U.S. patent application number 10/198903 was filed with the patent office on 2003-05-29 for articles of manufacture.
This patent application is currently assigned to Lilly ICOS LLC. Invention is credited to Emmick, Jeffrey T., Ferguson, Kenneth M., Pullman, William E., Whitaker, John S..
Application Number | 20030100478 10/198903 |
Document ID | / |
Family ID | 24231497 |
Filed Date | 2003-05-29 |
United States Patent
Application |
20030100478 |
Kind Code |
A1 |
Emmick, Jeffrey T. ; et
al. |
May 29, 2003 |
Articles of manufacture
Abstract
The present invention relates to highly selective
phosphodiesterase (PDE) enzyme inhibitors and to their use in
pharmaceutical articles of manufacture. In particular, the present
invention relates to potent inhibitors of cyclic guanosine
3',5'-monophosphate specific phosphodiesterase type 5 (PDE5) that
when incorporated into a pharmaceutical product at about 1 to about
20 mg unit dosage are useful for the treatment of sexual
dysfunction. The articles of manufacture described herein are
characterized by selective PDE5 inhibition, and accordingly,
provide a benefit in therapeutic areas where inhibition of PDE5 is
desired, with minimization or elimination of adverse side effects
resulting from inhibition of other phosphodiesterase enzymes.
Inventors: |
Emmick, Jeffrey T.;
(Plainfield, IN) ; Ferguson, Kenneth M.; (Bothell,
WA) ; Pullman, William E.; (Far Hills, NJ) ;
Whitaker, John S.; (Woodinville, WA) |
Correspondence
Address: |
MARSHALL, GERSTEIN & BORUN
6300 SEARS TOWER
233 SOUTH WACKER
CHICAGO
IL
60606-6357
US
|
Assignee: |
Lilly ICOS LLC
|
Family ID: |
24231497 |
Appl. No.: |
10/198903 |
Filed: |
July 19, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10198903 |
Jul 19, 2002 |
|
|
|
09558911 |
Apr 26, 2000 |
|
|
|
6451807 |
|
|
|
|
60132036 |
Apr 30, 1999 |
|
|
|
Current U.S.
Class: |
514/1 ;
514/252.16 |
Current CPC
Class: |
A61K 31/00 20130101;
A61P 15/10 20180101; A61K 31/52 20130101; A61P 43/00 20180101; A61K
31/4985 20130101; A61K 31/505 20130101 |
Class at
Publication: |
514/1 ;
514/252.16 |
International
Class: |
A61K 031/496; A61K
031/00 |
Claims
What is claimed is:
1. An article of manufacture for human pharmaceutical use
comprising: (a) an oral dosage form comprising about 1 to about 20
mg of a selective PDE5 inhibitor having (i) at least a 100 fold
differential in IC.sub.50 values for the inhibition of PDE5 versus
PDE6, (ii) at least a 1000 fold differential in IC.sub.50 values
for the inhibition of PDE5 versus PDE1c, (iii) an IC.sub.50 for the
inhibition of PDE5 less than 10 nM, and (iv) sufficient
bioavailability to be effective in about 1 to about 20 mg unit oral
dosages; (b) a package insert providing that the PDE5 inhibitor is
useful to treat sexual dysfunction in a patient in need thereof,
and that is free of contradictions associated with administration
of organic nitrates; and (c) a container.
2. An article of manufacture for human pharmaceutical use
comprising: (a) an oral dosage form comprising about 1 to about 20
mg of selective PDE5 inhibitor having (i) at least a 100 fold
differential in IC.sub.50 values for the inhibition of PDE5 versus
PDE6, (ii) at least a 1000 fold differential in IC.sub.50 values
for the inhibition of PDE5 versus PDE1c, (iii) an IC.sub.50 less
than 10 nM, and (iv) a sufficient bioavailability to be effective
in about 1 to about 20 mg unit oral dosages; (b) a package insert
providing that the PDE5 inhibitor is useful to treat sexual
dysfunction in a patient in need thereof and that is using an
organic nitrate; and (c) a container.
3. An article of manufacture for human pharmaceutical use
comprising: (a) an oral dosage form comprising about 1 to about 20
mg of a selective PDE5 inhibitor having (i) at least a 100 fold
differential in IC.sub.50 values for the inhibition of PDE5 versus
PDE6, (ii) at least 1000 fold differential in IC.sub.50 values for
the inhibition of PDE5 versus PDE1c, (iii) an IC.sub.50 less than
10 nM, and (iv) a sufficient bioavailability to be effective in
about 1 to about 20 mg unit oral dosages; (b) a package insert
providing that the PDE5 inhibitor is useful to treat sexual
dysfunction in a patient in need thereof and that is suffering from
a condition selected from the group consisting of a retinal
disease, proneness to flushing, proneness to vision abnormalities,
class 1 congestive heart failure, a myocardial infarction 90 days
or more before onset of the sexual dysfunction treatment, and
combinations thereof; and (c) a container.
4. The article of claim 3 wherein the retinal disease is diabetic
retinopathy or retinitis pigmentosa.
5. The article of claim 3 wherein said package insert reports that
incidences of flushing are less than 2% of treated patients.
6. The article of claims 1 through 5 wherein the oral dosage form
comprises about 5 mg, about 10 mg, or about 20 mg, of a selective
PDE5 inhibitor.
7. The article of claims 1 through 5 wherein the package insert
provides a maximum dosage of the selective PDE5 inhibitor of about
20 mg per 24-hour period.
8. The article of claims 1 through 5, wherein the selective PDE5
inhibitor has the structure 15
9. A method of treating sexual dysfunction comprising using an
article of manufacture of claims 1 through 5.
10. A method of treating sexual dysfunction in a patient being
treated with an organic nitrate comprising administration of an
oral dosage form of a PDE5 inhibitor in an amount of about 1 to
about 20 mg.
11. A method of treating sexual dysfunction in a patient prone to
vision abnormalities, prone to flushing, suffering from a retinal
disease, suffering from class 1 congestive heart failure, or that
suffered a myocardial infarction 90 days or more prior to onset of
the sexual dysfunction treatment comprising administration of an
oral dosage form of a PDE5 inhibitor in an amount of about 1 to
about 20 mg.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional patent
application Serial No. 60/132,036, filed Apr. 30, 1999.
FIELD OF THE INVENTION
[0002] The present invention relates to highly selective
phosphodiesterase (PDE) enzyme inhibitors and to their use in
pharmaceutical articles of manufacture. In particular, the present
invention relates to potent inhibitors of cyclic guanosine
3',5'-monophosphate specific phosphodiesterase type 5 (PDE5) that
when incorporated into a pharmaceutical product are useful for the
treatment of sexual dysfunction. The articles of manufacture
described herein are characterized by selective PDE5 inhibition,
and accordingly, provide a benefit in therapeutic areas where
inhibition of PDE5 is desired, with minimization or elimination of
adverse side effects resulting from inhibition of other
phosphodiesterase enzymes.
BACKGROUND OF THE INVENTION
[0003] The biochemical, physiological, and clinical effects of
cyclic guanosine 3',5'-monophosphate specific phosphodiesterase
(cGMP-specific PDE) inhibitors suggest their utility in a variety
of disease states in which modulation of smooth muscle, renal,
hemostatic, inflammatory, and/or endocrine function is desired.
Type 5 cGMP-specific phosphodiesterase (PDE5) is the major CGMP
hydrolyzing enzyme in vascular smooth muscle, and its expression in
penile corpus cavernosum has been reported (Taher et al., J. Urol.,
149:285A (1993)). Thus, PDE5 is an attractive target in the
treatment of sexual dysfunction (Murray, DN&P 6(3):150-56
(1993)).
[0004] A pharmaceutical product, which provides a PDE5 inhibitor,
is currently available and marketed under the trademark
VIAGRA.RTM.. The active ingredient in VIAGRA.RTM. is sildenafil.
The product is sold as an article of manufacture including 25, 50,
and 100 mg tablets of sildenafil and a package insert. The package
insert provides that sildenafil is a more potent inhibitor of PDE5
than other known phosphodiesterases (greater than 80 fold for PDE1
inhibition, greater than 1,000 fold for PDE2, PDE3, and PDE4
inhibition). The IC.sub.50 for sildenafil against PDE5 has been
reported as 3 nM (Drugs of the Future, 22(2), pp. 128-143 (1997)),
and as 3.9 nM (Boolell et al., Int. J. of Impotence Res., 8 p.
47-52 (1996)) Sildenafil is described as having a 4,000-fold
selectivity for PDE5 versus PDE3, and only a 10-fold selectivity
for PDE5 versus PDE6. Its relative lack of selectivity for PDE6 is
theorized to be the basis for abnormalities related to color
vision.
[0005] While sildenafil has obtained significant commercial
success, it has fallen short due to its significant adverse side
effects, including facial flushing (10% incidence rate). Adverse
side effects limit the use of sildenafil in patients suffering from
visual abnormalities, hypertension, and, most significantly, by
individuals who use organic nitrates (Welds et al., Amer. J. of
Cardiology, 83 (5A), pp. 21(C) -28(C) (1999)).
[0006] The use of sildenafil in patients taking organic nitrates is
believed to cause a clinically significant drop in blood pressure
which could place the patient in danger. Accordingly, the package
label for sildenafil provides strict contraindications against its
use in combination with organic nitrates (e.g., nitroglycerin,
isosorbide mononitrate, isosorbide dinitrate, erythrityl
tetranitrate) and other nitric oxide donors in any form, either
regularly or intermittently, because sildenafil potentiates the
hypotensive effects of nitrates. See C. R. Conti et al., Amer. J.
of Cardiology, 83(5A), pp. 29C-34C (1999). Thus, even with the
availability of sildenafil, there remains a need to identify
improved pharmaceutical products that are useful in treating sexual
dysfunction.
[0007] The present invention provides an article of manufacture for
human pharmaceutical use, comprising a package insert, a container,
and an oral dosage form comprising a selective PDE5 inhibitor at
unit dosages between about 1 and about 20 mg/dosage form. The
beneficial effects of the present invention were observed in
clinical studies and through the discovery that a selective PDE5
inhibitor meeting the following criteria allows for the effective
oral administration of about 1 to about 20 mg/dosage form without
contraindications generally required for PDE5 inhibitor products,
such as warnings directed to vision abnormalities. A selective PDE5
inhibitor of the present invention exhibits:
[0008] 1) at least a 100 fold differential in the IC.sub.50 values
for the inhibition of PDE5 versus PDE6 for a particular PDE5
inhibitor (i.e., the IC.sub.50 value versus PDE5 is at least 100
times less than the IC.sub.50 value versus PDE6);
[0009] 2) at least a 1000 fold differential in the IC.sub.50 values
for the inhibition of PDE5 versus PDE1c; and
[0010] 3) an IC.sub.50 value less than 10 nM.
[0011] Significantly, clinical studies also revealed that an
effective product having a reduced tendency to cause flushing in
susceptible individuals can be provided. Most unexpectedly, the
product also can be administered with clinically insignificant side
effects associated with the combined effects of a PDE5 inhibitor
and an organic nitrate. Thus, the contraindication once believed
necessary for a product containing a PDE5 inhibitor is unnecessary
when a selective PDE5 inhibitor, as defined above, is used as
disclosed herein. Thus, the present invention provides an effective
therapy for sexual dysfunction in individuals who previously were
untreatable or suffered from unacceptable side effects, including
individuals having cardiovascular disease, such as in individuals
requiring nitrate therapy, having suffered a myocardial infarction
more than three months before the onset of sexual dysfunction
therapy, and suffering from class 1 congestive heart failure as
defined by the New York Heart Association (NYHA), or individuals
suffering from vision abnormalities.
SUMMARY OF THE INVENTION
[0012] The present invention provides an article of manufacture for
human pharmaceutical use, comprising a package insert, a container,
and an oral dosage form comprising about 1 to about 20 mg of a
selective PDE5 inhibitor per dosage form.
[0013] The present invention further provides a method of treating
conditions where inhibition of PDE5 is desired, which comprises
administering to a patient in need thereof an oral dosage form
containing about 1 to about 20 mg of a selective PDE5 inhibitor, as
needed, up to a total dose of 20 mg/day. The invention further
provides the use of an oral dosage form comprising a selective PDE5
inhibitor at a dosage of about 1 to about 20 mg for the treatment
of sexual dysfunction.
[0014] Specific conditions that can be treated by the method and
article of the present invention, include, but are not limited to,
male erectile dysfunction and female sexual dysfunction,
particularly female arousal disorder, also known as female sexual
arousal disorder.
[0015] In particular, the present invention provides an article of
manufacture for human pharmaceutical use comprising:
[0016] (a) an oral dosage form comprising about 1 to about 20 mg of
a selective PDE5 inhibitor having
[0017] (i) at least a 100 fold differential in IC.sub.50 values for
the inhibition of PDE5 versus PDE6,
[0018] (ii) at least a 1000 fold differential in IC.sub.50 values
for the inhibition of PDE5 versus PDE1c,
[0019] (iii) an IC.sub.50 less than 10 nM, and
[0020] (iv) sufficient bioavailability to be effective in about 1
to about 20 mg unit oral dosages;
[0021] (b) a package insert providing that the PDE5 inhibitor is
useful to treat sexual dysfunction in a patient in need thereof,
and that is free of contradictions associated with administration
of organic nitrates; and
[0022] (c) a container.
[0023] The present invention further provides an article of
manufacture for human pharmaceutical use comprising:
[0024] (a) an oral dosage form comprising about 1 to about 20 mg of
selective PDE5 inhibitor having
[0025] (i) at least a 100 fold differential in IC.sub.50 values for
the inhibition of PDE5 versus PDE6,
[0026] (ii) at least a 1000 fold differential in IC.sub.50 values
for the inhibition of PDE5 versus PDE1c,
[0027] (iii) an IC.sub.50 less than 10 nM, and
[0028] (iv) a sufficient bioavailability to be effective in about 1
to about 20 mg unit oral dosages;
[0029] (b) a package insert providing that the PDE5 inhibitor is
useful to treat sexual dysfunction in a patient in need thereof and
that is using an organic nitrate; and
[0030] (c) a container.
[0031] The present invention also provides an article of
manufacture for human pharmaceutical use comprising:
[0032] (a) an oral dosage form comprising about 1 to about 20 mg of
a selective PDE5 inhibitor having
[0033] (i) at least a 100 fold differential in IC.sub.50 values for
the inhibition of PDE5 versus PDE6,
[0034] (ii) at least 1000 fold differential in IC.sub.50 values for
the inhibition of PDE5 versus PDE1c,
[0035] (iii) an IC.sub.50 less than 10 nM, and
[0036] (iv) a sufficient bioavailability to be effective in about 1
to about 20 mg unit oral dosages;
[0037] (b) a package insert providing that the PDE5 inhibitor is
useful to treat sexual dysfunction in a patient in need thereof and
that is suffering from a condition selected from the group
consisting of a retinal disease, proneness to flushing, proneness
to vision abnormalities, class 1 congestive heart failure, a
myocardial infarction 90 days or more before onset of the sexual
dysfunction treatment, and combinations thereof; and
[0038] (c) a container.
DETAILED DESCRIPTION
[0039] For purposes of the present invention as disclosed and
described herein, the following terms and abbreviations are defined
as follows.
[0040] The term "container" means any receptacle and closure
therefor suitable for storing, shipping, dispensing, and/or
handling a pharmaceutical product.
[0041] The term "IC.sub.50" is the measure of potency of a compound
to inhibit a particular PDE enzyme (e.g., PDE1c, PDE5, or PDE6).
The IC.sub.50 is the concentration of a compound that results in
50% enzyme inhibition in a single dose-response experiment.
Determining the IC.sub.50 value for a compound is readily carried
out by a known in vitro methodology generally described in Y. Cheng
et al., Biochem. Pharmacol., 22, pp. 3099-3108 (1973).
[0042] The term "package insert" means information accompanying the
product that provides a description of how to administer the
product, along with the safety and efficacy data required to allow
the physician, pharmacist, and patient to make an informed decision
regarding use of the product. The package insert generally is
regarded as the "label" for a pharmaceutical product.
[0043] The term "oral dosage form" is used in a general sense to
reference pharmaceutical products administered orally. Oral dosage
forms are recognized by those skilled in the art to include such
forms as liquid formulations, tablets, capsules, and gelcaps.
[0044] The term "selective PDE5 inhibitor" is defined as a PDE5
inhibitor having:
[0045] 1) an IC.sub.50 value for the inhibition of PDE5 at least
100 times less than the IC.sub.50 value for the inhibition of
PDE6;
[0046] 2) an IC.sub.50 value for the inhibition of PDE5 at least
1,000 times less than the IC.sub.50 value for the inhibition of
PDE1c; and
[0047] 3) an IC.sub.50 value for the inhibition of PDE5 less than
10 nM.
[0048] Selective PDE5 inhibitors vary significantly in chemical
structure, and their use in the present invention is not dependent
on chemical structure, but rather on the selectivity and potency
parameters disclosed herein.
[0049] The term "vision abnormalities" means abnormal vision
characterized by blue-green vision believed to be caused by PDE6
inhibition.
[0050] The term "flushing" means an episodic redness of the face
and neck attributed to vasodilation caused by the ingestion of a
drug, usually accompanied by a feeling of warmth over the face and
neck and sometimes accompanied by perspiration.
[0051] The term "free drug" means solid particles of drug not
intimately embedded in a polymeric coprecipitate.
[0052] As previously stated, the present invention is directed to
an article of manufacture for human pharmaceutical use, comprising
a package insert, a container, and a dosage form comprising about 1
to about 20 mg of a selective PDE5 inhibitor per unit dosage form.
A selective PDE5 inhibitor useful in the present invention is a
PDE5 inhibitor having:
[0053] 1) at least a 100 fold differential in IC.sub.5. values for
the inhibition of PDE5 versus PDE6;
[0054] 2) at least a 1000 fold differential in IC.sub.50 values for
the inhibition of PDE5 versus PDE1c; and
[0055] 3) an IC.sub.50 value less than 10 nM; and is sufficiently
bioavailable to be effective in about 1 to about 20 mg unit
dosages.
[0056] The differential is expressed as a PDE6/PDE5 ratio of
IC.sub.50 values, i.e., the ratio of the IC.sub.50 value versus
PDE6 to the IC.sub.50 value versus PDE5 (PDE6/PDE5) is greater than
100, more preferably greater than 300, and most preferably greater
than 500.
[0057] Similarly, the ratio of IC.sub.50 value versus PDE1c to
IC.sub.50 value versus PDE5 (PDE1c/PDE5) is greater than 1000.
Preferred PDE5 inhibitors have a greater than 3,000 fold
differential between the inhibition of PDE5 and PDE1c, more
preferably greater than a 5,000 fold differential between IC.sub.50
value versus PDE5 and PDE1c. The potency of the inhibitor, as
represented by the IC.sub.50 value versus PDE5, is less than 10 nM,
preferably less than 5 nM, more preferably less than 2 nM, and most
preferably less than 1 nM.
[0058] The package insert provides a description of how to
administer a pharmaceutical product, along with the safety and
efficacy data required to allow the physician, pharmacist, and
patient to make an informed decision regarding the use of the
product. The package insert generally is regarded as the label of
the pharmaceutical product. The package insert incorporated into
the present article of manufacture indicates that the selective
PDE5 inhibitor is useful in the treatment of conditions wherein
inhibition of PDE5 is desired. The package insert also provides
instructions to administer one or more about 1 to about 20 mg unit
dosage forms as needed, up to a maximum total dose of 20 mg per
day. Preferably, the dose administered is about 5 to about 20
mg/day, more preferably about 5 to about 15 mg, and most preferably
an about 5 mg or about 10 mg dosage form administered once per day,
as needed.
[0059] Preferred conditions to be treated include sexual
dysfunction (including male erectile dysfunction; and female sexual
dysfunction, and more preferably female arousal disorder (FAD)).
The preferred condition to be treated is male erectile
dysfunction.
[0060] Significantly, the package insert supports use of the
product to treat sexual dysfunction in patients suffering from a
retinal disease, for example diabetic retinopathy or retinitis
pigmentosa, or in patients who are using organic nitrates. Thus,
the package insert preferably is free of contraindications
associated with these conditions, and particularly the
administration of the dosage form with an organic nitrate. More
preferably, the package insert also is free of any cautions or
warnings both associated with retinal diseases, particularly
retinitis pigmentosa, and associated with individuals prone to
vision abnormalities. Preferably, the package insert also reports
incidences of flushing below 2%, preferably below 1%, and most
preferably below 0.5%, of the patients administered the dosage
form. The incidence rate of flushing demonstrates marked
improvement over prior pharmaceutical products containing a PDE5
inhibitor.
[0061] The container used in the present article of manufacture is
conventional in the pharmaceutical arts. Generally, the container
is a blister pack, foil packet, glass or plastic bottle and
accompanying cap or closure, or other such article suitable for use
by the patient or pharmacist. Preferably, the container is sized to
accommodate 1-1000 solid dosage forms, preferably 1 to 500 solid
dosage forms, and most preferably, 5 to 30 solid dosage forms.
[0062] Oral dosage forms are recognized by those skilled in the art
to include, for example, such forms as liquid formulations,
tablets, capsules, and gelcaps. Preferably the dosage forms are
solid dosage forms, particularly, tablets comprising about 1 to
about 20 mg of a selective PDE5 inhibitor. Any pharmaceutically
acceptable excipients for oral use are suitable for preparation of
such dosage forms. Suitable pharmaceutical dosage forms include
coprecipitate forms described, for example, in Butler U.S. Pat. No.
5,985,326, incorporated herein by reference. In preferred
embodiments, the unit dosage form of the present invention is a
solid free of a coprecipitate form of the PDE5 inhibitor, but
rather contains a solid PDE5 inhibitor as a free drug.
[0063] Preferably, the tablets comprise pharmaceutical excipients
generally recognized as safe such as lactose, microcrystalline
cellulose, starch, calcium carbonate, magnesium stearate, stearic
acid, talc, and colloidal silicon dioxide, and are prepared by
standard pharmaceutical manufacturing techniques as described in
Remington's Pharmaceutical Sciences, 18th Ed., Mack Publishing Co.,
Easton, Pa. (1990). Such techniques include, for example, wet
granulation followed by drying, milling, and compression into
tablets with or without film coating; dry granulation followed by
milling, compression into tablets with or without film coating; dry
blending followed by compression into tablets, with or without film
coating; molded tablets; wet granulation, dried and filled into
gelatin capsules; dry blend filled into gelatin capsules; or
suspension and solution filled into gelatin capsules. Generally,
the solid dosage forms have identifying marks which are debossed or
imprinted on the surface.
[0064] The present invention is based on detailed experiments and
clinical trials, and the unexpected observations that side effects
previously believed to be indicative of PDE5 inhibition can be
reduced to clinically insignificant levels by the selection of a
selective PDE5 inhibitor having the specific characteristics
outlined herein, namely:
[0065] 1) at least a 100 fold differential in the IC.sub.50 values
for the inhibition of PDE5 versus PDE6;
[0066] 2) at least a 1000 fold differential in the IC.sub.50 values
for the inhibition of PDE5 versus PDE1c; and
[0067] 3) an IC.sub.50 value for the inhibition of PDE5 less than
10 nM.
[0068] This unexpected observation enabled the development of
articles of manufacture that incorporate a selective PDE5 inhibitor
in about 1 to about 20 mg unit dosage forms that, when orally
administered, minimize undesired side effects previously believed
unavoidable. These side effects include facial flushing, vision
abnormalities, and a significant decrease in blood pressure when
the PDE5 inhibitor is administered alone or in combination with an
organic nitrate. The minimal effect of a present PDE5 inhibitor,
administered in about 1 to about 20 mg unit dosage forms, on PDE6
also allows the administration of a selective PDE5 inhibitor to
patients suffering from a retinal disease, like diabetic
retinopathy or retinitis pigmentosa.
[0069] One such selective PDE5 inhibitor, i.e.,
(6R-trans)-6-(1,3-benzodio-
xol-5-yl)-2,3,6,7,12,12a-hexahydro-2-methylpyrazino[1',2':1,6]pyrido[3,4-b-
]indole-1,4-dione, alternatively named
(6R,12aR)-2,3,6,7,12,12a-hexahydro--
2-methyl-6-(3,4-methylenedioxyphenyl)pyrazino[2',1':6,1]pyrido[3,4-b]indol-
e-1,4-dione, is disclosed in Daugan U.S. Pat. No. 5,859,006, and
represented by structural formula (I): 1
[0070] The compound of formula (I) was demonstrated in human
clinical studies to exert a minimal impact on systolic blood
pressure when administered in conjunction with organic nitrates. By
contrast, sildenafil, when administered with nitrates, demonstrates
as much as a four-fold greater decrease in systolic blood pressure
over a placebo, which leads to the contraindications in the
VIAGRA.RTM. insert, and in warnings to certain patients.
[0071] Selective PDE5 inhibitors vary significantly in chemical
structure, and the use of a selective PDE5 inhibitor as defined in
the present invention is not dependent on a particular chemical
structure, but rather on the critical parameters outlined herein.
However, preferred compounds having the required potency and
selectivity can be readily identified by tests described herein
from those described in Daugan U.S. Pat. No. 5,859,006, Daugan et
al. U.S. Pat. No. 5,981,527, and Daugan et al. U.S. Pat. No.
6,001,847, each of which is incorporated herein by reference.
[0072] Preferred compounds of Daugan U.S. Pat. No. 5,859,006 and
Daugan et al. U.S. Pat. No. 5,981,527 are represented by structural
formula (II): 2
[0073] wherein
[0074] R.sup.0 is selected from the group consisting of hydrogen,
halogen, and C.sub.1-6alkyl;
[0075] R.sup.1 is selected from the group consisting of hydrogen,
C.sub.1-6alkyl, C.sub.2-6alkenyl, C.sub.2-6alkynyl,
halo-C.sub.1-6alkyl, C.sub.3-8cycloalkyl,
C.sub.3-8cycloalkylC.sub.1-3alkyl, arylC.sub.1-3alkyl, wherein aryl
is phenyl or phenyl substituted with one to three substituents
selected from the group consisting of halogen, C.sub.1-6alkyl,
C.sub.1-6alkoxy, methylenedioxy, and mixtures thereof, and
heteroarylC.sub.1-3alkyl, wherein heteroaryl is thienyl, furyl, or
pyridyl, each optionally substituted with one to three substituents
selected from the group consisting of halogen, C.sub.1-6alkyl,
C.sub.1-6alkoxy, and mixtures thereof;
[0076] R.sup.2 represents an optionally substituted monocyclic
aromatic ring selected from benzene, thiophene, furan, and
pyridine, or an optionally substituted bicyclic ring 3
[0077] attached to the rest of the molecule via one of the benzene
ring carbon atoms and wherein the fused ring A is a 5- or
6-membered ring, saturated or partially or fully unsaturated, and
comprises carbon atoms and optionally one or two heteroatoms
selected from the group consisting of oxygen, sulphur and
nitrogen;
[0078] R.sup.3 represents hydrogen or C.sub.1-3alkyl, or R.sup.1
and R.sup.3 together represent a 3- or 4-membered alkyl or alkenyl
chain; and salts and solvates thereof.
[0079] Other preferred compounds are those of formula (II)
wherein:
[0080] R.sup.0 is hydrogen, halogen, or C.sub.1-6alkyl;
[0081] R.sup.1 is hydrogen or C.sub.1-6alkyl;
[0082] R.sup.2 is the bicyclic ring 4
[0083] which can be optionally substituted by one or more groups
selected from halogen and C.sub.1-3alkyl; and
[0084] R.sup.3 is hydrogen or C.sub.1-3alkyl.
[0085] The following Table 1 illustrates PDE5 and PDE6 IC.sub.50
values for representative selective PDE5 inhibitors disclosed in
U.S. Pat. No. 5,859,006, as determined by the procedures described
herein.
1TABLE 1 Compound PDE5 IC.sub.50 (nM) PDE6 IC.sub.50 (nM) PDE6/PDE5
1 5 663 133 2 2 937 469 3 2 420 210 4 5 729 146 5 2.5 3400 1360
[0086] Compound 5 in Table 1 has the structural formula (I) and
additionally demonstrates an IC.sub.5o against PDE1c of 10,000 and
a ratio of PDE1c/PDE5 of 4,000.
[0087] The structures of Compound Nos. 1-5 in Table 1 are as in
structural formula (II) wherein R.sup.0, R.sup.1, R.sup.2, and
R.sup.3 are as follows:
2 Compound R.sup.0 R.sup.1 R.sup.2 R.sup.3 1 H 5 6 H 2 H CH.sub.3 7
H 3 H 8 9 H 4 H H 10 CH.sub.3 5 H CH.sub.3 11 H
[0088] The data in Table 1 indicate that a compound of structural
formula (I), wherein R.sup.1 is hydrogen or C.sub.1-6alkyl, R.sup.2
is 12
[0089] and R.sup.3 is hydrogen is especially preferred. Preferably,
A is 13
[0090] Preferred compounds are:
(6R,12aR)-2,3,6,7,12,12a-hexahydro-2-methy-
l-6-(3,4-methylenedioxyphenyl)pyrazino[2',1':6,1]pyrido[3,4-b]indole-1,4-d-
ione; and
(3s,6R,12aR)-2,3,6,7,12,12a-hexahydro-2,3-dimethyl-6-(3,4-methyl-
enedioxyphenyl)pyrazino[2',1':6,1]-pyrido[3,4-b]indole-1,4-dione;
and physiologically acceptable salts and solvates (e.g., hydrates)
thereof.
[0091] Other exemplary compounds useful in the present invention
are those disclosed in Daugan et al. U.S. Pat. No. 6,001,847 and WO
97/43287, incorporated herein by reference.
[0092] Further exemplary compounds for use in the present invention
are disclosed PCT application PCT/EP98/06050, which designates the
U.S., entitled "Chemical Compounds," inventors A. Bombrun and F.
Gellibert, the disclosure of which is specifically incorporated
herein by reference. This class of compounds has the structural
formula (III): 14
[0093] and salts and solvates (e.g., hydrates) wherein
[0094] C represents a 5- or 6-membered heteroaryl group containing
at least one heteroatom selected from the group consisting of
oxygen, nitrogen, and sulfur;
[0095] R.sup.12 represents hydrogen or halogen;
[0096] R.sup.13 is selected from the group consisting of
[0097] hydrogen,
[0098] nitro (NO.sub.2),
[0099] trifluoromethyl,
[0100] trifluoromethoxy,
[0101] halogen,
[0102] cyano (CN),
[0103] a 5- or 6-membered heterocyclic group containing at least
one heteroatom selected from the group consisting of oxygen,
nitrogen, and sulphur, optionally substituted with
C(.dbd.O)OR.sup.a or C.sub.14alkyl,
[0104] C.sub.16alkyl optionally substituted with OR.sup.h,
[0105] C.sub.1-3alkoxy,
[0106] C(.dbd.O)R.sup.h,
[0107] OC(.dbd.O)OR.sup.h,
[0108] C(=O)OR.sup.h,
[0109] C.sub.1-4alkyleneHet,
[0110] C.sub.14alkyleneC(.dbd.O)OR.sup.h,
[0111] OC.sub.1-4alkyleneC(.dbd.O)OR.sup.h,
[0112] C.sub.1-4alkyleneOC.sub.1-4alkyleneC(.dbd.O) OR.sup.h,
[0113] C(.dbd.O)NR.sup.iSO.sub.2R.sup.j,
[0114] C(.dbd.O)C.sub.1-4alkyleneHet,
[0115] C.sub.1-4alkyleneNR.sup.hR.sup.i,
[0116] C.sub.2-6alkenyleneNR.sup.hR.sup.i,
[0117] C(.dbd.O)NR.sup.hR.sup.i,
[0118] C(.dbd.O)NR.sup.hR.sup.i,
[0119] C(.dbd.O)NR.sup.hC.sub.1-4alkyleneOR.sup.i,
[0120] C(.dbd.O)NR.sup.hC.sub.1-4alkyleneHet,
[0121] OR.sup.i,
[0122] OC.sub.2-4alkyleneNR.sup.hR.sup.i,
[0123] OC.sub.1-4alkyleneCH(OR.sup.h)CH.sub.2NR.sup.hR.sup.i,
[0124] OC.sub.1-4alkyleneHet,
[0125] OC.sub.2-4alkyleneOR.sup.h,
[0126] OC.sub.2-4alkyleneNR.sup.hC(.dbd.O) OR.sup.h,
[0127] NR.sup.hR.sup.i,
[0128] NR.sup.hC.sub.1-4alkyleneNR.sup.hR.sup.i,
[0129] NR.sup.hC(.dbd.O)R.sup.i,
[0130] NR.sup.hC(.dbd.O)NR.sup.hR.sup.i,
[0131] N(SO.sub.2C.sub.1-4alkyl).sub.2,
[0132] NR.sup.h(SO.sub.2C.sub.1-4alkyl),
[0133] SO.sub.2NR.sup.hR.sup.i,
[0134] and OSO.sub.2trifluoromethyl;
[0135] R.sup.14 is selected from the group consisting of hydrogen,
halogen, OR.sup.h, C.sub.1-6alkyl, NO.sub.2, and
NR.sup.hR.sup.i;
[0136] or R.sup.13 and R.sup.14 are taken together to form a 3- or
4-membered alkylene or alkenylene chain component of a 5- or
6-membered ring, optionally containing at least one heteroatom;
[0137] R.sup.15 is selected from the group consisting of hydrogen,
halogen, NO.sub.2, trifluoromethoxy, C.sub.1-6alkyl,
OC.sub.1-6alkyl, and C(.dbd.O)OR.sup.h;
[0138] R.sup.16 is hydrogen,
[0139] or R.sup.15 and R.sup.16 are taken together to form a 3- or
4-membered alkylene or alkenylene chain component of a 5- or
6-membered ring, optionally containing at least one heteroatom;
[0140] Het represents a 5- or 6-membered heterocyclic group
containing at least one heteroatom selected from the group
consisting of oxygen, nitrogen, and sulfur, and optionally
substituted with C.sub.1-4alkyl;
[0141] R.sup.h and R.sup.i can be the same or different and are
independently selected from hydrogen and C.sub.1-6alkyl;
[0142] R.sup.j represents phenyl or C.sub.4-6cycloalkyl, wherein
the phenyl or C.sub.4-6cycloalkyl can be optionally substituted
with one or more halogen atoms, one or more C(.dbd.O)OR.sup.h, or
one or more OR.sup.h;
[0143] n is an integer 1, 2, or 3; and
[0144] m is an integer 1 or 2.
[0145] Preparations
[0146] Human PDE5 Preparation
[0147] Recombinant production of human PDE5 was carried out
essentially as described in Example 7 of U.S. Pat. No. 5,702,936,
incorporated herein by reference, except that the yeast
transformation vector employed, which is derived from the basic
ADH2 plasmid described in V. Price et al., Methods in Enzymology,
1985, pages 308-318 (1990), incorporated yeast ADH2 promoter and
terminator sequences rather than ADH1 promoter and terminator
sequences and the Saccharomyces cerevisiase host was the
protease-deficient strain BJ2-54 deposited on Aug. 31, 1998 with
the American Type Culture Collection, Manassas, Va., under
accession number ATCC 74465. Transformed host cells were grown in
2.times. SC-leu medium, pH 6.2, with trace metals, and vitamins.
After 24 hours, YEP medium containing glycerol was added to a final
concentration of 2.times. YEP/3% glycerol. Approximately 24 hours
later, cells were harvested, washed, and stored at -70.degree.
C.
[0148] Cell pellets (29 g) were thawed on ice with an equal volume
of lysis buffer (25 mM Tris-Cl, pH 8, 5 mM MgCl.sub.2, 0.25 mM
dithiothreitol, 1 mM benzamidine, and 10 .mu.M ZnSO.sub.4). Cells
were lysed in a microfluidizer with N.sub.2 at 20,000 psi. The
lysate was centrifuged and filtered through 0.45 .mu.m disposable
filters. The filtrate was applied to a 150 mL column of Q Sepharose
Fast Flow (Pharmacia). The column was washed with 1.5 volumes of
Buffer A (20 mM Bis-Tris Propane, pH 6.8, 1 mM MgCl.sub.2, 0.25 mM
dithiothreitol, 10 .mu.M ZnSO.sub.4) and eluted with a step
gradient of 125 mM NaCl in Buffer A followed by a linear gradient
of 125-1000 mM NaCl in Buffer A.
[0149] Active fractions from the linear gradient were applied to a
180 mL hydroxyapatite column in Buffer B (20 mM Bis-Tris Propane
(pH 6.8), 1 mM MgCl.sub.2, 0.25 mM dithiothreitol, 10 .mu.M
ZnSO.sub.4, and 250 mM KCl). After loading, the column was washed
with 2 volumes of Buffer B and eluted with a linear gradient of
0-125 mM potassium phosphate in Buffer B. Active fractions were
pooled, precipitated with 60% ammonium sulfate, and resuspended in
Buffer C (20 mM Bis-Tris Propane, pH 6.8, 125 mM NaCl, 0.5 mM
dithiothreitol, and 10 .mu.M ZnSO.sub.4). The pool was applied to a
140 mL column of Sephacryl S-300HR and eluted with Buffer C. Active
fractions were diluted to 50% glycerol and stored at -20.degree. C.
The resultant preparations were about 85% pure by SDS-PAGE.
[0150] Assay for PDE Activity
[0151] Activity of PDE5 can be measured by standard assays in the
art. For example, specific activity of any PDE can be determined as
follows. PDE assays utilizing a charcoal separation technique were
performed essentially as described in Loughney et al., (1996), The
Journal of Biological Chemistry, 271:796-806. In this assay, PDE5
activity converts [.sup.32P]cGMP to [.sup.32P]5'GMP in proportion
to the amount of PDE5 activity present. The [.sup.32P] 5'GMP then
is quantitatively converted to free [.sup.32P] phosphate and
unlabeled adenosine by the action of snake venom 5'-nucleotidase.
Hence, the amount of [.sup.32P] phosphate liberated is proportional
to enzyme activity. The assay is performed at 30 C in a 100 .mu.L
reaction mixture containing (final concentrations) 40 mM Tris-Cl
(pH 8.0), 1 .mu.M ZnSO.sub.4, 5 mM MgCl.sub.2, and 0.1 mg/mL bovine
serium albumin. PDE5 is present in quantities that yield <30%
total hydrolysis of substrate (linear assay conditions). The assay
is initiated by addition of substrate (1 mM [.sup.32P]cGMP), and
the mixture is incubated for 12 minutes. Seventy-five (75) .mu.g of
Crotalus atrox venom then is added, and the incubation is continued
for 3 more minutes (15 minutes total). The reaction is stopped by
addition of 200 mL of activated charcoal (25 mg/mL suspension in
0.1 M NaH.sub.2PO.sub.4, pH 4). After centrifugation (750.times. g
for 3 minutes) to sediment the charcoal, a sample of the
supernatant is taken for radioactivity determination in a
scintillation counter and the PDE5 activity is calculated. The
preparations had specific activities of about 3 .mu.moles cGMP
hydrolyzed per minute per milligram protein.
[0152] Bovine PDE6 Preparation
[0153] Bovine PDE6 was supplied by Dr. N. Virmaux, INSERM U338,
Strasbourg. Bovine retinas were prepared as described by Virmaux et
al., FEBS Letters, 12(6), pp. 325-328 (1971) and see also, A.
Sitaramayya et al., Exp. Eye Res., 25, pp. 163-169 (1977). Briefly,
unless stated otherwise, all operations were done in the cold and
in dim red light. Eyes were kept in the cold and in the dark for up
to four hours after slaughtering.
[0154] Preparation of bovine retinal outer segment (ROS) basically
followed procedures described by Schichi et al., J. Biol. Chem.,
224:529 (1969). In a typical experiment, 35 bovine retinas were
ground in a mortar with 35 mL 0.066 M phosphate buffer, pH 7.0,
made up to 40% with sucrose, followed by homogenization in a Potter
homogenizer (20 up and down strokes). The suspension was
centrifuged at 25,000.times. g for 20 minutes. The pellet was
homogenized in 7.5 mL 0.006 M phosphate buffer (40% in sucrose),
and carefully layered under 7.5 mL of phosphate buffer (containing
no sucrose). Centrifugation was conducted in a swing-out rotor at
45,000.times. g for 20 minutes, and produced a pellet which is
black at the bottom, and also a red band at the interface 0.066 M.
phosphate--40% sucrose/0.066 M phosphate (crude ROS). The red
material at the interface was removed, diluted with phosphate
buffer, spun down to a pellet, and redistributed in buffered 40%
sucrose as described above. This procedure was repeated 2 or 3
times until no pellet was formed. The purified ROS was washed in
phosphate buffer and finally spun down to a pellet at 25,000.times.
g for 20 minutes. All materials were then kept frozen until
used.
[0155] Hypotonic extracts were prepared by suspending isolated ROS
in 10 mM Tris-Cl pH 7.5, 1 mM EDTA, and 1 mM dithioerythritol,
followed by centrifugation at 100,000.times. g for 30 minutes.
[0156] The preparation was reported to have a specific activity of
about 35 nmoles cGMP hydrolyzed per minute per milligram
protein.
[0157] PDE1c Preparation from Spodoptera fugiperda Cells (Sf9)
[0158] Cell pellets (59) were thawed on ice with 20 ml of Lysis
Buffer (50 mM MOPS pH 7.4, 10 .mu.M ZnSO.sub.4, 0.1 mM CaCl.sub.2,
1 mM DTT, 2 mM benzamidine HCl, 5 .mu.g/ml each of pepstatin,
leupeptin, and aprotenin). Cells were lysed by passage through a
French pressure cell (SLM-Aminco) while temperatures were
maintained below 10.degree. C. The resultant cell homogenate was
centrifuged at 36,000 rpm at 4.degree. C. for 45 minutes in a
Beckman ultracentrifuge using a Type TI45 rotor. The supernatant
was discarded and the resultant pellet was resuspended with 40 ml
of Solubilization Buffer (Lysis Buffer containing 1M NaCl, 0.1M
MgCl.sub.2, 1 mM CaCl.sub.2, 20 ug/ml calmodulin, and 1%
Sulfobetaine SB12 (Z3-12) by sonicating using a VibraCell tuner
with a microtip for 3.times.30 seconds. This was performed in a
crushed ice/salt mix for cooling. Following sonication, the mixture
was slowly mixed for 30 minutes at 4.degree. C. to finish
solubilizing membrane bound proteins. This mixture was centrifuged
in a Beckman ultracentrifuge using a type TI45 rotor at 36,000 rpm
for 45 minutes. The supernatant was diluted with Lysis Buffer
containing 10 .mu.g/ml calpain inhibitor I and II. The precipitated
protein was centrifuged for 20 minutes at 9,000 rpm in a Beckman
JA-10 rotor. The recovered supernatant then was subjected to
Mimetic Blue AP Agarose Chromatography.
[0159] In order to run the Mimetic Blue AP Agarose Column, the
resin initially was shielded by the application of 10 bed volumes
of 1% polyvinyl-pyrrolidine (i.e., MW of 40,000) to block
nonspecific binding sites. The loosely bound PVP-40 was removed by
washing with 10 bed volumes of 2M NaCl, and 10 mM sodium citrate pH
3.4. Just prior to addition of the solubilized PDE1c sample, the
column was equilibrated with 5 bed volumes of Column Buffer A (50
mM MOPS pH 7.4, 10 .mu.M ZnSO.sub.4, 5 mM MgCl.sub.2, 0.1 mM
CaCl.sub.2, 1 mM DTT, 2 mM benzamidine HCl).
[0160] The solubilized sample was applied to the column at a flow
rate of 2 ml/min with recycling such that the total sample was
applied 4 to 5 times in 12 hours. After loading was completed, the
column was washed with 10 column volumes of Column Buffer A,
followed by 5 column volumes of Column Buffer B (Column Buffer A
containing 20 mM 5'-AMP), and followed by 5 column volumes of
Column Buffer C (50 mM MOPS pH 7.4, 10 uM ZnSO.sub.4, 0.1 mM
CaCl.sub.2, 1 mM dithiothreitol, and 2 mM benzamidine HCl). The
enzyme was eluted into three successive pools. The first pool
consisted of enzyme from a 5 bed volume wash with Column Buffer C
containing 1 mM cAMP. The second pool consisted of enzyme from a 10
bed volume wash with Column Buffer C containing 1 M NaCl. The final
pool of enzyme consisted of a 5 bed volume wash with Column Buffer
C containing 1 M NaCl and 20 mM cAMP.
[0161] The active pools of enzyme were collected and the cyclic
nucleotide removed via conventional gel filtration chromatography
or chromatography on hydroxy-apatite resins. Following removal of
cyclic nucleotides, the enzyme pools were dialyzed against Dialysis
Buffer containing 25 mM MOPS pH 7.4, 10 .mu.M ZnSO.sub.4, 500 mM
NaCl, 1 mM CaCl.sub.2, 1 mM dithiothreitol, 1 mM benzamidine HCl,
followed by dialysis against Dialysis buffer containing 50%
glycerol. The enzyme was quick frozen with the aid of dry ice and
stored at -70.degree. C.
[0162] The resultant preparations were about >90% pure by
SDS-PAGE. These preparations had specific activities of about 0.1
to 1.0 .mu.mol cAMP hydrolyzed per minute per milligram
protein.
[0163] IC.sub.50 Value Determinations
[0164] The parameter of interest in evaluating the potency of a
competitive enzyme inhibitor of PDE5 and/or PDE1c and PDE6 is the
inhibition constant, i.e., K.sub.i. This parameter can be
approximated by determining the IC.sub.50, which is the inhibitor
concentration that results in 50% enzyme inhibition, in a single
dose-response experiment under the following conditions.
[0165] The concentration of inhibitor is always much greater than
the concentration of enzyme, so that free inhibitor concentration
(which is unknown) is approximated by total inhibitor concentration
(which is known).
[0166] A suitable range of inhibitor concentrations is chosen
(i.e., inhibitor concentrations at least several fold greater and
several fold less than the K.sub.i are present in the experiment).
Typically, inhibitor concentrations ranged from 10 nM to 10
.mu.M.
[0167] The concentrations of enzyme and substrate are chosen such
that less than 20% of the substrate is consumed in the absence of
inhibitor (providing, e.g., maximum substrate hydrolysis of from 10
to 15%), so that enzyme activity is approximately constant
throughout the assay.
[0168] The concentration of substrate is less than one-tenth the
Michaelis constant (K.sub.m). Under these conditions, the IC.sub.50
will closely approximate the K.sub.i. This is because of the
Cheng-Prusoff equation relating these two parameters:
IC.sub.50=K.sub.i(1+S/K.sub.m), with (1+S/K.sub.m) approximately 1
at low values of S/K.sub.m.
[0169] The IC.sub.50 value is estimated from the data points by
fitting the data to a suitable model of the enzyme inhibitor
interaction. When this interaction is known to involve simple
competition of the inhibitor with the substrate, a two-parameter
model can be used:
Y=A/(1+x/B)
[0170] where the y is the enzyme activity measured at an inhibitor
concentration of x, A is the activity in the absence of inhibitor
and B is the IC.sub.50. See Y. Cheng et al., Biochem. Pharmacol.,
22:3099-3108 (1973).
[0171] Effects of inhibitors of the present invention on enzymatic
activity of PDE5 and PDE6 preparations as described above were
assessed in either of two assays which differed from each other
principally on the basis of scale and provided essentially the same
results in terms of IC.sub.50 values. Both assays involved
modification of the procedure of Wells et al., Biochim. Biophys.
Acta, 384:430 (1975). The first of the assays was performed in a
total volume of 200 .mu.l containing 50 mM Tris pH 7.5, 3 mM Mg
acetate, 1 mM EDTA, 50 .mu.g/mL snake venom nucleotidase and 50 nM
[.sup.3H]-cGMP (Amersham). Compounds of the invention were
dissolved in DMSO finally present at 2% in the assay. The assays
were incubated for 30 minutes at 30.degree. C. and stopped by
addition of 800 .mu.l of 10 mM Tris pH 7.5, 10 mM EDTA, 10 mM
theophylline, 0.1 mM adenosine, and 0.1 mM guanosine. The mixtures
were loaded on to 0.5 mL QAE Sephadex columns, and eluted with 2 mL
of 0.1 M formate (pH 7.4). The eluted radioactivity was measured by
scintillation counting in Optiphase Hisafe 3.
[0172] A second, microplate, PDE assay was developed using
Multiscreen plates and a vacuum manifold. The assay (100 .mu.l)
contained 50 mM Tris pH 7.5, 5 mM Mg acetate, 1 mM EDTA and 250
.mu.g/mL snake venom nucleotidase. The other components of the
reaction mixture were as described above. At the end of the
incubation, the total volume of the assays were loaded on a QAE
Sephadex microcolumn plate by filtration. Free radioactivity was
eluted with 200 .mu.l of water from which 50 .mu.l aliquots were
analyzed by scintillation counting as described above.
[0173] The following examples are presented to further illustrate
the preparation of the claimed invention. The scope of the present
invention is not to be construed as merely consisting of the
following examples.
EXAMPLE 1
[0174] The compound of structural formula (I) was prepared as
described in U.S. Pat. No. 5,859,006 and formulated in tablets
using wet granulation. Povidone was dissolved in water to make a
10% solution. The active compound, microcrystalline cellulose,
croscarmellose sodium, and sodium lauryl sulfate were added to a
high shear mixer and mixed for 2 minutes. The powders were wet
granulated with the povidone solution and extra water as required
to complete the granulation. The resultant mixture was dried in a
fluid bed drier with inlet air at 70.degree. C.+-.5.degree. C.
until the loss on drying was below 2.5%. The granules were passed
through a Comil with a suitable screen (or a sieve) and added to a
suitable mixer. The extragranular croscarmellose sodium and sodium
lauryl sulfate, and the colloidal anhydrous silica were passed
through a suitable sieve (e.g., 500 micron) and added to the mixer
and blended 5 minutes. Magnesium stearate was added and blended for
2 minutes. The blend was compressed to a target compression/weight
of 250 mg using 9 mm round normal concave tooling.
[0175] The core tablets were coated with an aqueous suspension of
Opadry OY-S-7322 using an Accelacota (or similar coating pan) using
inlet air at 50.degree. C. to 70.degree. C. until the tablet weight
was increased by approximately 8 mg. Opadry OY-S-7322 contains
methylhydroxypropylcellulos- e Ph.Eur., titanium dioxide Ph. Eur.,
Triacetin USP. Opadry increases the weight of each tablet to about
258 mg. The amount of film coat applied per tablet may be less than
that stated depending on the process efficiency.
[0176] The tablets are filled into blister packs and accompanied by
package insert describing the safety and efficacy of the
compound.
3 Formulations Component (mg per tablet) Selective PDE5
Inhibitor.sup.1) 1 5 Hydroxypropylmethylcellulose 1 5 phthalate
Microcrystalline Cellulose 221.87 213.87 Croscarmellose Sodium 5.00
5.00 Sodium Lauryl Sulfate 2.50 2.50 Sulfate Povidone K30 9.38 9.38
Purified Water, USP (water q.s. q.s. for irrigation) Croscarmellose
Sodium 5.00 5.00 Sodium Lauryl Sulfate 2.50 2.50 Colloidal
Anhydrous Silica 0.50 0.50 Magnesium Stearate 1.25 1.25 Total core
subtotal 250.00 250.00 (Film coat Opadry OY-S-7322) about 8 mg
about 8 mg .sup.1)Compound of structural formula (I).
EXAMPLE 2
[0177] The following formula is used in preparing a finished dosage
form containing 10 mg of the compound of structural formula
(I).
4 Ingredient Quantity (mg) Granulation Selective PDE5
Inhibitor.sup.1) 10.00 Lactose Monohydrate 153.80 Lactose
Monohydrate (spray dried) 25.00 Hydroxypropylcellulose 4.00
Croscarmellose Sodium 9.00 Hydroxypropylcellulose (EF) 1.75 Sodium
Lauryl Sulfate 0.70 35.00 Outside Powders Microcrystalline
Cellulose (granular-102) 37.50 Croscarmellose Sodium 7.00 Magnesium
Stearate (vegetable) 1.25 Total 250 mg Film coat (approximately)
11.25
[0178] Purified Water, USP is used in the manufacture of the
tablets. The water is removed during processing and minimal levels
remain in the finished product.
[0179] Tablets are manufactured using a wet granulation process. A
step-by-step description of the process is as follows. The drug and
excipients to be granulated are security sieved. The selective PDE5
inhibitor is dry blended with lactose monohydrate (spray dried),
hydroxypropylcellulose, croscarmellulose sodium, and lactose
monohydrate. The resulting powder blend is granulated with an
aqueous solution of hydroxypropylcellulose and sodium lauryl
sulfate using a Powrex or other suitable high shear granulator.
Additional water can be added to reach the desired endpoint. A mill
can be used to delump the wet granulation and facilitate drying.
The wet granulation is dried using either a fluid bed dryer or a
drying oven. Once the material is dried, it can be sized to
eliminate any large agglomerates. Microcrystalline cellulose,
croscarmellose sodium, and magnesium stearate are security sieved
and added to the dry sized granules. These excipients and the dry
granulation are mixed until uniform using a tumble bin, ribbon
mixer, or other suitable mixing equipment. The mixing process can
be separated into two phases. The microcrystalline cellulose,
croscarmellose sodium, and the dried granulation are added to the
mixer and blended during the first phase, followed by the addition
of the magnesium stearate to this granulation and a second mixing
phase.
[0180] The mixed granulation then is compressed into tablets using
a rotary compression machine. The core tablets are film coated with
an aqueous suspension of the appropriate color mixture in a coating
pan (e.g., Accela Cota). The coated tablets can be lightly dusted
with talc to improve tablet handling characteristics.
[0181] The tablets are filled into plastic containers (30
tablets/container) and accompanied by package insert describing the
safety and efficacy of the compound.
EXAMPLE 3
[0182] The following formula is used in preparing a finished dosage
form of 5 mg of the compound of structural formula (I).
5 Ingredient Quantity (mg) Granulation Selective PDE5
Inhibitor.sup.1) 2.50 Lactose Monohydrate 79.395 Lactose
Monohydrate (spray dried) 12.50 Hydroxypropylcellulose 2.00
Croscarmellose Sodium 4.50 Hydroxypropylcellulose (EF) 0.875 Sodium
Lauryl Sulfate 0.35 Outside Powders Microcrystalline Cellulose
(granular-102) 18.75 Croscarmellose Sodium 3.50 Magnesium Stearate
(vegetable) 0.63 Total 125 mg Film coat (approximately) 6.875
[0183] The dosage form of Example 3 was prepared in an identical
manner to the dosage form of Example 2.
EXAMPLE 4
[0184]
6 Solution Capsule Ingredient mg/capsule Percent (%) Selective PDE5
Inhibitor.sup.1) 10 2 PEG400 NF 490 98 Fill Weight 500 100
[0185] The gelatin capsules are precisely filled by pumping an
accurate fill volume of pre-dissolved drug formulation into the
partially sealed cavity of a capsule. Immediately following
injection fill of the drug solution formulation, the capsule is
completely heat sealed.
[0186] The capsules are filled into plastic containers and
accompanied by a package insert.
EXAMPLE 5
[0187] This study was a randomized, double-blind,
placebo-controlled, two-way crossover design clinical pharmacology
drug interaction study that evaluated the hemodynamic effects of
concomitant administration of a selective PDE5 inhibitor Study Drug
(i.e., the compound of structural formula (I)) and short-acting
nitrates on healthy male volunteers. In this study, the subjects
received either the Study Drug at a dose of 10 mg or a placebo,
daily for seven days. On the sixth or seventh day, the subjects
received sublingual nitroglycerin (0.4 mg) while supine on a tilt
table. The nitroglycerin was administered 3 hours after Study Drug
dosing, and all subjects kept the nitroglycerin tablet under their
tongue until it completely dissolved. The subjects were tilted to
700 head-up every 5 minutes for a total of 30 minutes with
measurement of blood pressure and heart rate. There were no
discontinuations among the twenty-two healthy male subjects (ages
19 to 60 years old) that entered this study.
[0188] In a preliminary analysis of this study, the Study Drug was
well tolerated and there were no serious adverse events. There were
no Study Drug-associated changes in laboratory safety assessments
or 12-lead ECGs. The most common adverse events were headache,
dyspepsia, and back pain. The study demonstrated minimal effects on
mean systolic blood pressure and on mean maximal
nitroglycerin-induced decrease in systolic blood pressure and the
maximal nitroglycerin-induced decrease in systolic blood pressure
among all patients.
EXAMPLE 6
[0189] In two randomized, double-blinded placebo controlled
studies, the compound of structural formula (I), at a range of
doses in both daily dosing and for on demand therapy for sexual
encounters and intercourse in the home setting, was administered to
patients in need thereof. Doses from 5 to 20 mg of the compound of
structural formula (I) were efficacious and demonstrated no
flushing and no reports of vision abnormalities. It was found that
a 10 mg dose of the compound of structural formula (I) was fully
efficacious and demonstrated minimal side effects (no flushing and
no reports of blue vision).
[0190] Erectile function was assessed by the International Index of
Erectile Function (IIEF) (Rosen et al., Urology, 49, pp. 822-830
(1997)), diaries of sexual attempts, and a global satisfaction
question. The compound of structural formula (I) significantly
improved erectile function as assessed by all endpoints. In both
"on demand" and daily dose regimens, the compound of structural
formula (I) significantly improved erectile function in doses
between 1 and 20 mg.
EXAMPLE 7
[0191] A third clinical study was a randomized, double-blind,
placebo-controlled study using a compound of structural formula (I)
(Study Drug) administered "on demand" to patients with male
erectile dysfunction. The Study Drug was administered over a period
of eight weeks in the treatment of male erectile dysfunction (ED).
Erectile dysfunction (ED) is defined as the persistent inability to
attain and/or maintain an erection adequate to permit satisfactory
sexual performance. "On demand" dosing is defined as intermittent
administration of Study Drug prior to expected sexual activity.
[0192] The study population consisted of 212 men, at least 18 years
of age, with mild to severe erectile dysfunction. The Study Drug
was orally administered as tablets of coprecipitate made in
accordance with Butler U.S. Pat. No. 5,985,326. The Study Drug was
administered in 2 mg, 5 mg, 10 mg, and 25 mg doses, "on demand" and
not more than once every 24 hours. Treatment with all nitrates,
azole antifungals (e.g., ketoconazole or itraconazole), warfarin,
erythromycin, or antiandrogens was not allowed at any time during
the study. No other approved or experimental medications,
treatments, or devices used to treat ED were allowed. Forty-one
subjects were administered a placebo.
[0193] The two primary efficacy variables were the ability of a
subject to penetrate his partner and his ability to maintain an
erection during intercourse, as measured by the International Index
of Erectile Function (IIEF). The IIEF Questionnaire contains
fifteen questions, and is a brief, reliable measure of erectile
function. See R. C. Rosen et al., Urology, 49, pp. 822-830
(1997).
[0194] Secondary efficacy variables were IIEF domain scores for
erectile function, orgasmic function, sexual desire, intercourse
satisfaction, and overall satisfaction; the patient's ability to
achieve an erection, ability to insert his penis into his partner's
vagina, completion of intercourse with ejaculation, satisfaction
with the hardness of his erection, and overall satisfaction, all as
measured by the Sexual Encounter Profile (SEP) diary; and a global
assessment question asked at the end of the treatment period. The
SEP is a patient diary instrument documenting each sexual encounter
during the course of the study.
[0195] The safety analysis of the study included all enrolled
subjects, and was assessed by evaluating all reported adverse
events, and changes in clinical laboratory values, vital signs,
physical examination results, and electrocardiogram results.
[0196] At endpoint, patients who rated their penetration ability
(IIEF Question 3) as "almost always or always" were as follows:
17.5% in the placebo group, 38.1% in the 2 mg group, 48.8% in the
mg group, 51.2% in the 10 mg group, and 83.7% in the 25 mg group.
Comparisons revealed statistically significant differences in
change in penetration ability between placebo and all dose levels
of the Study Drug.
[0197] At endpoint, patients who rated their ability to maintain an
erection (IIEF Question 4) during intercourse as "almost always or
always" are as follows: 10.0% in the placebo group, 19.5% in the 2
mg group, 32.6% in the 5 mg group, 39.0% in the 10 mg group, and
69.0% in the 25 mg group. Comparison revealed statistically
significant differences in change in penetration ability between
placebo and the three higher dose levels of Study Drug.
[0198] Overall, this study demonstrated that all four doses of
Study Drug, namely 2 mg, 5 mg, 10 mg, and 25 mg, taken "on demand"
produced significant improvement, relative to placebo, in the
sexual performance of men with erectile dysfunction as assessed by
the IIEF, by patient diaries assessing frequency of successful
intercourse and intercourse satisfaction, and by a global
assessment. This improvement was demonstrated in a broad study
population that included patients who exhibited all severities of
erectile dysfunction. Most adverse events were mild or moderate in
severity. Significantly, no adverse events related to color vision
disturbances were reported by any patient.
[0199] The combined results from clinical studies showed that
administration of a compound of structural formula (I) effectively
treats male erectile dysfunction, as illustrated in the following
table.
7 IIEF ERECTILE FUNCTION DOMAIN (Change from Baseline) Unit Dose n
Mean .+-. SD p placebo 131 0.8 .+-. 5.3 2 mg 75 3.9 .+-. 6.1
<.001 5 mg 79 6.6 .+-. 7.1 <.001 10 mg 135 7.9 .+-. 6.7
<.001 25 mg 132 9.4 .+-. 7.0 <.001 50 mg 52 9.8 .+-. 5.5
<.001 100 mg 49 8.4 .+-. 6.1 <.001 n is number of subjects,
SD is standard deviation.
[0200] However, it also was observed from the combined clinical
studies that the percent of treatment-emergent adverse events
increased with an increasing unit dose of the compound of
structural formula (I), as illustrated in the following table.
8 Treatment-Emergent Adverse Events (%) Unit Dose (mg) Event
Placebo 2 5 10 25 50 100 Headache 10 12 10 23 29 34 46 Dyspepsia 6
3 14 13 19 20 25 Back Pain 5 3 3 15 18 24 22 Myalgia 3 0 3 9 16 20
29 Rhinitis 3 7 3 4 4 0 2 Conjunctivitis 1 0 1 1 0 2 5 Eyelid Edema
0 0 0 1 1 2 3 Flushing 0 0 0 <1 0 3 7 Vision 0 0 0 0 0 0 0
Abnormalities
[0201] The above table shows an increase in adverse events at 25 mg
through 100 mg unit doses. Accordingly, even though efficacy in the
treatment of ED was observed at 25 mg to 100 mg doses, the adverse
events observed from 25 mg to 100 mg doses must be considered.
[0202] In accordance with the present invention, a unit dose of
about 1 to about 20 mg, preferably about 2 to about 20 mg, more
preferably about 5 to about 20 mg, and most preferably about 5 to
about 15 mg, administered up to a maximum of 20 mg per 24-hour
period, both effectively treats ED and minimizes or eliminates the
occurrence of adverse side effects. Importantly, no vision
abnormalities were reported and flushing was essentially
eliminated. Surprisingly, in addition to treating ED in
individuals, with about 1 to about 20 mg unit dose of the compound
of structural formula (I), with a minimum of adverse side effects,
individuals undergoing nitrate therapy also can be treated for ED
by the method and composition of the present invention.
[0203] The principles, preferred embodiments, and modes of
operation of the present invention have been described in the
foregoing specification. The invention intended to be protected
herein, however, is not construed to be limited to the particular
forms disclosed, because they are to be regarded as illustrative
rather than restrictive. Variations and changes may be made by
those skilled in the art without departing from the spirit of the
invention.
* * * * *