U.S. patent application number 13/116484 was filed with the patent office on 2011-09-22 for compositions and kits for treating influenza.
This patent application is currently assigned to Adamas Pharmaceuticals, Inc.. Invention is credited to David Chernoff, Timothy J. Fultz, Jack Nguyen, Paul Spence, Gregory T. Went.
Application Number | 20110230432 13/116484 |
Document ID | / |
Family ID | 39759997 |
Filed Date | 2011-09-22 |
United States Patent
Application |
20110230432 |
Kind Code |
A1 |
Nguyen; Jack ; et
al. |
September 22, 2011 |
COMPOSITIONS AND KITS FOR TREATING INFLUENZA
Abstract
Compositions, kits and methods are provided for the treatment or
prophylaxis of influenza.
Inventors: |
Nguyen; Jack; (San
Francisco, CA) ; Went; Gregory T.; (Mill Valley,
CA) ; Spence; Paul; (San Diego, CA) ; Fultz;
Timothy J.; (Pleasant Hill, CA) ; Chernoff;
David; (San Rafael, CA) |
Assignee: |
Adamas Pharmaceuticals,
Inc.
Emeryville
CA
|
Family ID: |
39759997 |
Appl. No.: |
13/116484 |
Filed: |
May 26, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12040856 |
Feb 29, 2008 |
7981930 |
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13116484 |
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60918011 |
Mar 13, 2007 |
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60978099 |
Oct 5, 2007 |
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60989790 |
Nov 21, 2007 |
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Current U.S.
Class: |
514/43 |
Current CPC
Class: |
A61K 31/454 20130101;
A61K 31/7056 20130101; A61P 31/12 20180101; A61P 43/00 20180101;
A61K 31/7056 20130101; A61K 31/454 20130101; A61P 31/16 20180101;
A61K 2300/00 20130101; A61K 2300/00 20130101 |
Class at
Publication: |
514/43 |
International
Class: |
A61K 31/7056 20060101
A61K031/7056; A61P 31/16 20060101 A61P031/16 |
Claims
1. A method of preventing or treating influenza comprising
administering to a patient a therapeutically effective amount of a
combination of first, second and third antiviral agents comprising:
a) an M2 inhibitor; b) a second antiviral agent selected from the
group consisting of a replication inhibitor, an IMP dehydrogenase
inhibitor and an RNA polymerase inhibitor; and c) a neuraminidase
inhibitor (NAi); and wherein the combination increases the in vitro
sensitivity of one or more strains of an influenza A virus to at
least one of the antiviral agents by at least two fold.
Description
CROSS-REFERENCE
[0001] This application claims priority to U.S. application Ser.
No. 12/040,856, dated Feb. 29, 2008, which is incorporated herein
by reference in its entirety, and claims priority to: U.S.
Provisional Application No. 60/918,011, dated Mar. 13, 2007; U.S.
Provisional Application No. 60/978,099, dated Oct. 5, 2007; and
U.S. Provisional Application No. 60/989,790, dated Nov. 21, 2007;
each of the provisional applications is incorporated herein by
reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The field of the invention is antiviral combinations and
their use for the treatment or prophylaxis of influenza in a
patient.
[0003] Four antiviral drugs are currently approved by FDA to treat
acute, uncomplicated influenza. The M2 inhibitors amantadine
hydrochloride (SYMMETREL.RTM.) and rimantadine (FLUMADINE.RTM.) are
approved for treatment and prevention of influenza A. Both
amantadine and rimantadine are provided in 100 mg tablets and 50
mg/ml syrup for oral administration. The usual adult dose for both
drugs is 200 mg in two divided doses per day (BID). The pediatric
dose of amantadine in patients 1-9 years of age is 4.4 to 8.8
mg/kg/day, not to exceed 150 mg per day; for rimantadine, the dose
is 5 mg/kg administered once per day (QD), not to exceed 150 mg per
day.
[0004] The neuraminidase inhibitors zanamivir (RELENZA.RTM.) and
oseltamivir phosphate (TAMIFLU.RTM.) are approved for treatment and
prevention of influenza A and B. Zanamivir is provided for oral
inhalation only for use with an inhalation device. The recommended
dose of zanamivir for prophylaxis and treatment of influenza is 10
mg/day QD and 20 mg/day BID, respectively. Oseltamivir phosphate is
available as a capsule containing 75 mg oseltamivir for oral use,
and as a powder for oral suspension, which when constituted with
water as directed contains 12 mg/ml oseltamivir. The recommended
dose of oseltamivir for patients over 13 years old for prophylaxis
and treatment of influenza is 75 mg/day QD and 150 nag BID,
respectively.
[0005] Various combinations of antiviral drugs have been proposed
for treatment of influenza. U.S. Pat. No. 5,866,601 discloses
combining neuraminidase inhibitor compositions with antivirals
(such as amantadine, rimantadine and ribavirin). In vitro and in
vivo animal model studies on the effect of various dual
combinations of drugs against influenza have been reported (see
e.g. including combinations of ribavirin with amantadine (Wilson et
al., Antimicrob Agents Chemother (1980) 17:642-648; Hayden et al.,
Antimicrob Agents Chemother (1980) 18:536-41; and Burlington et
al., J. Antimicrob Chemother (1983) 11:7-14), rimantadine (Hayden
et al., supra; Galegov et al., Experientia (1977) 33:905-906; and
Madren et al., Antivir Chem Chemother (1995) 6:109-113), peramavir
(Smee et al., Chemotherapy (2002) 48:88-93), and oseltamivir (Smee
et al., Antiviral Chem Chemother (2006) 17:185-92); and
combinations of oseltamivir with amantadine (Ilyushina et al.,
Antiviral Res. (2006) 70:121-31) and rimantadine (Govorkova et al.,
Antimicrob Agents Chemother (2004) 48:4855-4863; Galabov et al.,
Antivir Chem Chemother (2006) 17:251-8; and Leneva et al.,
Antiviral Res (2000) 48:101-15). Several of these papers reported
that combinations of ribavirin and amantadine have additive to
synergistic effect against influenza virus compared to treatment
with the drugs singly (see e.g. Wilson et al., supra; Hayden et
al., supra; and Burlington et al., supra). In some of the studies,
the combination treatments are reported to have adverse results
compared to the monotherapy treatments. For example, the
combination of oseltamivir and rimantadine at low concentrations of
each drug was reported to result in an antagonistic interaction
against influenza A virus (Govorkova et al., supra). Smee et al.
(2006) reported that treatment of influenza A. virus-infected mice
with the combination of oseltamivir plus ribavirin was no better
than ribavirin used alone, and that when the treatments were
initiated three to four days post-infection, the groups treated
with the combination had fewer survivors than the animals treated
with ribavirin alone.
[0006] Viral resistance to the M2 inhibitors rimantadine and
amantadine can emerge rapidly during treatment because certain
single point mutations in the M2 protein can confer resistance to
both amantadine and rimantadine. In January 2006, CDC testing
revealed that a high proportion of influenza A viruses circulating
in the U.S. were resistant to amantadine and rimantadine, causing
the CDC to recommend against the use of these drugs for the
treatment and prophylaxis of Influenza (CDC Health Alert, Jan. 14,
2006). Currently, oseltamivir is considered a frontline treatment
for influenza A virus. However, oseltamivir-resistant strains have
been reported (de Jong et al., N Engi J. Med. (2005) 353:2667-72;
Euro Surveill. (2005)10(10):E051020.2) raising concerns that
transmissible, pathogenic resistant strains could reduce the
benefits of antiviral use in pandemic control (Lipsitch et al.,
PLoS Med (2007) January 23; 4(1):e15 [Epub ahead of print]).
Further, oseltamivir treatment has been linked to serious
neuropsychiatric events, especially in pediatric patients (see
Prescrire Int. (2006) 15:182-3).
[0007] In view of the foregoing, one object of the invention is to
provide improved therapeutics for treatment or prophylaxis of
influenza, particularly pandemic influenza and/or strains of
influenza that are resistant to an M2 inhibitor and/or a
neuraminidase inhibitor.
[0008] Another object of the invention is to provide improved
therapeutics for treatment or prophylaxis of influenza that prevent
the generation of drug-resistant strains within a patient or
population.
[0009] Another object of the invention is to provide improved
therapeutics for treatment or prophylaxis of influenza that have
significantly fewer or no adverse events or toxic effects compared
to current monotherapies.
SUMMARY OF THE INVENTION
[0010] One aspect of the invention is a composition for the
treatment or prophylaxis of influenza in a patient, said
composition comprising: 10-60 weight percent (wt. %), 25-50 wt. %,
.cndot. or 50-75 wt. % amantadine or rimantadine; and 30-80 wt. %,
50-75 wt. %, or 25-50 wt. % ribavirin or viramidine, wherein the
weight percents are based on the total weight of active agents in
the composition. In specific embodiments, the composition further
comprises 0.5-30 wt. % oseltamivir.
[0011] In one embodiment, the composition is in a formulation
suitable for oral or gastric administration, such as a liquid,
syrup, suspension, tablet, capsule, beads in capsules, or beads in
sachets. In a specific embodiment, the composition is in a unit
dosage form for oral administration comprising 25-125 mg amantadine
or rimantadine and 50-200 mg ribavirin or viramidine. In a specific
embodiment, the unit dosage form comprises at least 125 mg
amantadine in an extended release form, and less than 200 mg
ribavirin. In another embodiment the unit dosage form comprises
25-125 mg amantadine and 50-200 mg ribavirin.
[0012] In another embodiment, the composition is in a form suitable
for parenteral administration, such as a lyophilized powder, which
is reconstituted prior to administration, or a sterile liquid in a
vial.
[0013] Another aspect of the invention is a kit for the treatment
or prophylaxis of influenza in a patient comprising amantadine or
rimantadine, and ribavirin or viramidine, and optionally a
neuraminidase inhibitor such as oseltamivir, zanamivir, or
peramivir.
[0014] In a specific embodiment, a kit is provided for the oral
treatment or prophylaxis of influenza in a patient comprising a
plurality of dosage forms, said plurality constituting one or more
doses, each dose comprising a therapeutically or prophylactically
effective amount of a combination of ribavirin and amantadine. The
amantadine and ribavirin may be formulated as separate dosage forms
or co-formulated as single dosage forms. The amantadine may be in
an extended release form. In a specific embodiment, the amantadine
and ribavirin are formulated as separate dosage forms, with each
amantadine dosage form comprising 75-250 mg amantadine, and each
ribavirin dosage form comprising 50-200 or 100-400 mg ribavirin. In
various embodiments, the kit comprises an amantadine dosage form in
a dosage strength selected from 80 mg, 180 mg, and 330 mg, and a
ribavirin dosage form in a dosage strength selected from the group
consisting of 115 mg, 330 mg and 660 mg. In one embodiment, each
dose further comprises oseltamivir.
[0015] In another embodiment, the kit is provided for parenteral
treatment of influenza in a human patient, comprising amantadine in
a form suitable for parenteral administration; and ribavirin in a
form suitable for parenteral administration. The amantadine may be
contained in a plurality of first vials, and the ribavirin
contained in a plurality of second vials. Alternatively, the
amantadine and ribavirin are co-formulated and contained in a
plurality of vials. The kit may further comprise oseltamivir,
peramivir, or zanamivir in a form suitable for parenteral
administration.
[0016] Another aspect of the invention is a method for the
treatment or prophylaxis of influenza in a patient, said method
comprising: administering to the patient an effective amount of a
combination of three different antiviral agents having
corresponding three different mechanisms of action, selected from
the group consisting of influenza virus adsorption inhibitor, M2
inhibitor, IMP dehydrogenase inhibitor, RNA polymerase inhibitor,
influenza-specific interfering oligonucleotide, and neuraminidase
inhibitor.
[0017] In a specific embodiment, the method comprises administering
to the patient an effective amount of a combination of first,
second and third antiviral agents comprising: a) an M2 inhibitor
selected from the group consisting of rimantadine and amantadine;
b) an RNA polymerase inhibitor selected from the group consisting
of ribavirin and viramidine; and c) a neuraminidase inhibitor (NAi)
selected from the group consisting of oseltamivir, zanamivir, and
peramivir.
[0018] In a preferred embodiment the first and second antiviral
agents are administered in amounts that increase sensitivity of an
influenza virus to the third antiviral agent by at least 2-fold
over sensitivity of the virus to the third antiviral agent when
used as monotherapy. In a specific such embodiment, the first and
second antiviral agents are ribavirin and oseltamivir, and the
third antiviral agent is amantadine.
[0019] In one embodiment of the method, the antiviral agents are
administered to the patient by a method selected from the group
consisting of orally, parenterally, by inhalation, and combinations
thereof.
[0020] In a specific embodiment, the patient is administered
amantadine or rimantadine in an amount to maintain a plasma
concentration between 0.1 to 3 .mu.g/ml, 0.1 to 1.5 .mu.g/ml, or
0.3 to 1.5 .mu.g/ml for at least 48 continuous hours.
[0021] In another embodiment, the patient is administered
amantadine or rimantadine parenterally or orally in an amount of 5
to 500 mg/day, 20 to 250 mg/day, 100 to 800 mg/day, 100 to 600
mg/day, 200 to 700 mg/day, or 200 to 500 mg/day. When orally
administered, amantadine is optionally in an extended release
form.
[0022] In a further embodiment, the patient is administered
amantadine by intravenous infusion at a rate of 1 to 50 mg/hr, 3 to
40 mg/hr, or 5 to 30 mg/hr for at least 48 continuous hours.
[0023] In one embodiment, the patient is administered ribavirin or
viramidine in an amount to maintain a plasma concentration between
0.1 to 10.0 .mu.g/ml, 0.5 to 8 .mu.g/ml, 0.5 to 5.0 .mu.g/ml, 1 to
6 .mu.g/ml, 1 to 4 .mu.g/ml, 2 to 6 .mu.g/ml, 2 to 4 .mu.g/ml,
0.01-2 .mu.g/ml, or 0.2-2 .mu.g/ml for at least 48 continuous
hours. The patient is administered ribavirin parenterally or orally
in an amount of 50 to 2000 mg/day, 50 to 1600 mg/day, 100 to 1200
mg/day, 400 to 800 mg/day, 50 to 600 mg/day, 75 to 500 mg/day, or
75 to 200 mg/day.
[0024] In a specific embodiment, the patient is administered
ribavirin by intravenous infusion at a rate of 5 to 200 mg/hr, 10
to 150 mg/hr, 15 to 100, or 20 to 80 mg/hr for at least 48
continuous hours.
[0025] In a specific embodiment, wherein the patient is
administered amantadine or rimantadine in one of the
above-specified amounts together with ribavirin or viramidine in
one of the above-specified amounts, the patient is further
administered a neuraminidase inhibitor selected from the group
consisting of oseltamivir, oseltamivir carboxylate, zanamivir, and,
peramivir, in an amount to maintain a plasma concentration of the
neuratninidase inhibitor between 0.001-5 .mu.g/ml, 0.02 to 5
.mu.g/ml, 0.1 to 3 .mu.g/ml, 0.1 to 1 .mu.g/ml, 0.3 to 3 .mu.g/ml,
or 0.3 to 1 .mu.g/ml for at least 48 continuous hours.
[0026] In a specific embodiment, the patient is administered
zanamivir by intravenous infusion at a rate of 0.1 to 10 mg/hr, 0.4
to 7 mg/hr, or 1 to 5 mg/hr for at least 48 continuous hours.
[0027] In another embodiment, the patient is administered
oseltamivir by intravenous infusion at a rate of 0.1 to 20 mg/hr,
0.4 to 7 mg/hr, 1 to 7 mg/hr, 1 to 5 mg/hr, or 2 to 7 mg/hr for at
least 48 continuous hours.
[0028] In various embodiments, the patient may be administered
oseltamivir parenterally or orally in an amount of 10 to 150
mg/day, 10 to 50 mg/day, 50 to 100 mg/day, 75 to 150 mg/day, 150 to
300 mg/day, 100 to 500 mg/day, or 1 to 50 mg/day.
[0029] The invention provides a first antiviral agent, a second
antiviral agent and a third antiviral agent for simultaneous
separate or sequential administration, wherein the three agents
have corresponding three different mechanisms of action, selected
from the group consisting of influenza virus adsorption inhibitor,
M2 inhibitor, IMP dehydrogenase inhibitor, RNA polymerase
inhibitor, influenza-specific interfering oligonucleotide, and
neuraminidase inhibitor.
[0030] The invention also provides a first antiviral agent, a
second antiviral agent and a third antiviral agent for combined use
in therapy, wherein the three antiviral agents have corresponding
three different mechanisms of action, selected from the group
consisting of influenza virus adsorption inhibitor, M2 inhibitor,
IMP dehydrogenase inhibitor, RNA polymerase inhibitor,
influenza-specific interfering oligonucleotide, and neuraminidase
inhibitor.
[0031] The invention also provides a first antiviral agent, a
second antiviral agent and a third antiviral agent for combined use
in the treatment and/or prophylaxis of influenza infection, wherein
the three antiviral agents have corresponding three different
mechanisms of action, selected from the group consisting of
influenza virus adsorption inhibitor, M2 inhibitor, IMP
dehydrogenase inhibitor, RNA polymerase inhibitor,
influenza-specific interfering oligonucleotide, and neuraminidase
inhibitor.
[0032] The invention also provides the use of a first antiviral
agent, a second antiviral agent and a third antiviral agent in the
manufacture of a medicament for the treatment and/or prophylaxis of
influenza infection, wherein the three antiviral agents have
corresponding three different mechanisms of action, selected from
the group consisting of influenza virus adsorption inhibitor, M2
inhibitor, IMP dehydrogenase inhibitor, RNA polymerase inhibitor,
influenza-specific interfering oligonucleotide, and neuraminidase
inhibitor. As described below, the three agents may be administered
separately from each or in double or triple combinations.
[0033] The invention also provides the use of an antiviral agent in
the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection, wherein the antiviral agent is
selected from the group consisting of influenza virus adsorption
inhibitors, M2 inhibitors, IMP dehydrogenase inhibitors, RNA
polymerase inhibitors, influenza-specific interfering
oligonucleotides, and neuraminidase inhibitors, and wherein the
medicament is prepared for administration (or is administered) to a
patient in combination with two further antiviral agents, wherein
the three antiviral agents have different mechanisms of action,
selected from the group consisting of influenza virus adsorption
inhibitor, M2 inhibitor, IMP dehydrogenase inhibitor, RNA
polymerase inhibitor, influenza-specific interfering
oligonucleotide, and neuraminidase inhibitor.
[0034] The invention also provides the use of a first antiviral
agent in the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection, wherein the medicament is
prepared for administration (or is administered) to a patient in
combination with a second antiviral agent and a third antiviral
agent, wherein: a) the first antiviral agent is selected from the
group consisting of influenza virus adsorption inhibitor and M2
inhibitor; b) the second antiviral agent is selected from the group
consisting of IMP dehydrogenase inhibitor, and RNA polymerase
inhibitor; and c) the third antiviral agent is selected from the
group consisting of interfering oligonucleotide and neuraminidase
inhibitor.
[0035] The invention also provides the use of a second antiviral
agent in the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection, wherein the medicament is
prepared for administration (or is administered) to a patient in
combination with a first antiviral agent and a third antiviral
agent, wherein: a) the first antiviral agent is selected from the
group consisting of influenza virus adsorption inhibitor and M2
inhibitor; b) the second antiviral agent is selected from the group
consisting of IMP dehydrogenase inhibitor, and RNA polymerase
inhibitor; and c) the third antiviral agent is selected from the
group consisting of interfering oligonucleotide and neuraminidase
inhibitor.
[0036] The invention also provides the use of a third antiviral
agent in the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection, wherein the medicament is
prepared for administration (or is administered) to a patient in
combination with a first antiviral agent and a second antiviral
agent, wherein: a) the first antiviral agent is selected from the
group consisting of influenza virus adsorption inhibitor and M2
inhibitor; b) the second antiviral agent is selected from the group
consisting of IMP dehydrogenase inhibitor, and RNA polymerase
inhibitor; and c) the third antiviral agent is selected from the
group consisting of interfering oligonucleotide and neuraminidase
inhibitor.
[0037] The invention also provides the use of a first and a second
antiviral agent in the manufacture of a medicament for the
treatment and/or prophylaxis of influenza infection, wherein the
medicament is prepared for administration (or is administered) to a
patient in combination with a third antiviral agent, wherein: a)
the first antiviral agent is selected from the group consisting of
influenza virus adsorption inhibitor and M2 inhibitor; b) the
second antiviral agent is selected from the group consisting of IMP
dehydrogenase inhibitor, and RNA polymerase inhibitor; and c) the
third antiviral agent is selected from the group consisting of
interfering oligonucleotide and neuraminidase inhibitor.
[0038] The invention also provides the use of one or more antiviral
agent(s) in the manufacture of a medicament for the treatment
and/or prophylaxis of influenza infection, wherein the antiviral
agents have different mechanisms of action, selected from the group
consisting of influenza virus adsorption inhibitor, M2 inhibitor,
IMP dehydrogenase inhibitor, RNA polymerase inhibitor,
influenza-specific interfering oligonucleotide, and neuraminidase
inhibitor, and wherein the medicament is prepared for
administration (or is administered) to a patient in combination
with one or more further antiviral agents such that the patient
receives three antiviral agents having different mechanisms of
action selected from said group.
[0039] The invention also provides the use of an antiviral agent in
the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection in a patient, wherein the
antiviral agent is selected from the group consisting of influenza
virus adsorption inhibitors, M2 inhibitors, IMP dehydrogenase
inhibitors, RNA polymerase inhibitors, influenza-specific
interfering oligonucleotides, and neuraminidase inhibitors, and
wherein the patient has previously been treated with at least two
further antiviral agents, wherein said antiviral agents have
different mechanisms of action, said different mechanisms of action
being selected from the group consisting of influenza virus
adsorption inhibitor, M2 inhibitor, IMP dehydrogenase inhibitor,
RNA polymerase inhibitor, influenza-specific interfering
oligonucleotide, and neuraminidase inhibitor.
[0040] The invention also provides the use of a first antiviral
agent in the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection in a patient, wherein the
patient has previously been treated with a second antiviral agent
and, optionally, a third antiviral agent, wherein: a) the first
antiviral agent is selected from the group consisting of influenza
virus adsorption inhibitor and M2 inhibitor; b) the second
antiviral agent is selected from the group consisting of IMP
dehydrogenase inhibitor, and RNA polymerase inhibitor; and c) the
third antiviral agent is selected from the group consisting of
interfering oligonucleotide and neuraminidase inhibitor.
[0041] The invention also provides the use of a second antiviral
agent in the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection in a patient, wherein the
patient has previously been treated with a first antiviral agent
and, optionally, a third antiviral agent, wherein: a) the first
antiviral agent is selected from the group consisting of influenza
virus adsorption inhibitor and M2 inhibitor; b) the second
antiviral agent is selected from the group consisting of IMP
dehydrogenase inhibitor, and RNA polymerase inhibitor; and c) the
third antiviral agent is selected from the group consisting of
interfering oligonucleotide and neuraminidase inhibitor.
[0042] The invention also provides the use of a third antiviral
agent in the manufacture of a medicament for the treatment and/or
prophylaxis of influenza infection in a patient, wherein the
patient has previously been treated with a first antiviral agent
and a second antiviral agent, wherein: a) the first antiviral agent
is selected from the group consisting of influenza virus adsorption
inhibitor and M2 inhibitor; b) the second antiviral agent is
selected from the group consisting of IMP dehydrogenase inhibitor,
and RNA polymerase inhibitor; and c) the third antiviral agent is
selected from the group consisting of interfering oligonucleotide
and neuraminidase inhibitor.
[0043] In these uses, the previous treatment of the patient will
typically have been no more than 7 days prior to administration of
said medicament (e.g. in the previous 7, 6, 5, 4, 3, 2 days, or in
the previous 24 hours).
[0044] The invention also provides an antiviral agent for use in
the treatment and/or prophylaxis of influenza infection, wherein
the antiviral agent is selected from the group consisting of
influenza virus adsorption inhibitors, M2 inhibitors, IMP
dehydrogenase inhibitors, RNA polymerase inhibitors,
influenza-specific interfering oligonucleotides, and neuraminidase
inhibitors, and wherein the antiviral agent is administered (or is
prepared for administration) with at least one further antiviral
agent, wherein said antiviral agents have different mechanisms of
action, said different mechanism of action being selected from the
group consisting of influenza virus adsorption inhibitor, M2
inhibitor, IMP dehydrogenase inhibitor, RNA polymerase inhibitor,
influenza-specific interfering oligonucleotide, and neuraminidase
inhibitor.
[0045] The invention also provides a first antiviral agent for use
in the treatment and/or prophylaxis of influenza infection, wherein
the first antiviral agent is administered (or is prepared for
administration) with a second antiviral agent and, optionally, a
third antiviral agent, wherein: a) the first antiviral agent is
selected from the group consisting of influenza virus adsorption
inhibitor and M2 inhibitor; b) the second antiviral agent is
selected from the group consisting of IMP dehydrogenase inhibitor,
and RNA polymerase inhibitor; and c) the third antiviral agent is
selected from the group consisting of interfering oligonucleotide
and neuraminidase inhibitor.
[0046] The invention also provides a second antiviral agent for use
in the treatment and/or prophylaxis of influenza infection, wherein
the second antiviral agent is administered (or is prepared for
administration) with a first antiviral agent and, optionally, a
third antiviral agent, wherein: a) the first antiviral agent is
selected from the group consisting of influenza virus adsorption
inhibitor and M2 inhibitor; b) the second antiviral agent is
selected from the group consisting of IMP dehydrogenase inhibitor,
and RNA polymerase inhibitor; and c) the third antiviral agent is
selected from the group consisting of interfering oligonucleotide
and neuraminidase inhibitor.
[0047] The invention also provides a third antiviral agent for use
in the treatment and/or prophylaxis of influenza infection, wherein
the third antiviral agent is administered (or is prepared for
administration) with a first antiviral agent and a second antiviral
agent, wherein: a) the first antiviral agent is selected from the
group consisting of influenza virus adsorption inhibitor and M2
inhibitor; b) the second antiviral agent is selected from the group
consisting of IMP dehydrogenase inhibitor, and RNA polymerase
inhibitor; and c) the third antiviral agent is selected from the
group consisting of interfering oligonucleotide and neuraminidase
inhibitor.
INCORPORATION BY REFERENCE
[0048] All publications, patents, and patent applications mentioned
in this specification are herein incorporated by reference to the
same extent as if each individual publication, patent, or patent
application was specifically and individually indicated to be
incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The novel features of the invention are set forth with
particularity in the appended claims. A better understanding of the
features and advantages of the present invention will be obtained
by reference to the following detailed description that sets forth
illustrative embodiments, in which the principles of the invention
are utilized, and the accompanying drawings of which:
[0050] FIGS. 1A-4 are plan views of six different respective
blister packs comprising dosage forms according to different
embodiments of the present invention.
[0051] FIG. 5 is a synergy volume plot of the data generated from
the experiment described in Example 1B.
DETAILED DESCRIPTION OF THE INVENTION
[0052] The invention provides methods, uses, compositions, and kits
for treatment of a human patient having an influenza virus
infection or suspected of being infected with or at risk of
exposure to influenza virus. The invention can be used to prevent
or reduce the probability of the generation of drug resistant
strains, to treat a human patient suspected of being infected with
or at risk of exposure to a drug-resistant influenza virus, and to
minimize side-effects and toxicity associated with monotherapy.
[0053] One aspect of the invention is a method for the treatment or
prophylaxis of influenza in a patient to reduce or prevent symptoms
associated with influenza virus infection. The patient can be human
or any other animal susceptible to influenza infection (e.g.
domestic animals such as cats and dogs; livestock and farm animals
such as horses, cows, pigs, chickens, etc.). Medical care standards
are used to determine that that a patient is likely infected with
influenza virus or is at risk of exposure to influenza virus. The
influenza virus can be an A or B virus. In specific embodiments,
the virus is an influenza A virus (e.g. H1N1, H1N2, H2N2, H3N2,
H5N1, H7N7, H9N2, etc.).
[0054] The method comprises administering to the patient a
combination of three different antiviral agents (referred to herein
as a "triple combination") having corresponding three different
mechanisms of action selected from the group consisting of
influenza virus adsorption inhibitor, M2 inhibitor, IMP
dehydrogenase inhibitor, RNA polymerase inhibitor,
influenza-specific interfering oligonucleotide, and neuraminidase
inhibitor. One or more additional antiviral agents may be added to
the triple combination (e.g. a fourth antiviral agent having a
mechanism of action that differs from the three mechanisms of the
triple combination or that is the same as one of mechanisms of
triple combination). References herein to specific antiviral agents
(e.g. amantadine, oseltamivir, etc.) are intended to include
pharmaceutically acceptable salts of the antiviral agents (e.g.
amantadine hydrochloride, oseltamivir phosphate, etc.).
[0055] The antiviral agents are preferably administered at relative
ratios and dosages demonstrated to be additive or synergistic with
respect to a reduction in viral load, symptoms, duration of
illness, prevention of drug-resistant strains, etc. Synergy is when
the efficacy of the combination is greater than the cumulative
efficacy of each drug within the combination as single agents
(Prichard and Shipman, Antiviral Res. (1990) 14:181-206). Methods
for measuring drug synergy of antiviral agents are described in the
Examples below, and are generally known in the art (see e.g.
Schinazi et al., Antimicrob Agents Chemother. (1982) 22:499-507;
and Prichard and Shipman, supra; and Prichard et al., Antibicrob
Agents Chemother (1993) 37:540-545; each incorporated herein by
reference). FIG. 5 depicts a three-dimensional synergy plot of data
obtained from the experiment described in Example 1B below; the
analysis was made using methods described by Prichard et al.
(1993), supra.
[0056] The use of synergistic amounts of the antiviral agents
provides greater efficacy and/or allows lower amounts of one or
more of the drugs to be used than that used in current monotherapy,
thereby resulting in fewer side-effects for the patient and
permitting the production of more treatment doses from finite
amount of bulk drug. In a specific embodiment, the combination
increases the sensitivity of one or more strains of an influenza
virus to at least one of the antiviral agents by at least 2-fold,
5-fold, 10-fold, 20-fold, 50-fold, or 100-fold compared to the
sensitivity of the virus to the drug when used as a monotherapy.
For example, when a drug has an EC.sub.50 of 1.0 .mu.g/ml against
an influenza virus when used as a monotherapy as determined by in
vitro testing, and has an EC.sub.50 of 0.01 .mu.g/ml or less when
used in combination with two other antiviral agents, the
combination is said to increase the sensitivity of the influenza
virus to the drug by at least 100-fold. Preferably, the sensitivity
of two or all three drugs in the combination is improved by at
least 2-fold, 5-fold, 10-fold, 20-fold, 50-fold, or 100-fold.
Example 1B below describes an in vitro assay for determining how
increases in drug sensitivity can be determined using an H3N2
influenza strain. The same assay can be used to measure drug
sensitivity against other influenza strains. In the absence of
synergy, combinations of antivirals may still be beneficial due to
the additive contribution of each drug within the combination and
the overall efficacy of the combination without added toxicity.
[0057] Use of the triple combination significantly reduces the
probability of the generation of drug resistant strains compared to
prior monotherapies. This is particularly advantageous-in the
treatment of influenza in a pandemic or localized outbreak.
Further, the triple combination can be used to treat a human
patient infected with or at risk of exposure to a drug-resistant
influenza virus. Because rapid viral genotyping is not usually
available on a real time basis to clinicians allowing rationale
drug selection based on resistance profiles, the invention provides
for broad and effective anti-viral coverage even in the absence of
these data. In specific embodiments, the drug-resistant influenza
Virus is resistant to one of the drugs of the combination used.
Surprisingly, treatment with the triple combination provides a
greater anti-influenza effect against the drug-resistant virus than
treatment that is the same except for the exclusion of the drug to
which the virus is resistant as a monotherapy. Standard medical
procedures are used to assess the likelihood that a patient is
infected with or is at risk of exposure to a drug-resistant virus
(e.g. via guidance of CDC Health Alerts, etc.).
[0058] Preferably each drug in the combination is active at a
different phase in the influenza virus life cycle. For example,
influenza virus adsorption inhibitors and M2 inhibitors are active
at the beginning of the lifecycle; IMP dehydrogenase inhibitors and
RNA polymerase inhibitors are active at the middle of the
lifecycle; and interfering oligonucleotides and neuraminidase
inhibitors are active at the end of the lifecycle.
[0059] Examples of influenza virus adsorption inhibitors include
hemagglutinin-specific monoclonal antibodies (see e.g. Palladino et
al., J. Virol. (1995) 69:2075-81), polyoxometalates (see e.g.
Shigeta et al., Antimicrob Agents Chemother. (1997) 41:1423-7),
sulfated polysaccharides, sialidase fusion proteins (e.g. Fludase),
and 0-glycosides of sialic acid (see e.g. Guo et al, Glycobiology
(2002) 12:183-90). These and other influenza adsorption inhibitors
are known in the art (see e.g. Combating the Threat Of Pandemic
Influenza: Drug Discovery Approaches, Ed. Paul F. Torrence, John
Wiley And Sons Ltd (2007), incorporated herein by reference).
[0060] Examples of M2 inhibitors include amino-adamantane compounds
such as amantadine (1-amino-adamantane), rimantadine
(1-(1-aminoethyl)adamantane),
spiro[cyclopropane-1,2'-adamantan]-2-amine,
spiro[pyrrolidine-2,2'-adamantane],
spiro[piperidine-2,2'-adamantane], 2-(2-adamantyppiperidine,
3-(2-adamantyl)pyrrolidine, 2-0-adamantyppiperidine,
2-(1-adamantyl)pyrrolidine, and
2-(1-adamantyl)-2-methyl-pyrrolidine; and M2-specific monoclonal
antibodies (see e.g. US 20050170334; and Zebedee and Lamb, J Virol.
(1988) 62:2762-72). In a preferred embodiment, one of the antiviral
agents in the triple combination is amantadine or rimantadine.
[0061] Examples of IMP dehydrogenase inhibitors include ribavirin,
viramidine (a prodrug of ribavirin), and merimepodib (VX-497; see
e.g. Markland et al., Antimicrob Agents Chemother. (2000)
44:859-66).
[0062] As used herein, the term RNA polymerase inhibitor refers to
an antiviral agent that inhibits the polymerase, protease, and/or
endonuclease activity of the viral RNA polymerase complex or one of
its subunits (i.e. PB1, PB2 and PA). Exemplary RNA polymerase
inhibitors include antiviral nucleoside analogs such as ribavirin,
viramidine, 6-fluoro-3-hydroxy-2-pyrazinecarboxamide (T-705),
2'-deoxy-2'-fluoroguanosine, pyrazofurin, 3-deazaguanine, carbodine
(see e.g. Shannon et al., Antimicrob Agents Chemother. (1981)
20:769-76), and cyclopenenyl cytosine (see e.g. Shigeta et al.,
Antimicrob Agents Chemother. (1988) 32:906-11); and the
endonuclease inhibitor flutimide (see e.g. Tomassini et al.,
Antimicrob Agents Chemother. (1996) 40:1189-93). In a preferred
embodiment, one of the antiviral agents in the triple combination
is ribavirin or viramidine.
[0063] Examples of influenza-specific interfering oligonucleotides
include siRNAs (see e.g. Zhou et al., Antiviral Res. (2007)
76:186-93), antisense oligonucleotides, phosphorothioate
oligonucleotides, ribozymes (see e.g. U.S. Pat. No. 6,258,585 to
Draper), morpholino oligomers and peptide nucleic acids (see e.g.
Schubert and Kurreck, Handb Exp Pharmacol. (2006) 173:261-87).
[0064] Examples of neuraminidase inhibitors include oseltamivir,
oseltamivir carboxylate (GS4071; see e.g. Eisenberg et al.,
Antimicrob Agents Chemother. (1997) 41:1949-52), zanamivir,
peramivir (RWJ-27021; BXC-1812, BioCryst),
2,3-didehydro-2-deoxy-N-acetylneuraminic acid (DANA),
2-deoxy-2,3-dehydro-N-trifluoroacetylneuraminic acid (FANA),
A-322278, and A-315675 (see U.S. Pat. No. 6,455,571 to Maring et
al, and Kati et al., Antimicrob Agents Chemother. (2002)
46:1014-21). In a preferred embodiment, one of the antiviral agents
in the triple combination is oseltamivir, peramivir, or
zanamivir.
[0065] In one embodiment, the first antiviral agent is an M2
inhibitor, preferably amantadine; the second antiviral agent is an
antiviral nucleoside analog, preferably ribavirin or viramidine;
and the third antiviral agent is a neuraminidase inhibitor,
preferably oseltamivir or zanamivir. In other embodiment, the first
antiviral agent is amantadine or rimantadine; the second antiviral
agent is ribavirin or viramidine, and the third antiviral agent is
oseltamivir, oseltamivir carboxylate, peramivir or zanamivir.
[0066] Each antiviral agent of the combination is administered
using one or more routes of administration suitable for the
particular agent (e.g. orally, parenterally, by inhalation,
transdermally, intranasally, gastric administration (e.g. via G-,
NG-, J-, etc. feeding tubes), etc.). In various embodiments, the
antiviral agents are prepared for oral administration and/or
gastric administration (e.g. via feeding tubes) as liquids, syrups,
suspensions, tablets, capsules, beads in capsules, or beads in
sachets. In some embodiments, at least one of the antiviral agents
is administered by one route of administration (e.g. parenterally),
and at least one of the antiviral agents is administered by an
alternate route of administration (e.g. orally or by
inhalation).
[0067] In oral dosing embodiments, one or more of the antiviral
agents may be provided in an immediate release (IR) or extended
release (ER) form. The preparation of ER dosage forms (also
referred to in the art as "controlled release", "sustained
release", and "modified release" dosage forms) is well known.
Suitable M2 inhibitor ER dosage forms are described in U.S. Ser.
No. 11/285,905 and U.S. Ser. No. 11/399,879, both to Went et al.,
the contents of which are incorporated herein by reference. The
antiviral agents maybe administered as separate formulations,
simultaneously, or sequentially. Alternatively two or more of the
antiviral agents may be provided as combination compositions in
single dosage forms.
[0068] When treating an established influenza virus infection in a
patient presenting with symptoms of vomiting and/or diarrhea,
parenteral administration is particularly preferred, as oral
administration may not be effective in rapidly achieving the
desired plasma concentrations of the antiviral agents. Preferably,
the parenteral administration is selected from intravenous
infusion, intravenous injection, or intramuscular injection. Most
preferred is intravenous infusion. A preferred kit for parenteral
administration comprises an M2 inhibitor (amantadine or
rimantadine), an antiviral nucleoside analogue (ribavirin or
viramidine), and optionally a neuraminidase inhibitor (oseltamivir,
oseltamivir carboxylate, or zanamivir), which are parenterally
administered together with a pharmaceutically acceptable carrier in
a single pharmaceutical composition. In other embodiments, the M2
inhibitor, the antiviral nucleoside analogue, and optionally the
neuraminidase inhibitor, are parenterally administered as separate
dosage forms. In some embodiments, at least one of the M2
inhibitor, the antiviral nucleoside analogue, and the neuraminidase
inhibitor, if present, is initially provided in the form of a
lyophilized composition which is reconstituted with a
pharmaceutically acceptable carrier prior to parenteral
administration. In some-embodiments, the M2 inhibitor, the
antiviral nucleoside analogue and the neuraminidase inhibitor, if
present, are each initially provided in a separate container, and
thereafter are combined with a pharmaceutically acceptable carrier
prior to parenteral administration. In some embodiments, one of the
antiviral agents may be provided in lyophilized form which is
reconstituted by a liquid formulation of one of the other antiviral
agents.
[0069] The plasma concentration of each drug of the triple
combination is preferably maintained between a desired C.sub.min
and C.sub.max for at least 24, 48, 72, 96, 120, 144, or 168
continuous hours. Routine clinical trials are used to determine the
average C.sub.min, C.sub.max, and Cmean plasma concentrations of a
patient population by various dosing regimens. The duration of the
therapy is typically 5-10 days for treatment, or until the virus
has cleared from the patient. For prophylaxis, the daily dose of
the antiviral agents administered is typically 50% that used for
treatment and is administered over the course of two or more weeks,
typically up to about 6 weeks or more until the risk of infection
abates.
[0070] The invention is further exemplified below with respect to
uses of specific antiviral agents and combinations of antiviral
agents, and the dosages and concentrations at which they are used.
Suitable dosages and concentrations of other antiviral agents that
are not further exemplified below can be determined using
information available in the literature and by routine
experimentation, such as described in the examples below and known
generally in the art.
[0071] In a specific embodiment of the invention, the first
antiviral agent of the triple combination is amantadine or
rimantadine, which is administered to the patient in an amount that
maintains a plasma concentration of the amantadine or rimantadine
between 0.05 .mu.g/ml (C.sub.min) to 5.0 .mu.g/ml (C.sub.max),
preferably 0.1 to 3.0 .mu.g/ml, more preferably 0.1 to 1.5
.mu.g/ml, and most preferably 0.3 to 1.5 is/ml for at least 48
continuous hours. The desired plasma concentration can be achieved
by administering the amantadine or rimantadine parenterally or
orally in an amount of 5 to 500 mg/day, 20 to 250 mg/day, 100 to
800 mg/day, 100 to 600 mg/day, 200 to 700 mg/day, or 200 to 500
mg/day. Particularly preferred daily oral dosages of rimantadine
range from about 50-400 mg/day, 75-300 mg/day, 100-250 mg/day, or
100-200 mg/day.
[0072] In some embodiments, exemplary amantadine and rimantadine
oral dosage forms contain at least about 25, 50, 75, 100, 125, 150,
175 or 200 mg per dosage form and up to about 75, 100, 125, 150,
175, 200, 225, 250, 275, 300, 350, or 400 mg per dosage form. One,
two, three or four of said dosage forms may be administered one or
two times per day for prophylaxis or treatment. The resulting daily
doses may be at least 25, 50, 75, 100, 125, 150, 175 or 200 mg per
day and up to about and up to about 75, 100, 125, 150, 175, 200,
225, 250, 275, 300, 325, 350, 400, 450, 500, 550, 600, 650, 700,
750 or 800 mg/day. In one exemplary treatment, the patient
self-administers two 125 mg amantadine ER unit dosage forms (e.g.
capsules or tablets) every twelve hours (i.e. BID) for a total of
about 500 mg/day amantadine, typically taken in combination with
ribavirin as described below. Also in this example, the
prophylactic dose is one 125 mg ER dosage form BID.
[0073] For oral administration of 200 mg/day or more of amantadine
or rimantadine, ER formulations are preferred as they allow for
lower C.sub.max/C.sub.min ratios, thereby optimizing the time that
the M2 inhibitor concentrations remain above ED.sub.50, while
minimizing toxicity. In a preferred ER formulation, the amantadine
or rimantadine has an in vitro dissolution profile of less than
about 70 wt. % in one hour, less than about 90 wt. % in two hours,
greater than about 40 wt. % in six hours and greater than about 85
wt. % in 12 hours, as measured using a USP type 2 (paddle)
dissolution system at 50 rpm, at a temperature of
37.sup..perp.0.5.degree. C. with 500 ml water as a dissolution
medium. Further preferred is an ER formulation of amantadine or
rimantadine with an in vitro dissolution profile of less than 20 wt
% in one hour, less than about 50% in two hours, greater than about
40% in six hours, and greater than about 90% in twelve hours as
measured above. This reduction in dissolution may advantageously
reduce the interdose variability in plasma concentration for the
active agent or improve tolerability of the active agent,
especially when the administration is BID or QD. In certain
embodiments, the amantadine or rimantadine is in an oral dosage
form and has a T.sub.max of at least 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, or 20 hours.
[0074] In a specific embodiment, the patient is administered
amantadine by intravenous infusion at a rate of 1 to 50 mg/hr, 3 to
40 mg/hr, or 5 to 30 mg/hr for at least 48, 72, or 96 continuous
hours.
[0075] In one embodiment of the invention, the second antiviral
agent of the triple combination is ribavirin or viramidine. In a
preferred embodiment, the ribavirin or viramidine is administered
together with amantadine or rimantadine in the above-mentioned
amounts. The ribavirin or viramidine is administered to the patient
in an amount to achieve a plasma concentration of 0.1 .mu.g/ml
(C.sub.min) to 10.0 .mu.g/ml (C.sub.max), 0.5 to 8 .mu.g/ml, 0.5 to
5 .mu.g/ml, 1 to 6 .mu.g/ml, 1 to 4 .mu.g/ml, 2 to 6 .mu.g/ml, 2 to
4 .mu.g/ml, 0.01-2 .mu.g/ml, or 0.2-2.0 .mu.g/ml for at least 48,
72, or 96 continuous hours. The desired plasma concentration can be
achieved by administering the ribavirin parenterally or orally in
an amount of 50 to 2400 mg/day, 50 to 2000 mg/day, 50 to 1600
mg/day, 100 to 1200 mg/day, 400 to 800 mg/day, 50 to 600 mg/day, 75
to 500 mg/day, or 75 to 200 mg/day. In a preferred embodiment, the
ribavirin or viramidine is administered at low daily dosages that
have additive or synergistic effect when administered in
combination amantadine or rimantadine and a neuraminidase inhibitor
such as oseltamivir, peramivir, or zanarmivir. The low dosages are
typically about 10-800 mg/day, 25-600 mg/day, 50-600 mg/day, and
preferably about 75-500 mg/day. In one exemplary treatment, the
patient self-administers one 160 mg ribavirin unit dosage form BID
for a total of 320 mg/day ribavirin.
[0076] In a specific embodiment, ribavirin or viramidine is
administered orally in amounts of at least about 10, 25, 30, 40,
50, 75, 100, 125, 150, 175 or 200 mg per dosage form and up to
about 150, 175, 200, 250, 300, 350, 400, 450 or 500 mg per dosage
form. One, two, three or four of said dosage forms may be
administered one or two times per day for prophylaxis or treatment.
The resulting daily doses may be at least 10, 25, 30, 40, 50, 75,
100, 125, 150, 175 or 200 mg per day and up to about 100, 125, 150,
175, 200, 225, 250, 275, 300, 325, 350, 400, 450, 500, 550, 600,
650, 700, 750, 800, 1200, 1600, or 2000 mg/day. In one exemplary
treatment, the patient self-administers 2.times.200 mg dosage forms
BID for a total of about 800 mg per day. Also in this example, the
prophylactic dose is 1.times.200 mg dosage form BID.
[0077] The ribavirin or viramidine (and optionally one or both of
the other antiviral agents) may be administered initially in
loading dose amount, and thereafter administered in a daily
maintenance dose amount, wherein the loading dose amount is about
1.5 to about 3 times the daily maintenance dose amount. The loading
dose may be administered by a route that is the same as or
different from that of the subsequent maintenance dose. The loading
dose is preferably administered parenterally or orally, and most
preferably parenterally. Preferably, the loading dose is
administered as an intravenous infusion, intravenous injection, or
intramuscular injection. With intravenous infusion, the loading
dose may be achieved by using a higher, concentration of the
antiviral agent in the first i.v. bag infused into the patient.
Alternatively, the initial i.v. infusion bag may have the same
concentration of active agents as the subsequent i.v. bags, but be
administered with an increased rate of infusion (e.g. 3-6 hrs
compared to 8 hrs).
[0078] In a specific embodiment, the patient is administered
ribavirin or viramidine by intravenous infusion at a rate of 5 to
200 mg/hr, 10 to 150 mg/hr, 15 to 100, or 20 to 80 mg/hr for at
least 48, 72, or 96 continuous hours.
[0079] In a particular embodiment of the invention, ribavirin or
viramidine is administered together with amantadine and oseltamivir
in the treatment of an influenza virus that is resistant to
amantadine or oseltamivir monotherapy.
[0080] In one embodiment of the invention, the third antiviral
agent of the triple combination is a neuraminidase inhibitor
selected from the group consisting of oseltamivir, oseltamivir
carboxylate, zanamivir, and peramivir. Oseltamivir and zanamivir
are particularly preferred.
[0081] The neuraminidase inhibitor, preferably oseltamivir or
zanamivir, is administered to the patient in an amount to achieve a
plasma concentration between 0.001 to 5 .mu.g/ml, 0.02 .mu.g/ml to
5 .mu.g/ml 0.1 to 3 .mu.g/ml, 0.1 to 1 .mu.g/ml, 0.3 to 3 .mu.g/ml,
0.3 to 1 .mu.g/ml, 0.001 to 0.1 .mu.g/ml, or 0.0001 to 0.01
.mu.g/ml for at least 48, 72, or 96 continuous hours. The desired
plasma concentration may be achieved by administering oseltamivir
parenterally or orally in an amount of 10 to 150 mg/day, 10 to 50
mg/day, 50 to 100 mg/day, 75 to 150 mg/day, 150 to 300 mg/day, or
100 to 500 mg/day. Zanamivir is typically administered in an amount
of 25-150 mg/day, preferably 40-100 mg/day.
[0082] In a preferred embodiment, the neuraminidase inhibitor is
administered at low daily dosages that have additive or synergistic
effect when administered in combination with amantadine and
ribavirin or viramidine. In specific embodiments, synergistic
effect is achieved when plasma concentrations of 0.15-1.5 .mu.g/ml
amantadine, 0.0001-0.01 .mu.g/ml oseltamivir, and 0.6-6 .mu.g/ml
ribavirin are maintained in the patient for at least 48, 72, or 96
continuous hours. Specific dosages that achieve these plasma
concentrations are determined using routine calculations and
confirmed by clinical trials. The low dosages of oseltamivir are
typically about 1-50 mg/day, preferably about 1-25 mg/day, and more
preferably about 2.5-10 mg/day. In one exemplary treatment, a
patient self-administers a unit dosage form of 25 mg oseltamivir
taken QD or BID. In preferred embodiments, oseltamivir in any of
the above dosages is taken in combination with any of the
above-described amounts of amantadine and ribavirin. In a specific
embodiment, 25 mg of oseltamivir is taken QD or BID together with
160 mg amantadine and 160 mg ribavirin (either in separate unit
dosage forms, or in a combination unit dosage form) which are also
taken QD or BID. In another specific embodiment, 75 mg oseltamivir
is taken QD or BID together with 100 mg amantadine QD or BID and
600 mg ribavirin QD or BID.
[0083] In a specific embodiment, the patient is administered
oseltamivir by intravenous infusion at a rate of 0.1 to 20 mg/hr,
0.4 to 7 mg/hr, 1 to 7 mg/hr, 1 to 5 mg/hr, or 2 to 7 mg/hr for at
least 48, 72, or 96 continuous hours. The desired plasma
concentration of zanamivir may be achieved by parenteral
administration in an amount of 5 to 250 mg/day, 10 to 200 mg/day,
or 25 to 150 mg/day. In a specific embodiment, the patient is
administered zanamivir by intravenous infusion at a rate of 0.1 to
10 mg/hr, 0.4 to 7 mg/hr, or 1 to 5 mg/hr for at least 48, 72, or
96 continuous hours.
[0084] In a specific embodiment, the patient is administered
oseltamivir orally in an amount of 1 to 75 mg/day, 1 to 50 mg/day,
1 to 25 mg-day, 10 to 150 mg/day, 50 to 100 mg/day, 75 to 150
mg/day, or 150 to 300 mg/day. In various embodiments, the amount of
oseltamivir administered according to the present invention, if
present, may be at least about 1, 2, 5, 10, 15, 20, 25, 30, 40, 50,
60, 70, 75, 80, 90, 100, 110, 120, 130, 140 or 150 mg per dosage
form and up to about 75, 80, 90, 100, 110, 120, 130, 140, 150, 160,
170, 180, 190 or 200 mg per dosage form. One, two, three or four of
said dosage forms may be administered one or two times per day for
prophylaxis or treatment. The resulting daily doses may be at least
1, 2, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 75, 80, 90, 100, 110,
120, 130, 140 or 150 mg per day and up to about 75, 100, 120, 140,
150, 160, 180, 200, 220, 240, 250, 260, 280 or 300 mg per day. In
one exemplary treatment, the patient self-administers a 75 mg
dosage form BID for a total of about 150 mg per day; for
prophylaxis the dose is 75 mg taken once every 24 hours (QD).
[0085] In addition to the triple antiviral therapy, the patient may
be given an adjunctive therapy to boost natural antiviral
responses. Exemplary adjunctive therapies include treatment with
interferon, pegylated interferon, vitamin D (see e.g. Cannell et
al., Epidemiol Infect. (2006) 134:1129-40), geranylgeranylacetone
(see e.g. Unoshima et al., Antimicrob Agents Chemother. (2003)
47:2914-21), poly ICLC (see e.g. Wong et al., Antimicrob Agents
Chemother. (1995) 39:2574-6), Ampligen.RTM., and
CpG-oligodeoxynucleotides (see e.g. Lopez et al., Vet Immunol
Immunopathol. 2006 Nov. 15; 114(1-2):103-10). Such adjunctive
therapies may be particularly beneficial for prophylaxis of
influenza. However, for treatment of active influenza infections it
may be desired to avoid certain adjunctive therapies (e.g.
interferon treatment). Instead, the antiviral agents may be
administered in conjunction with anti-immune/anti-inflammatory
treatments such as corticosteroids (e.g. methylprednisolone,
hydrocortisone, etc.) or statins (e.g. atorvastatin, simvastatin,
etc.) to reduce the likelihood of a "cytokine storm".
[0086] Another aspect of the invention is a composition and use
thereof for the treatment or prophylaxis of influenza in a human
patient. In various embodiments, the compositions are prepared for
oral, parenteral, or gastric administration (e.g. via feeding
tubes) as liquids, syrups, suspensions, tablets, capsules, beads in
capsules, or beads in sachets.
[0087] In a specific embodiment, the composition comprises
amantadine or rimantadine, and ribavirin or viramidine, and
optionally oseltamivir in single dosage forms for oral, gastric, or
parenteral administration. In a specific embodiment, a single
dosage form contains amantadine in any one of the above-specified
amounts (i.e. 25, 50, 75 . . . 300 mg) in combination with
ribavirin in any one of the above-specified amounts (i.e. 25, 50,
75 . . . 500 mg) and optionally oseltamivir in any one of the
above-specified amounts (i.e. 25, 30, 40 . . . 200 mg). In one
embodiment, the composition comprises a combination of ribavirin
and ER amantadine that preferably has an in vitro dissolution
profile and/or Tmax as previously described above.
[0088] In one embodiment, the composition comprises 10 to 60 weight
percent (wt. %), 25 to 50 wt. %, or 50 to 75 wt. % amantadine or
rimantadine; and 30 to 80 wt. %, 50 to 75 wt. %, or 25 to 50 wt. %
ribavirin or viramidine, wherein the weight percents are based on
the total weight of active agents in the composition. The
composition may further comprise 0.5-30 wt. % oseltamivir. In
preferred embodiments, the composition contains amounts of
amantadine and ribavirin that exhibit additive or synergistic
effect, as described above, when used in triple combination with a
neuraminidase inhibitor such as oseltamivir, peramivir, or
zanamivir, for the treatment or prophylaxis of influenza.
[0089] For parenteral administration, the composition may be in a
lyophilized powder or sterile liquid form contained in a vial. The
vial may be fitted with a rubber septum to allow syringe entry for
reconstitution or withdrawal of the vial contents.
[0090] For oral administration, the composition may be in a unit
dosage form such as a capsule or tablet. One exemplary unit dosage
form for oral administration comprises 25-125 mg or 150-300 mg
amantadine, optionally in ER form, and 50-200 mg ribavirin in
tablets or capsules. One dosage form of the invention comprises 160
mg ER amantadine HCL and 120 mg IR ribavirin. Another exemplary
dosage form is a capsule comprising 160 mg amantadine and 160 mg
ribavirin, and 75 mg oseltamivir.
[0091] Another aspect of the invention is kits comprising an M2
inhibitor (e.g. amantadine or rimantadine), antiviral nucleoside
analogue (e.g. ribavirin or viramidine) and optionally a
neuraminidase inhibitor (e.g. peramivir, zanamivir, or
oseltamivir). The antiviral agents in the kit may be provided in
separate dosage forms that are co-packaged together, as this can
maximize the ease with which the appropriate therapeutic amount may
be administered to a subject in need thereof.
[0092] In a specific embodiment, kits comprise sachets containing
one or more of the active agents. The sachets may contain beads of
the active agents in a unit dose quantity suitable for oral,
enteral or gastric administration (e.g., via a G-, NG-, or
J-tube).
[0093] When provided as a kit for oral administration, the
antiviral agents may be provided in a blister pack. The individual
blisters may contain one antiviral agent, or two, or all three.
When provided as a blister pack, it is preferred that the antiviral
agents to be provided at each dosing interval are identified
separately--this may be accomplished by providing all of the dosage
forms for each dose within a single blister or, if packaged in
separate blisters, the blisters containing the dosage forms for
each dose may be grouped or identified as a group, e.g., by the
printing surrounding the blisters. Typically, the kit includes
instructions for use. In some embodiments, the kit may include one
or more containers of an M2 inhibitor (e.g. amantadine) and
antiviral nucleoside analogue (e.g. ribavirin) in a first package,
and the neuraminidase inhibitor in a second separate package. For
example, the kit may comprise amantadine and ribavirin co-packaged
in a first blister pack, and 75 mg oseltamivir capsules in a second
blister pack. Such kits can be prepared by co-packaging blister
packs of TAMIFLU.RTM. with blister packs comprising ribavirin and
amantadine. In another kit of the invention, a bulk supply of
TAMIFLU.RTM. (e.g. a government stockpile) is used as a source of
oseltamivir. The contents of the TAMIFLU.RTM. capsules are emptied,
optionally re-tested for shelf-life stability, then re-encapsulated
in amounts less than 75 mg/capsule (e.g. 10, 25, 35, 50 mg), and
co-packaged with additive or synergistic amounts of ribavirin and
amantadine. Extending the shelf-life of oseltamivir and reducing
the daily dose needed for treatment or prophylaxis of influenza has
the benefit of greatly extending government stockpiles of antiviral
treatment for pandemic flu.
[0094] In one embodiment, a kit comprises amantadine and ribavirin
provided as a plurality of separate oral dosage forms, with each
amantadine dosage form comprising 75-250 mg amantadine and each
ribavirin dosage form comprising 50-400 mg ribavirin. In a specific
embodiment, a kit may comprise one or more blister packs comprising
one or more dosage forms comprising 125 mg amantadine hydrochloride
in an extended release dosage form and one or more dosage forms
comprising 200 mg ribavirin. The blisters in the pack may be
arranged or marked so that one of each type of dosage form should
be administered once or twice per day. Alternatively, the dosage
forms in the blisters may be arranged to indicate that one of the
amantadine dosage forms should be administered twice per day and
one of the ribavirin dosage forms should be administered once per
day, or the dosage forms in the blisters may be arranged to
indicate that two of the amantadine dosage forms and one of the
ribavirin dosage forms should be administered once per day.
Optionally, the blister pack may be configured to include one or
more dosage forms comprising 75 mg oseltamivir similarly configured
or marked to be administered once or twice per day. FIGS. 1 and 2
of the accompanying drawings illustrate representative
configurations. Alternatively, the kit may be formatted to optimize
its convenient use adjunctively with a commercially available
neuraminidase inhibitor (e.g. TAMIFLU.RTM.).
[0095] In another embodiment, a kit may be provided comprising one
or more blister packs, wherein each blister pack comprises one or
more groups of blisters and within each group of blisters one of
the blisters contains one or two tablet or capsule dosage forms
comprising 60 to 300 mg amantadine in an extended release
formulation and one of the blisters contains one or two tablet or
capsule dosage forms comprising 25 to 200 mg ribavirin. The number
of groups within a blister pack or the number of groups provided in
the kit may vary from one to about 5, 7, 10, 14, 15, 20, 21, 28,
30, 40, 42 or 60. Optionally, said kit includes instructions for
once or twice per day administration.
[0096] Another exemplary kit for oral administration of amantadine
together with ribavirin comprises unit dosage forms of 80 mg, 180
mg, or 330 mg amantadine in immediate release or extended release
form; and unit dosage forms of 330 mg or 660 mg ribavirin. In an
exemplary treatment a patient is administered 660 to 2400 mg RBV
and 360 to 660 mg amantadine as the first dose (e.g. Day 1 AM);
thereafter (e.g. Day 2 AM to Day 10) the patient is administered
660 to 1320 mg RBV and 180 to 660 mg amantadine once daily
(QD).
[0097] When provided as a kit for parenteral treatment two or more
of the antiviral agents of the combination are provided in a form
suitable for parenteral administration. For example, the antiviral
agents may be individually formulated or co-formulated and filled
into suitable containers such as syringes, ampoules, or vials. The
active agents may be provided in the form of a lyophilized
composition in a container, and reconstituted with a
pharmaceutically acceptable carrier prior to parenteral
administration. In other embodiments, the active agents may be
provided in a liquid form in a container that may be administered
without dilution (e.g. for i.v. or i.m. bolus administration), or
alternatively added to an i.v. infusion bag. In some embodiments,
one of the antiviral agents may be provided in lyophilized form,
which, prior to administration to a patient, is reconstituted with
a liquid form of another antiviral agent provided in the kit. In
some embodiments, an M2 inhibitor (e.g. amantadine or rimantadine),
antiviral nucleoside analogue (e.g. ribavirin or viramidine), and
neuraminidase inhibitor (e.g. oseltamivir, zanamivir, or
peramivir), if present, are each in a separate container, and
thereafter the active agents are combined with a pharmaceutically
acceptable carrier prior to parenteral administration. Each
container may contain a unit dose of the active agent(s), and each
kit may have a sufficient number of the containers to treat an
individual patient for at least 12, 24, 48, or 72 hours. The kit
may have a distinctly marked container for a loading dose of one or
more of the active agents with instructions indicating that the
distinctly marked container is the first one used when initiating a
patient's treatment. Alternatively, loading doses may be separately
packaged and may have separate instructions for use. Exemplary kits
for oral treatment are further detailed in Examples 5-9 below.
Exemplary kits for parenteral administration are described in
Example 11 below.
Example 1A
A Dose Response Study of the Antiviral Activity of Amantadine,
Oseltamivir, and Ribavirin, Singly and in Double and Triple
Combinations, in A/Albany/1/98 (H3N2) Infected MDCK Cells Cultured
in Flasks
[0098] We performed experiments designed to evaluate the dose
response antiviral activity of a combination of amantadine,
oseltamivir, and ribavirin in the inhibition of A/Albany/1/98
(H3N2) viral replication. The objectives of the experiment were to
demonstrate a reduction of viral load compared to no drug and
synergistic effect of double and triple combinations compared to
monotherapy.
[0099] The EC.sub.25, EC.sub.50, and EC.sub.75 (where, e.g.,
EC.sub.50, is the concentration of drug that reduces 50% of the
virus at 72 hrs) for each drug were demonstrated in dose ranging
studies using each drug as monotherapy. Briefly, compounds at
varying doses were added to MDCK cells grown in flasks using
previously described methods (Smee et al., Chemotherapy (2002)
48:88-93). Thirty minutes after the addition of the drug, viruses
were added at a multiplicity of infection of 0.001 PFU per cell to
each well. After .about.24-78 hours, the extracellular virus medium
from each well was removed, centrifuged at 3,200 g for 5 min, and
titrated for virus. The results are provided in Table 1A.
TABLE-US-00001 TABLE 1A Inhibition Target Drug level Ire vitro C
serum C Amantadine EC25 0.054 .mu.g/ml 0.288 .mu.m Amantadine EC50
0.091 .mu.g/m1 0.480 .mu.m Amantadine EC75 0.153 .mu.g/ml 0.815
.mu.m Oseltamivir EC25 0.025 ng/ml 0.080 nM Oseltamivir EC50 0.050
ng/ml 0.160 nM Oseltamivir EC75 0.075 ng/ml 0.240 nM Ribavirin EC25
0.310 .mu.g/ml 0.760 .mu.M Ribavirin EC50 0.420 .mu.g ml 1.030
.mu.M Ribavirin EC75 0.615 .mu.g/m1 1.500 .mu.M
[0100] The EC.sub.25, EC.sub.50, and EC.sub.73 concentrations for
each drug were tested singly and at all possible double and triple
combinations for additive and/or synergistic effects on viral
replication in tissue culture, for a total of 64 conditions tested
(i.e. no drug, 9 single treatments, 27 double combination
treatments, and 27 triple combination treatments). Briefly, MDCK
cells were grown as monolayers in flasks, the drugs were added to
the culture, and the cells were infected through the introduction
of A/Albany virus at a multiplicity of infection (MOD, i.e. ratio
of infectious virus particles to the number of cells being
infected, of 0.001 PFU per cell. Culture was maintained for
.about.48 hours or until cytopathic effect was evident in
monolayer. After centrifugation, supernatants were stored at
-70.degree. C. as 3.times.500 .mu.l aliquots for TCID.sub.50, PFU,
and NA analysis and 1.times.200 .mu.l for QPCR.
[0101] Drug combinations were determined to be synergistic if the
actual inhibition of viral replication was greater than the
calculated inhibition using the MacSynergy II software as described
by Prichard et al. (Antimicrob Agents Chemother (1993) 37:540-545).
Strong synergy was seen with double combinations of amantadine with
ribavirin and amantadine with oseltamivir, at sufficiently low
concentrations that will result in fewer adverse side-effects in
humans. In addition, triple combinations with amantadine at
EC.sub.25 and EC.sub.50 demonstrated a strong synergistic effect at
concentrations that would minimize or avoid side-effects.
Example 1B
A Dose Response Study of the Antiviral Activity of Amantadine,
Oseltamivir and Ribavirin in Combination in A/Sydney/05/97 H3N2
Infected MDCK Cells
[0102] The objective of this study was to demonstrate that the
triple combination of amantadine, oseltamivir and ribavirin reduces
viral load compared to no drug, and exhibits a synergistic effect
compared to monotherapy. The methods used were the same as those
used in Example 1A, except for where noted below.
[0103] MDCK cells were grown as monolayers in 96-well plates and
infected through the introduction of A/Sydney/05/97 H3N2 virus at
MOI of 0.01 PFU per cell. Drugs were added at each of the 216
possible combinations at the following concentrations: amantadine
at 0, 0.032, 0.1, 0.32, 1.0, and 3.2 .mu.g/ml; oseltamivir at 0,
0.001, 0.0032, 0.01, 0.032, and 0.1 .mu.g/ml; and ribavirin at 0,
0.032, 0.1, 0.32, 1.0, and 3.2 .mu.g/ml.
[0104] The three-dimensional analytical method described by
Prichard and Shipman (1990), supra, and Prichard et al. (1993),
supra was used to visualize the data as depicted in FIG. 5, above.
Amantadine in double combination with ribavirin or oseltamivir
demonstrated synergy, whereas the double combination of oseltamivir
with ribavirin was not synergistic. Synergy was seen at the
following concentration ranges: amantadine at 0.1-1 .mu.g/ml,
ribavirin at 0.032-1.0 ms/ml, and oseltamivir at 0.001-0.032
.mu.g/ml. These concentrations correspond to human daily dosages of
approximately 50-200 mg amantadine, 200-600 mg ribavirin, and
2.5-25 mg oseltamivir. Synergy was not demonstrated in amantadine
concentrations above 1 .mu.g/ml due to the limit of the detection
assay (i.e. there was complete inhibition of viral load).
[0105] The experiment further demonstrated the synergistic
interactions of the three drugs when used in combination.
Sensitivity of the virus to each drug when used in triple
combination was improved by 10- to over 100-fold compared to each
drug used as monotherapy. For example, monotherapy with amantadine
at a concentration of 1 .mu.g/ml resulted in approximately a 60%
reduction in viral load, whereas approximately the same reduction
in viral load was achieved with amantadine at 0.1 .mu.g/ml in
combination with 0.01 .mu.g/ml oseltamivir and 0.32 .mu.g/ml
ribavirin, demonstrating a 10-fold increase in sensitivity to
amantadine. Monotherapy with oseltamivir at a concentration of 0.1
.mu.g/ml resulted in approximately a 50% reduction in viral load,
whereas oseltamivir at 0.001 .mu.g/ml in combination with 0.32
.mu.g/ml amantadine and 0.32 .mu.g/ml ribavirin resulted in
approximately a 65% reduction in viral load, demonstrating more
than a 100-fold increase in sensitivity to oseltamivir. Monotherapy
with ribavirin at concentrations of 1 .mu.g/ml and 3.2 .mu.g/ml
resulted in approximately 10% and 95% reductions in viral load,
respectively, whereas ribavirin at 0.032 .mu.g/ml in combination
with 0.32 .mu.g/ml amantadine and 0.01 .mu.g/ml oseltamivir
resulted in approximately a 95% reduction in viral load,
demonstrating a 100-fold increase in sensitivity to ribavirin.
Example 1C
Study to Determine the Efficacy of Mono and Combination Therapy in
an In Vitro Kinetic Assay
[0106] The objective of this study was to assess the antiviral
efficacy of amantadine, oseltamivir, and ribavirin as single agents
and in combination in an in vitro kinetic model of Influenza
A/Victoria/3/75 (H3N2) virus infection. Efficacy was assessed by
reduction in viral load, as measured by CCID50 and qPCR, and
inhibition of viral cytopathic effect (CPE), as determined by
visual inspection. A secondary objective was to determine the
optimal infectious dose and the appropriate dosing ranges for each
drug as single agents and the combination.
[0107] Treatment groups are outlined in Table 1C. Each group was
tested in duplicate, and in both MDCK and SIAT-1 cell lines.
TABLE-US-00002 TABLE 1C Study Design Amantadine Oseltamivir
Ribavirin Group.sup.a Treatment (.mu.g/mL) (.mu.g/mL) (.mu./mL)
Single-Agent Treatment Groups 1 Placebo -- -- -- 2 Amantadine
(0.15) 0.15 3 Amantadine (0.5) 0.5 4 Amantadine (1.5) 1.5 5
Oseltamivir (0.0001) 0.0001 6 Oseltamivir (0.001) 0.001 7
Oseltamivir (0.01) 0.01 8 Ribavirin (0.6) 0.6 9 Ribavirin (2.0) 2.0
10 Ribavirin (6.0) 6.0 Combination Treatment Groups 11 Combo 0.15
0.0001 0.6 (0.15/0.0001/0.6) 12 Combo (0.5/0.001/2.0) 0.5 0.001 2.0
13 Combo (1.5/0.01/6.0) 1.5 0.01 6.0 .sup.aEach group was tested in
duplicate, and in both MDCK and SIAT-1 cell lines.
[0108] MDCK and SIAT-1 cells were seeded into T25 flasks at a cell
density of 4.times.10.sup.5 cells/mL, in a total of 5 mL, in growth
media. Cells were allowed to adhere to the flasks overnight, and
the next day the flasks were inspected to verify that cells were
.about.70% confluent. Cells were washed once with 5 mL infection
media with or without drugs.
[0109] At T=0, flasks were infected with A/Influenza/3/75 (H3N2),
at an infectious dose of .about.10.sup.1 CCID50/ml. After 2 hours,
the media was removed and the cells were washed once with 5 mL
infection media with drug. The wash media were discarded and 5 mL
of fresh infection media with drug was added.
[0110] At 24 hours, the flasks were removed from the incubator and
were visually inspected for CPE. CPE, an indication of cell
viability, was qualitatively assessed by scoring the flasks on a
scale of 0 to 4, with 4 being the maximum CPE. Scoring is an
estimation of % viability. A flask that is 100% dead is scored a 4.
A flask that is 75% dead is scored at 3, 50%=2, 25%=1, and 0%=0.
The media was then completely removed from the flasks and an
aliquot was taken and frozen for subsequent viral load quantitation
by CCID50 analysis. The cell monolayer was washed twice with 5 mL
infection media with or without drugs, and 5 mL of fresh infection
media with or without drug was added. The flasks were then returned
to the incubator. At T=48, 72, 96, 120, 144, and 168 hours, the
procedure was repeated. CPE assessment was performed and samples
for viral load quantitation were collected for each regimen at each
time point.
[0111] After the last time point, all the viral load samples were
thawed and the viral load for each time point was determined by
CCID50 analysis. MDCK cells were seeded in 384-well plates at
4.times.10.sup.5 cells per ml with a volume of 50 mcL per well.
Cells were allowed to adhere overnight. 50 .mu.l of serially
diluted virus was then added to the plate, and the plates were
returned to the incubator. Plates were removed from the incubator
on Days 3 and 6 and visually scored for CPE. After 6 days, the
plates were frozen at -80 C in preparation for sanger
sequencing.
[0112] CCID50, defined as the dose at which 50% of wells are
infected, is calculated using the Karber calculation (Karber,
1931), given by the equation: log CCID50=L-d(S-0.5), where: L=log
of the lowest dilution used in the test; d=difference between log
dilution steps; and S=sum of proportion of "positive" tests (i.e.
cultures showing CPE)
[0113] In the absence of drugs, the placebo arms produced a peak
viral titer at 48 hours post infection in both the SIAT-1 and MDCK
cell lines. Peak viral titers were similar for both SIAT-1 and MDCK
cell lines, with the SIAT-1 cells producing 6.75 log.sub.10
CCID50/0.05 mL in a 24 hour period measured at 48 hours post
infection, and the MDCK cells producing 6.25 log.sub.10)
CCID50/0.05 mL. The virus appeared to replicate faster in SIAT than
MDCK cells; at 24 hours post infection, the viral titer was 4
log.sub.10 CCID50/0.05 mL for SLAT and 2.25 log.sub.10) CCID50/0.05
mL for MDCK cells. After reaching the peak, virus production
dropped in both cell lines. Presumably, the drop in viral titer is
due to all the cells having been infected and killed by the
infection.
[0114] There was a good correlation between viral load and cell
viability, with all the cells dying concurrent with the peak viral
titer or shortly thereafter. For instance, for SIAT cells the peak
viral load for the placebo group occurred at 48 hours, and complete
cell death (0% cell viability) occurred at 48 hours; for MDCK cells
the peak viral load occurred at 48 hours, and complete cell death
occurred at 72 hours.
[0115] Treatment with the drugs as single agents gave a
dose-dependent inhibition of viral load at 24 hours in both SIAT
and MDCK cells. At the 24 hour time point, each drug as single
agent at the high dose reduced viral load by 3-4 logs compared to
the placebo group in SIAT cells and by 2 logs in MDCK cells. For
all three drugs as single agents, the inhibition seen at the 24
hour time point was not sustained, and high viral titer can be
detected at later time points. Thus, none of the single agent
treatment regimens succeeded in fully inhibiting virus replication,
although in all cases single agent treatment delayed the peak of
viral production by 24 to 48 hours compared to placebo.
[0116] Cell viability data for the single agent regimens were
consistent with the viral load data: single agent treatment was
able to delay but not inhibit cell mortality. In SIAT cells, all
single agent groups had complete cell mortality at 72 hours, with
the high dose of each drug delaying cell death by 24 hours as
compared to placebo. In MDCK cells, single agent treatment delaying
cell death by a maximum of 48 to 72 hours compared to placebo. In
terms of cell viability, the best single agent regimen was the 0.5
l, .mu.g/mL dose of amantadine, where substantial cell death was
not seen until 144 hours post infection.
[0117] Combination regimens also showed a dose dependence
inhibition of virus replication. In SIAT cells, the low dose
combination group delayed peak virus production by 24 hours
compared to placebo, and the mid dose combination group delayed
peak virus production by 48 hours. In both groups, virus production
reached relatively high titers of 6.1 and 4.9 log.sub.10
CCID50/0.05 mL for the low and mid dose, respectively, albeit the
viral load as a function of time was synergistically reduced
greater than 2-fold at all times measured. The high dose
combination group, however, completely inhibited virus production
to undetectable levels up to the last time point taken at 168 hours
post infection. Consistent with the complete inhibition of virus
production, cells in the high dose combination group were also
completely protected from cell death up to the last time point
measured at 168 hours post infection. Given the fact that both SIAT
and MDCK cells were 100% viable under this regimen throughout the
entire course of the study, it can be concluded that the
combination of all three drugs at the high dose tested was not
cytotoxic, and that inhibition of virus production was due to the
synergistic antiviral effects of the drugs in the combination and
not an artificial consequence of cytotoxicity. The low and mid
combination doses delayed cell death by 24 and 96 hours in SIAT
cells, respectively, and by 72 and 96 hours in MDCK cells,
respectively. Moreover, at these low viral replication rates, the
triple combination completely suppresses the formation of
resistance.
[0118] Hence, triple combinations can lead to a synergistic
reduction in the rate of influenza viral growth and resistance.
More specifically, in using an M2 inhibitor (e.g., amantadine), a
neuraminidase inhibitor (e.g, oseltamivir, zanamivir) and a
replication inhibitor (e.g., ribavirin), there is a greater than
2-fold synergistic reduction in growth rate over the concentration
ranges of amantadine at 0.15-1.5 .mu.g/ml oseltamivir at
0.0001-0.01 .mu.g/ml, and ribavirin at 0.6-6 .mu.g/ml.
Example 2
Effect of Triple Combinations of Amantadine, Oseltamivir, and
Ribavirin on Wild Type H3N2 Influenza in the Hollow Fiber
System
[0119] We designed this experiment to test the effect of the triple
combination of amantadine, oseltamivir, and ribavirin on virus
replication in the hollow fiber model using previously described
methods (Drusano et al., Antimicrob Agents Chemother (2002)
46:464-470). The drugs, singly and in combination, were delivered
at steady state concentrations by continuous infusion at
steady-state for 168 hours. Briefly, 10.sup.8 MDCK cells were grown
in hollow fibers and infected through the introduction of 10.sup.2
influenza virus infected cells, applied in cell culture media in a
dual reservoir hollow fiber system. A wild type A/Albany (H3N2)
strain was tested. The culture was maintained for 168 hours. At
T=24, 48, 72, 96, 120, 144, and 168 hours post-infection, samples
were removed from the hollow fiber and titrated to determine viral
titer. In the drug side of the hollow fiber, twelve independent
experiments were conducted to test the drug combinations and
concentrations shown in Table 2:
TABLE-US-00003 TABLE 2 Drug Amantadine Oseltamivir Ribavirin Arm
(.mu.g/mL) (ng/mL) (.mu.g/mL 1 0 0 0 2 0.1 3 1.0 4 1 5 10 6 0.5 7 5
8 0.1 1 0.5 9 0.1 10 5 10 1 1 0.5 11 1 10 0.5 12 1 10 5
[0120] Samples were removed from the hollow fiber at various time
points to determine the number of infectious virus. The viruses
from various time points were also sequenced by Sanger method to
determine the sequence of the NA, HA, and M2 genes. A reduction in
sequence variation with combination treatment compared to treatment
with single drugs demonstrates that triple combinations inhibit the
generation of resistant mutants to any one of the drugs.
[0121] Amantadine alone had negligible effect at low dose and a 2-3
log reduction in titer at 48 hours at high dose; oseltamivir alone
had .about.1 log reduction at both doses; and ribavirin alone had
negligible effect at low dose and .about.3 log reduction at 48
hours at high dose. The combination of all three drugs at low doses
resulted in .about.8 log reduction in titer at 48 hours, a 4-log
synergistic reduction in viral growth. The combination of all three
drugs at high doses resulted in a synergistic and complete
inhibition (i.e. >8 logs) at all time points. The triple
combination thus demonstrated synergism at the following
concentrations: amantadine at 0.1-1 .mu.g/ml, oseltamivir at
0.001-0.01 .mu.g/ml, and ribavirin at 0.5-5 .mu.g/ml. These
concentrations correspond to human daily dosages of approximately
50-700 mg amantadine, 200-2500 mg ribavirin, and 2.5-10 mg
oseltamivir.
[0122] In addition, the monotherapy arms for amantadine and
oseltamivir resulted in appreciable formation of M2 and NA drug
resistance, whereas the triple high dose arm did not.
Example 3A
Effect of Triple Combinations of Amantadine, Oseltamivir, and
Ribavirin on Treatment of Influenza in Mice
[0123] We designed this experiment to determine the effects of the
triple combination of amantadine, oseltamivir, and ribavirin in a
mouse model of influenza infection.
[0124] Female mice (17-18 g) were anesthetized with ketamine (100
mg/kg) by intraperitoneal (i.p.) injection. Alzet osmotic pumps
containing amantadine were inserted surgically by subcutaneous
route in the backs of mice approximately 12 hours prior to virus
challenge. At the time of infection, mice were again anesthetized
with ketamine. They were infected intranasally (i.n.) with
approximately 2.times.10.sup.4 cell culture infectious doses
(CCID.sub.50) of A/Victoria/3/75 (H3N2) virus per mouse in a
90-.mu.l inoculum volume. The first oral treatments (by gavage)
with oseltamivir and ribavirin were given shortly before infection
and then continued once a day for 7 consecutive days (at 12 hour
intervals). There were 20 placebo-treated animals that received
water by oral gavage and initially 12 mice per drug-treated group.
The mice were held 21 days to observe for death, and were weighed
as a group every other day.
[0125] Amantadine was administered by Alzet Pump at 3 mg/ml or 10
mg/ml, to deliver 4 mg/kg/day or 13 mg/kg/day, respectively;
oseltamivir was administered at 30 mg/kg/day or 10 mg/kg/day by
oral gavage; and ribavirin was administered at 7 mg/kg/day or 21
mg/kg/day by oral gavage. The drugs were administered as
monotherapy and in the six possible triple combinations.
[0126] All monotherapy treatments were highly effective against the
infection in preventing death except for amantadine at 3 mg/ml and
ribavirin at 7 mg/kg/day. The times to death were significantly
increased at these doses, and the 27% survival rate (3 survivors
out of 11) with 3 mg/ml of amantadine was significantly different
from the placebo control.
[0127] All combinations therapies prevented mortality by 90-100%.
This was not unexpected, based upon the fact that the oseltamivir
monotherapy by itself provided a survival benefit of 92-100% at 10
and 30 mg/kg/day, and oseltamivir at these effective doses was a
component of all of the combinations. The 10 mg/ml dose of
amantadine was likewise 92% protective, so combinations with this
agent would likewise be highly protective.
[0128] Amantadine at 3 mg/ml and ribavirin at 7 mg/kg/day had
enough of the mice die in these groups to show delays in death that
differed from the placebo control. The other dose(s) of each
compound were highly protective. The compounds used in combination
showed death patterns similar to the two doses of oseltamivir or
the 10 mg/ml dose of amantadine.
[0129] The fact that all triple combination regimens were equal to
or better than all of the monotherapy regimens suggests that the
three drugs were not antagonistic in combination at the doses
tested. If there were significant antagonism between any of the
three drugs, it is expected that the triple combination would yield
lower efficacy than monotherapy.
[0130] Overall, the survival data was not useful in assessing the
benefit achieved by using the drugs in combination. However, body
weight data proved to be useful in assessing benefit of the
compounds in combination. The infection caused severe drops in body
weight in the placebo group. Weight loss during the infection was
minimal in the 10 mg/ml amantadine group, but weight loss was more
substantial in the other five monotherapy groups (i.e. amantadine
at 3 mg/ml, oseltamivir at 10 or 30 mg/kg/day, and ribavirin at 7
or 21 mg/kg/day). Using the UK/EU mortality criteria for animal
studies (death=20% weight loss), we found that 10 mg/kg/day
oseltamivir protected 40% of the mice, amantadine at 3 mg/ml
protected 10%, and ribavirin at 7 mg/kg/day protected 0%. When used
as a triple combination at the same drug concentrations, 100% of
the mice were protected. Because amantadine at 10 mg/ml was highly
protective as a monotherapy; there was not a great deal of
difference in weight between the monotherapy compared to the
combinations, but there was still a difference that favored the
combination as being superior. Resistance formation in the triple
arms was much less than recorded in the monotherapy arms (0 vs.
2%).
[0131] These results demonstrated that the triple combination
containing amantadine, oseltamivir, and ribavirin was effective in
providing both efficacy and resistance benefit to mice infected
with an influenza A (H3N2) virus.
Example 3B
Effect of Triple Combinations of Amantadine, Oseltamivir, and
Ribavirin on Treatment of Influenza in Mice
[0132] The above experiment was repeated except that initiation of
treatment did not begin until 24 or 48 hours after the mice were
infected with the virus, and the following drug concentrations were
used: amantadine at 28 mg/kg/day, oseltamivir at 10 mg/kg/day, and
ribavirin at 40 mg/kg/day.
[0133] In the study where treatment was initiated 24 hours after
infection, by day 9 post infection both the amantadine monotherapy
and the oseltamivir monotherapy groups had 100% mortality (using
the UK/EU mortality criteria); the ribavirin monotherapy group had
20% survival; and the triple combination therapy group had 90%
survival.
[0134] In the study where treatment was initiated 48 hours after
infection, by day 9 all groups had more than 20% weight loss.
However, the triple combination therapy group had the least amount
of weight loss at approximately 22%; the ribavirin monotherapy
group had about 26% weight loss; and the amantadine monotherapy and
oseltamivir monotherapy groups had nearly 35% weight loss each. By
day 13, all treatment groups had started gaining weight, but the
weight gain in the triple combination therapy group was
significantly higher--the animals in this group were approximately
90% of their original weight. In comparison, the animals in the
ribavirin monotherapy group were approximately 80% of their
original weight, and the animals in the oseltamivir monotherapy and
amantadine monotherapy groups fared no better than the untreated
controls (approximately 65-70% of their original weight).
Example 4
A Dose Response Study of the Antiviral Activity of Amantadine,
Oseltamivir and Ribavirin in Combination in H5N1 Infected MDCK
Cells Cultured in Flasks
[0135] We designed this experiment to evaluate the dose response
antiviral activity of a combination of amantadine, oseltamivir, and
ribavirin in the inhibition of A/Indonesia/05/2005 (H5N1) and
A/Vietnam/1204/2004 (H5N1) viral replication and the generation of
drug resistant mutants. The objectives of the experiment are to
demonstrate a reduction of viral load compared to no drug and
synergistic effect of combination compared to monotherapy.
[0136] MDCK cells are grown as monolayers in 96-well plates. At
T=0, 150 .mu.L of virus at 20 TCID50/mL is added to cells. Shortly
thereafter, 50 .mu.L of drug, either alone or in combination, is
added to the wells to give the indicated final concentrations. The
drugs are tested at the following concentrations in monotherapy:
amantadine at 0.00032, 0.001, 0.0032, 0.01, 0.032, 0.1, 0.32, 1,
3.2, 10, 32 and 100 .mu.g/ml; oseltamivir at 0.0001, 0.00032,
0.001, 0.0032, 0.01, 0.032, 0.1, and 0.32, 1.0, 3.2, 10, 32
.mu.g/ml; and ribavirin at 0.00032, 0.001, 0.0032, 0.01, 0.032,
0.1, 0.32, 1, 3.2, 10, 32 and 100 .mu.g/ml pg/ml. Six doses of each
drug are tested in the combination: amantadine at 0, 0.01, 0.032,
0.1, 0.32, and 1.0 .mu.g/ml; oseltamivir at 0, 0.00032, 0.001,
0.0032, 0.01, 0.032 .mu.g/ml; and ribavirin at 0, 0.032, 0.1, 0.32,
1, and 3.2 .mu.g/ml.
[0137] At T=72 hours, 100 .mu.L of supernatant from each well of
duplicate samples is pooled and frozen for TCID50 analysis. The
remaining cell monolayer is assayed for cell viability by MTS
staining.
Example 5
A Kit of Extended Release Amantadine Hydrochloride, Ribavirin and
Oseltamivir Phosphate
[0138] With reference to FIG. 1A, a blister pack (10) according to
the present invention is arranged to provide a plurality of rows
(12), each row (12) comprising a plurality of doses (14). In the
present example, there are two such rows (12), each row comprising
seven doses, although the number of rows or doses may be varied as
convenient.
[0139] Each dose comprises a plurality of different kinds of dosage
form, which are grouped together by type in separate blisters (20)
within each row to form sub-rows (18). A first kind of dosage form
(A) contains amantadine, a second kind (B) contains ribavirin, and
a third kind (C) contains oseltamivir. The different kinds of
dosage forms for a given dose are grouped together in this manner
to facilitate adherence to a prescribed dosing regimen. In this
example, a single dose comprises two amantadine capsules (A), two
ribavirin capsules (B) and one oseltamivir capsule (C), although
the number of dosage forms of each kind for each dose may also vary
as required. The blister pack shown in FIG. 1A is configured for
convenient BID dosing of each of the active agents over a seven day
period. The blister pack shown in FIG. 1B is the same as that shown
in FIG. 1A except that the oseltamivir is dosed QD.
[0140] The amantadine capsules (A) of this example each contain 125
mg amantadine hydrochloride in an extended release form (e.g. as
prepared according to U.S. Ser. No. 11/285,905) and are disposed in
each of the blisters (20) of the first and fourth sub-rows (18),
although each capsule may contain more or less amantadine or a
different salt form of amantadine as desired.
[0141] The ribavirin capsules (B) of this example each contain 200
mg ribavirin in an immediate release form, e.g., Ribavirin USP
Capsules (Schering) and are disposed in each of the blisters (20)
of the second and fifth sub-rows (18), although each capsule may
contain more or less ribavirin as desired.
[0142] The oseltamivir capsules (C) of this example each contain 75
mg oseltamivir, e.g., TAMIFLU.TM. (Roche Pharmaceuticals) and are
disposed in each of the blisters (20) of the third and sixth
sub-rows (18), although each capsule may contain more or less
oseltamivir as desired.
[0143] The blister pack also comprises instructions indicating a
typical adult dosage of two amantadine capsules, two ribavirin
capsules and one oseltamivir capsule twice per day. It will be
appreciated that the blister pack of this example contains dosage
forms sufficient for one week of dosing, comprising 28 capsules
containing 125 mg amantadine hydrochloride, 28 capsules containing
200 mg ribavirin and 14 capsules containing 75 mg oseltamivir
phosphate. Thus, the relative percentage of each active agent per
daily dose is 35 wt. % amantadine hydrochloride, 55 wt % ribavirin
and 10 wt. % oseltamivir phosphate.
Example 6
A Kit of Amantadine Hydrochloride, Ribavirin and Oseltamivir
Phosphate
[0144] A blister pack similar to the blister pack of Example 5 is
configured to provide two rows (12) of three sub-rows (18) of seven
blisters (20) per row. Two tablets or capsules of 100 mg amantadine
hydrochloride (A) in an immediate release form, e.g., Symmetrel.TM.
(Endo Pharmaceuticals or Novartis) are packaged in each of the
blisters (20) of the first and fourth sub-rows (18). Two capsules
of 200 mg ribavirin in an immediate release form, e.g., Ribavirin
USP Capsules (Schering) are packaged each of the blisters (20) of
the second and fifth sub-rows. One capsule of 75 mg oseltamivir,
e.g., Tamiflu.TM. (Roche Pharmaceuticals) is packaged in each of
the blisters (20) of the third and sixth sub-rows. The blister pack
also comprises instructions indicating a typical adult dosage of
two amantadine tablets or capsules, two ribavirin capsules and one
oseltamivir capsule twice per day. The blister pack contains dosage
forms sufficient for one week of dosing.
Example 7
A Kit of Extended Release Amantadine Hydrochloride and
Ribavirin
[0145] With reference to FIG. 2, a different blister pack (30)
according to the present invention comprises two rows (32), each of
two sub-rows (38) of seven blisters (40) per row to provide two
rows of seven doses (34) per row. Each dose (34) comprises two
different active agents, amantadine (A) and ribavirin (B),
contained in different respective types of dosage form. Each dosage
form type for each dose (34) is disposed in a separate blister
(40). The amantadine (A) and ribavirin (B) dosage forms for each
dose (34) are grouped together to facilitate adherence to the
dosing regimen.
[0146] In this example, each dose (34) comprises two amantadine
capsules (A) and two ribavirin capsules (B). Two capsules (A) of
125 mg amantadine hydrochloride in an extended release form
(prepared according to U.S. Ser. No. 11/285,905) are packaged in
each of the blisters (40) of the first and third sub-rows (38). Two
capsules of 200 mg ribavirin (B) in an immediate release form,
e.g., Ribavirin USP Capsules (Schering) are packaged each of the
blisters (40) of the second and fourth sub-rows (38).
[0147] The blister pack (30) also comprises instructions indicating
a typical adult dosage (34) of two amantadine extended release
capsules (A) and two ribavirin capsules (B) twice per day (BID).
The blister pack contains dosage forms sufficient for one week of
dosing. The kit may be used in conjunction with a separately
packaged neuraminidase inhibitor such as oseltamivir or zanamivir.
Optionally therefore, said instructions may include a further
instruction to co-administer one capsule of 75 mg oseltamivir,
e.g., Tamiflu.TM. (Roche Pharmaceuticals) (not shown) once or twice
per day in conjunction with the amantadine and ribavirin dosage
forms. Optionally, the oseltamivir or zanamivir is provided to the
subject separately from the kit as an additionally prescribed
medicine.
Example 8
A Kit of Extended Release Amantadine Hydrochloride, Ribavirin and
Oseltamivir
[0148] With reference to FIG. 3A, another kit for administering a
combination of amantadine chloride, ribavirin and oseltamivir
comprises a blister pack (50) which defines two rows (52) of
blisters, each row (52) comprising two sub-rows (58) of seven
blisters (60) each to define seven doses (54) per row. The rows
(52) serve to group together two different types of dosage form (D,
E) required for each dose (54). Each dose (54) comprises a
plurality of capsules of one type (D) and one capsule of another
type (E).
[0149] In the present example there are three capsules of the one
type (D) per dose, but fewer or more such capsules may be used as
required. Said capsules of the one type (D) comprise ribavirin and
amantadine hydrochloride, in which the amantadine hydrochloride is
provided in an extended release formulation, and the ribavirin is
in an immediate release formulation, the two formulations being
co-encapsulated.
[0150] The capsules of the other type (E) comprise oseltamivir and
are grouped with the amantadine-ribavirin capsules (D) to
facilitate adherence with the prescribing instructions. More than
one capsule of the other type (E) per dose (54) may be used if
desired. The blister pack (50) of this example is thus configured
for BID dosing of the active ingredients over a seven day period.
The blister pack shown in FIG. 3B is the same as that shown in FIG.
3A except that the oseltamivir is dosed QD.
Example 9
A Kit of Extended Release Amantadine Hydrochloride, Ribavirin and
Oseltamivir
[0151] A different blister pack (70) according to the present
invention is shown in FIG. 4. Said blister pack (70) defines two
rows (72) of blisters (80) in a manner similar to Examples 5-8
above. In this example however, there are no sub-rows, each row
comprising a single line of seven blisters (80), each of which
blisters accommodates a plurality of dosage forms (F) all of the
same type, such that within each blister are sufficient dosage
forms (F) to form a single dose (74). Each row (72) thus provides
seven doses (74).
[0152] Each dosage form (F) in this example comprises amantadine
hydrochloride in an extended release form, ribavirin and optionally
oseltamivir.
[0153] The blister pack (70) is thus configured for BID dosing of
each of the active agents over a seven day period. Such a kit could
be used alone, especially where the dosage form comprises
amantadine, ribavirin and oseltamivir, or in conjunction with a
separately packaged neuraminidase inhibitor, e.g., oseltamivir.
Example 10
Multiple Dose Safety Study in Flu Patients with an ER Amantadine,
ER Oseltamivir, and IR Ribavirin Combination
[0154] We designed the clinical study described in Table 4 to
determine the safety and pharmacokinetics of an extended release
combination formulation of amantadine and oseltamivir
co-administered with 1R ribavirin.
TABLE-US-00004 TABLE 4 Purpose To determine the safety and
pharmacokinetics of repeated doses of drug. Dosage: Dosing selected
is based on previous single ascending dose (SAD) study: e.g. 100 mg
amantadine SR + 75 mg oseltamivir + 400 mg ribavirin, 100 mg
amantadine SR + 75 mg oseltamivir + 600 mg ribavirin, 200 mg
amantadine SR + 75 mg oseltamivir + 400 mg ribavirin, 200 mg
amantadine SR + 75 mg oseltamivir + 600 mg ribavirin, 200 mg
amantadine SR + 150 mg oseltamivir + 600 mg ribavirin, or 200 mg
amantadine SR + 150 mg oseltamivir + 800 mg ribavirin, QD for 7
days Concurrent Amantadine IR or amantadine IR plus oseltamivir
Controls IR (both dosed as per manufacturers' labels) Route: Oral
Subject Males or females diagnosed with influenza Population:
Structure: 4 arm Study Sites: TBD Blinding: Patients blinded Method
of Random with equal number of males and females in Subject each
group and equal age distributions within groups Assignment: Total
Sample 24 Subjects 6 per dosing arm Size: Primary Efficacy None
Endpoint: Adverse Events: Monitored at least twice daily for
behavioral, cardiovascular, and gastrointestinal effects reported
for high doses of amantadine or oseltamivir (including dizziness,
headache, confusion, constipation, hypertension, coughing, nausea,
diarrhea, vomiting). Blood Collection By cannula through first day
of study period then 2-4 times daily for rest of study Analysis
Assays to measure amantadine, oseltamivir, ribavirin and
potentially other physiological parameters, adverse events
Example 11
A Phase 2 Clinical Trial of the Safety and Efficacy of Intravenous
Triple Combination Antiviral Drug Therapy for the Treatment of
Severe Avian Influenza
[0155] We designed this study to: 1) evaluate the safety and
tolerability of i.v. triple combination antiviral drug therapy
(TCAD) in the treatment of patients with severe avian influenza; 2)
to evaluate the rate and extent of antiviral efficacy of TCAD over
the course of treatment as assessed by negative reverse
transcriptase-polymerase chain reaction (RT-PCR) detection of viral
ribonucleic acid (RNA) in upper and lower respiratory tract,
gastrointestinal tract (feces), and blood (viremia), nose and
throat; and 3) assess the rate and extent of antiviral drug
resistance to TCAD over the course of treatment by pyrosequencing
(or equivalent).
[0156] Study Size: 12 patients
[0157] Inclusion Criteria: 1) age 1 year; 2) fever 38.0.degree. C.;
3) at least one respiratory symptom: cough, dyspnea (shortness of
breath), and/or sore throat; 4) illness (onset of fever,
respiratory symptoms, or constitutional symptoms) begun in the last
7 days; and 5) have evidence of epidemiologic risk for avian
influenza as defined by meeting one of the following criteria
within 14 days prior to the time of illness onset: (a) There were
dead or sick birds within the subjects village or neighborhood
(within a 2 km radius); (b) The subject had direct bird or poultry
contact (either healthy or sick birds or poultry); (c) The subject
had face-to-face contact with someone with known or suspected avian
influenza; or (d) The subject had possible laboratory exposure to
H5N1 virus.
[0158] Exclusion Criteria: 1) History of allergy or severe
intolerance (as judged by the investigator) to amantadine
hydrochloride, zanamivir, and/or ribavirin, and or to any
components of these drug products; and 2) Alternate explanation for
the patient's clinical symptoms (i.e. other than influenza) as
determined by the investigator with the information immediately
available.
[0159] Screening Criteria: 1) The following samples will be tested
by qualitative RT-PCR for H-5, however the decision to initiate
TCAD therapy is not dependent upon receipt of the results from
these tests: nasal swab.times.2; oropharyngeal (throat)
swab.times.2; nasopharygeal aspirate (NPA; as the NPA is an
obtrusive test for some subjects, the NPA can be omitted or a nasal
wash can be substituted for the NPA at the discretion of the
investigator); bronchial alveolar lavage (BAL) or endotracheal tube
aspirate; blood sample (for viremia, CBC, and serum chemistry); and
urine pregnancy for females 12 years old.
[0160] TCAD dosing regimen: The duration of treatment will be a
minimum of 5 days, but may be extended as determined by the
physician based on the benefit/risk assessment for each individual
patient. A kit for 5 days of treatment contains: 1) 10 vials
containing .about.4 ml of 100 mg/ml amantadine in water with or
without buffer, 2) 10 vials containing 15 ml of 75 mg/ml ribavirin
in water with or without buffer, and 3) 10 vials of .about.7 ml of
10 mg/ml zanamivir in water with or without buffer or, as an
alternative to zanamivir, 10 vials of lyophilized oseltamivir.
[0161] For treatment, 3.3 ml from an amantadine vial is drawn into
a syringe and injected into a 500 ml infusion bag of 0.9% or 5%
dextrose/0.45% saline producing a concentration of 0.66 mg/ml of
amantadine; the infusion volume rate is set to 40 ml/min, which
results in an infusion dose rate of 26 mg/hour (630 mg/day). 13.5
ml from a ribavirin vial is drawn into a syringe and injected into
a 500 ml infusion bag of saline producing a concentration of 2.03
mg/ml of ribavirin; the infusion volume rate is set to 40 ml/min,
which results in an infusion dose rate of 84.6 mg/hour (2030
mg/day). 6.5 ml zanamivir is drawn into a syringe and injected into
a 500 ml infusion bag of saline producing a concentration of 0.13
mg/ml of zanamivir; the infusion volume rate is set to 40 ml/min,
which results in a infusion dose rate of 5.3 mg/hour (127 mg/day).
Alternatively to the zanamivir, 5 ml of water is drawn into a
syringe and injected into a vial of lyophilized oseltamivir to
reconstitute the sterile powder producing a concentration of 46
mg/ml oseltamivir phosphate; the infusion volume rate is set to 40
ml/min, which results in an infusion dose rate of 18.4 mg/hour (442
mg/day). At these infusion rates new bags of each antiviral agent
need to be prepared every 12 hours.
[0162] Safety: Adverse events will be monitored. The NIH Division
of AIDS Table for Grading the Severity of Adult and Pediatric
Adverse Events (DAIDS AE grading table) will be used to assess the
severity of an adverse event.
[0163] Clinical Evaluations: Clinical evaluations include:
in-hospital mortality; rate and extent of clinical failure over the
course of treatment [clinical failure is defined as death, severe
tachypnea (respiratory rate.gtoreq.30 for ages.gtoreq.12 years,
rate.gtoreq.40 for ages 6 to 12 years, rate.gtoreq.45 for ages 3 to
6 years, rate.gtoreq.50 for ages 1 to 3 years); severe dyspnea
(unable to speak full sentences, or use of accessory respiratory
muscles); arterial oxygen saturation<92% on room air by
trans-cutaneous method; need for mechanical ventilation or ICU
admission]; 28-day mortality for subjects; 180-day mortality for
subjects; use of mechanical ventilation at any time for subjects;
number of admissions for subjects with avian influenza; development
of acute respiratory distress syndrome (ARDS) at any time for
subjects; duration of hospitalization for subjects; duration of
symptoms as defined by time to absence of fever, no or minimal
symptoms, no need for relief medication, and resumption of normal
activity.
[0164] Virologic Endpoints: Virologic evaluations include: rate and
extent of viral load and shedding over the course of treatment as
assessed by negative RT-PCR for viral RNA in nose and throat swabs,
blood, NAL and BAL samples; rate and extent of the emergence of
amantadine or zanamivir antiviral drug resistance as determined by
pyrosequencing; and genetic characterization of resistant
variants.
[0165] While preferred embodiments of the present invention have
been shown and described herein, it will be obvious to those
skilled in the art that such embodiments are provided by way of
example only. Numerous variations, changes, and substitutions will
now occur to those skilled in the art without departing from the
invention. It should be understood that various alternatives to the
embodiments of the invention described herein may be employed in
practicing the invention. It is intended that the following claims
define the scope of the invention and that methods and structures
within the scope of these claims and their equivalents be covered
thereby.
* * * * *