hypoglycemic
For treatment of 156308 Nordisk) Agents diabetes (type I and II)
Insulin, porcine Iletin II .TM. Hypoglycemic For the treatment of
156308 Agents diabetes (type I and II) Interferon Interferon
Alfa-2a, Roferon A .TM. Antineoplastic For treatment of chronic
57759 Recombinant (Hoffmann-La Roche Agents; Antiviral hepatitis C,
hairy cell Inc); Veldona .TM. Agents leukemia, AIDS-related
(Amarillo Kaposi's sarcoma, and Biosciences) chronic myelogenous
leukemia. Also for the treatment of oral warts arising from HIV
infection. Interferon Alfa-2b, Intron A .TM. (Schering
Antineoplastic For the treatment of 57759 Recombinant Corp) Agents;
Antiviral hairy cell leukemia, Agents; malignant melanoma,
Immunomodulatory and AIDS-related Agents Kaposi's sarcoma.
Interferon alfacon-1 Advaferon .TM.; Antineoplastic For treatment
of hairy 57759 Infergen .TM. Agents; Antiviral cell leukemia,
(InterMune Inc) Agents; malignant melanoma, Immunomodulatory and
AIDS-related Agents Kaposi's sarcoma Interferon alfa-n1 Wellferon
.TM. Antiviral Agents; For treatment of 57759
(GlaxoSmithKline) Immunomodulatory venereal or genital Agents warts
caused by the Human Papiloma Virus Interferon alfa-n3 Alferon .TM.
(Interferon Antineoplastic For the intralesional 57759 Sciences
Inc.); Agents; Antiviral treatment of refractory Alferon LDO .TM.;
Agents; or recurring external Alferon N Injection .TM.
Immunomodulatory condylomata Agents 189cuminate. Interferon beta-1b
Betaseron .TM. (Chiron Antiviral Agents; For treatment of 57759
Corp) Immunomodulatory relapsing/remitting Agents multiple
sclerosis Interferon gamma-1b Actimmune .TM.; Antiviral Agents; For
treatment of 37835 Actimmune .TM. Immunomodulatory Chronic
granulomatous (InterMune Inc) Agents disease, Osteopetrosis
Lapatinib Tyrosine Kinase 581 Inhibitors Lepirudin Refludan .TM.
Anticoagulants; For the treatment of 70037 Antithrombotic
heparin-induced Agents; Fibrinolytic thrombocytopenia Agents
Lestaurtinib Tyrosine Kinase 439 Inhibitors Leuprolide Eligard .TM.
(Atrix Anti-Estrogen For treatment of 37731 Labs/QLT Inc) Agents;
prostate cancer, Antineoplastic endometriosis, uterine Agents
fibroids and premature puberty Lutropin alfa Luveris .TM. (Serono)
Fertility Agents For treatment of female 78617 infertility
Mecasermin Increlex .TM.; For the long-term 154795 Increlex .TM.
(Tercica); treatment of growth Iplex failure in pediatric patients
with Primary IGFD or with GH gene deletion who have developed
neutralizing antibodies to GH. It is not indicated to treat
Secondary IGFD resulting from GH deficiency, malnutrition, hypoth
Menotropins Repronex .TM. Fertility Agents For treatment of female
78617 infertility Methotrexate Immunomodulatory Uveitis, DME mTOR
inhibitors Muromonab Orthoclone OKT3 .TM. Immunomodulatory For
treatment of organ 23148 (Ortho Biotech) Agents; transplant
recipients, Immunosuppressive prevention of organ Agents rejection
Natalizumab Tysabri .TM. Immunomodulatory For treatment of 115334
Agents multiple sclerosis. Nepafenac Cyclooxygenase Inhibitors
Nesiritide Natrecor .TM. Cardiac drugs For the intravenous 118921
treatment of patients with acutely decompensated congestive heart
failure who have dyspnea at rest or with minimal activity.
Nilotinib Tyrosine Kinase 530 Inhibitors NS398 Cyclooxygenase
Inhibitors Octreotide Atrigel .TM.; Anabolic Agents; For treatment
of 42687 Longastatin .TM.; Antineoplastic acromegaly and
Sandostatin .TM.; Agents, Hormonal; reduction of side effects
Sandostatin LAR .TM.; Gastrointestinal from cancer Sandostatin LAR
.TM. Agents; Hormone chemotherapy (Novartis) Replacement Agents
Omalizumab Xolair .TM. (Genentech Anti-Asthmatic For treatment of
29596 Inc) Agents; asthma caused by Immunomodulatory allergies
Agents Oprelvekin Neumega .TM.; Coagulants; Increases reduced 45223
Neumega .TM. Thrombotics platelet levels due to (Genetics Institute
chemotherapy Inc) OspA lipoprotein LYMErix .TM. Vaccines For
prophylactic 95348 (SmithKline treatment of Lyme Beecham) Disease
OT-551 (Othera) Anti-oxidant AMD eyedrop Oxytocin Oxytocin .TM.
(BAM Anti-tocolytic To assist in labor, 12722 Biotech); Pitocin
.TM. Agents; Labor elective labor induction, (Parke-Davis);
Induction Agents; uterine contraction Syntocinon .TM. Oxytocics
induction (Sandoz) Palifermin Kepivance .TM. (Amgen Antimucositis
For treatment of 138885 Inc) Agents mucositis (mouth sores)
Palivizumab Synagis .TM. Antiviral Agents For treatment of 63689
respiratory diseases casued by respiratory syncytial virus
Panitumumab Vectibix .TM.; Antineoplastic For the treatment of
134279 Vectibix .TM. (Amgen) Agents EGFR-expressing, metastatic
colorectal carcinoma with disease progression on or following
fluoropyrimidine-, oxaliplatin-, and irinotecan- containing
chemotherapy regimens. PDGF inhibitor (Jerini Ophthalmic);
Inhibitors of PDGF AMD (Ophthotech) PEDF (pigment epithelium
derived factor) Pegademase Adagen .TM. (Enzon Enzyme For treatment
of 36512 bovine Inc.) Replacement adenosine deaminase Agents
deficiency Pegaptanib Macugen .TM. Oligonucleotide For the
treatment of 103121 neovascular (wet) age- related macular
degeneration. Pegaspargase Oncaspar .TM. (Enzon Antineoplastic For
treatment of acute 132.118 Inc) Agents lymphoblastic leukemia
Pegfilgrastim Neulasta .TM. (Amgen Anti-Infective Increases
leukocyte 28518 Inc.) Agents; production, for Antineutropenic
treatment in non- Agents; myeloid cancer, Immunomodulatory
neutropenia and bone Agents marrow transplant Peginterferon Pegasys
.TM. Antineoplastic For treatment of hairy 57759 alfa-2a
(Hoffman-La Roche Agents; Antiviral cell leukemia, Inc) Agents;
malignant melanoma, Immunomodulatory and AIDS-related Agents
Kaposi's sarcoma. Peginterferon PEG-Intron Antineoplastic For the
treatment of 57759 alfa-2b (Schering Corp); Agents; Antiviral
chronic hepatitis C in Unitron PEG .TM. Agents; patients not
previously Immunomodulatory treated with interferon Agents alpha
who have compensated liver disease and are at least 18 years of
age. Pegvisomant Somavert .TM. (Pfizer Anabolic Agents; For
treatment of 71500 Inc) Hormone acromegaly Replacement Agents
Pentoxifylline Perindozril ACE Inhibitors Pimecrolimus Limus
Immunophilin Binding Compounds PKC (protein kinase C) inhibitors
POT-4 Potentia/Alcon Complement AMD Cascade Inhibitor (Factor C3)
Pramlintide Symlin .TM.; Symlin .TM. For the mealtime 16988 (Amylin
treatment of Type I and Pharmaceuticals) Type II diabetes in
combination with standard insulin therapy, in patients who have
failed to achieve adequate glucose control on insulin monotherapy.
Proteosome Velcade .TM. Proteosome inhibitors inhibitors
Pyrrolidine Quinopril ACE Inhibitors Ranibizumab Lucentis .TM. For
the treatment of 27043 patients with neovascular (wet) age- related
macular degeneration. Rapamycin (MacuSight) Limus Immunophilin AMD
(siroliums) Binding Compounds Rasburicase Elitek .TM.; Elitek .TM.
Antihyperuricemic For treatment of 168.11 (Sanofi-Synthelabo Agents
hyperuricemia, reduces Inc); Fasturtec .TM. elevated plasma uric
acid levels (from chemotherapy) Reteplase Retavase .TM.
Thrombolytic For lysis of acute 54732 (Centocor); Agents pulmonary
emboli, Retavase (Roche) intracoronary emboli and management of
myocardial infarction Retinal stimulant Neurosolve .TM. Retinal
stimulants AMD (Vitreoretinal Technologies) Retinoid(s) Rituximab
MabThera .TM.; Antineoplastic For treatment of B-cell 33078 Rituxan
.TM. Agents non-Hodgkins lymphoma (CD20 positive) RNAI (RNA
interference of angiogenic factors) Rofecoxib Vioxx .TM.; Ceoxx
.TM.; Cyclooxygenase Ceeoxx .TM. (Merck & Inhibitors Co.)
Rosiglitazone Thiazolidinediones Ruboxistaurin Eli Lilly Protein
Kinase C DME, diabetic 469 (PKC)-b Inhibitor peripheral retinopathy
Salmon Calcitonin Calcimar .TM.; Antihypocalcemic For the treatment
of 57304 Miacalcin .TM. Agents; post-menopausal (Novartis)
Antiosteporotic osteoporosis Agents; Bone Density Conservation
Agents Sargramostim Immunex .TM.; Anti-Infective For the treatment
of 46207 Leucomax .TM. Agents; cancer and bone (Novartis);
Antineoplastic marrow transplant Leukine .TM.; Agents; Leukine .TM.
(Berlex Immunomodulatory Laboratories Inc) Agents SAR 1118 SARCode
Immunomodulatory Dry eye, DME, Agent conjunctivitis SDZ-RAD Limus
Immunophilin Binding Compounds Secretin SecreFlo .TM.; Diagnostic
Agents For diagnosis of 50207 Secremax .TM., pancreatic exocrine
SecreFlo .TM. dysfunction and (Repligen Corp) gastrinoma Selective
inhibitor of the factor 3 complement cascade Selective inhibitor of
the factor 5 complement cascade Semaxanib Tyrosine Kinase 238
Inhibitors Sermorelin Geref .TM. (Serono Anabolic Agents; For the
treatment of 47402 Pharma) Hormone dwarfism, prevention of
Replacement HIV-induced weight Agents loss Serum albumin Megatope
.TM. (IsoTex Imaging Agents For determination of
39000 iodinated Diagnostics) total blood and plasma volumes SF1126
Semafore PI3k/mTOR AMD, DME Inhibition Sirolimus (MacuSight) Limus
Immunophilin AMD reformulation Binding (rapamycin) Compounds siRNA
molecule (Quark siRNA molecule AMD synthetic, FTP- Pharmaceuticals)
synthetic 801i-14 Somatropin BioTropin .TM. (Biotech Anabolic
Agents; For treatment of 71500 recombinant General); Hormone
dwarfism, acromegaly Genotropin .TM. Replacement and prevention of
HIV- (Pfizer); Agents induced weight loss Humatrope .TM. (Eli
Lilly); Norditropin .TM. (Novo Nordisk); Nutropin .TM. (Genentech
Inc.); NutropinAQ .TM. (Genentech Inc.); Protropin .TM. (Genentech
Inc.); Saizen .TM. (Serono SA); Serostim .TM.; Serostim .TM.
(Serono SA); Tev-Tropin .TM. (GATE) Squalamine Streptokinase
Streptase .TM. (Aventis Thrombolytic For the treatment of 90569
Behringer GmbH) Agents acute evolving transmural myocardial
infarction, pulmonary embolism, deep vein thrombosis, arterial
thrombosis or embolism and occlusion of arteriovenous cannulae
Sunitinib Tyrosine Kinase 398 Inhibitors TA106 Taligen Complement
AMD Cascade Inhibitor (Factor B) Tacrolimus Limus Immunophilin
Binding Compounds Tenecteplase TNKase .TM. Thrombolytic For
treatment of 54732 (Genentech Inc) Agents myocardial infarction and
lysis of intracoronary emboli Teriparatide Apthela .TM.; Bone
Density For the treatment of 66361 Forsteo .TM.; Forteo .TM.;
Conservation osteoporosis in men Fortessa .TM.; Agents and
postmenopausal Opthia .TM.; Optia .TM.; women who are at high
Optiah .TM.; Zalectra .TM.; risk for having a Zelletra .TM.
fracture. Also used to increase bone mass in men with primary or
hypogonadal osteoporosis who are at high risk for fracture.
Tetrathiomolybdate Thalidomide Celgene Anti-inflammatory, Uveitis
Anti-proliferative Thyrotropin Alfa Thyrogen .TM. Diagnostic Agents
For detection of 86831 (Genzyme Inc) residueal or recurrent thyroid
cancer Tie-1 and Tie-2 kinase inhibitors Toceranib Tyrosine Kinase
396 Inhibitors Tositumomab Bexxar .TM. (Corixa Antineoplastic For
treatment of non- 33078 Corp) Agents Hodgkin's lymphoma (CD20
positive, follicular) TPN 470 analogue Trastuzumab Herceptin .TM.
Antineoplastic For treatment of HER2- 137912 (Genentech) Agents
positive pulmonary breast cancer Triamcinolone Triesence .TM.
Glucocorticoid DME, For treatment of 435 acetonide inflammation of
the retina Troglitazone Thiazolidinediones Tumistatin
Urofollitropin Fertinex .TM. (Serono Fertility Agents For treatment
of female 78296 S.A.) infertility Urokinase Abbokinase .TM.;
Thrombolytic For the treatment of 90569 Abbokinase .TM. Agents
198ulmonary embolism, (Abbott Laboratories) coronary artery
thrombosis and IV catheter clearance Vandetanib Tyrosine Kinase 475
Inhibitors Vasopressin Pitressin .TM.; Antidiuretics; For the
treatment of 46800 Pressyn .TM. Oxytocics; enuresis, polyuria,
Vasoconstrictor diabetes insipidus, Agents polydipsia and
oesophageal varices with bleeding Vatalanib Tyrosine Kinase 347
Inhibitors VEGF receptor kinase inhibitor VEGF Trap Aflibercept
.TM. Genetically DME, cancer, retinal 96600 (Regneron Engineered
vein occlusion, Pharmaceuticals, Antibodies choroidal Bayer
HealthCare neovascularization, AG) delay wound healing, cancer
treatment Visual Cycle (Acucela) Visual Cycle AMD Modulator
ACU-4229 Modulator Vitamin(s) Vitronectin receptor antagonists
Volociximab Ophthotech alpha5beta1 AMD Integrin Inhibitor XL765
Exelixis/Sanofi- PI3k/mTOR AMD, DME Aventis Inhibition
* * * * *
References