WO2010047826A2 - Dosing regimens and dosage formulations of an antiviral peptide therapeutic - Google Patents

Abstract

Provided herein are dosage formulations and dosing regimens of an antiviral peptide therapeutic, including methods of using the same.

Description

DOSING REGIMENS AND DOSAGE FORMULATIONS OF AN ANTIVIRAL PEPTIDE THERAPEUTIC

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 61/108,048, filed October 24, 2008, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] Provided herein are dosage formulations and dosing regimens of an antiviral peptide therapeutic, including methods of using the same.

BACKGROUND OF THE INVENTION

[0003] T1144 (also referred to as TRI-1144 and TR-0291144) is a synthetic 38 amino acid peptide derived from the HIV gp41 sequence useful for inhibiting viral infusion and suppressing HIV. See U.S. Patent Application Publication No. 2007- 0179278-A1 , published August 2, 2007, incorporated by reference herein in its entirety. T1144 has demonstrated similar to improved potency, a higher genetic barrier to resistance in vitro and markedly improved physical and pharmacokinetic properties in cynomolgus monkies relative to enfuvirtide (Fuzeon™), the first approved HIV entry inhibitor and an important therapeutic for treatment-experienced patients. T1144 is thought to bind to the HR1 domain of HIV-1 env gp41 , thereby blocking a key conformational change that is essential for viral fusion. [0004] For peptides to manifest their proper biological and therapeutic affect in patients, they must be present in appropriate concentrations at their sites of action in vivo. More specifically, the pharmacokinetics of any particular compound, including any particular peptide, is dependent on the bioavailability, distribution and clearance of that compound in vivo. However, the chemical nature and characteristics of peptides, such as size, complexity, conformational requirements and solubility profiles, tend to cause peptides to have pharmacokinetic profiles that are suboptimal compared to the pharmacokinetic profiles of other compounds. [0005] Accordingly, there has been considerable effort in the art to attempt to develop dosing regimens and dosage formulations to administer therapeutic agents, such as peptides, so that both the bioavailability and the half-life of the therapeutic agents are increased. In particular, a fusion inhibitor with enhanced convenience in both administration and dosing frequency, improved tolerability, an increased barrier to resistance and a robust pharmacokinetic profile would provide a significant improvement for HIV-infected patients over currently available treatment options. While progress has been made in this regard (see U.S. Patent Application No. 12/080,404, filed April 2, 2008 directed to compositions containing T1144 and a gelling material capable of forming a matrix upon solvent-subcutaneous fluid exchange), there a remains a need in the art for additional dosage formulations and dosing regimens useful for delivering peptide therapeutics with desirable pharmacokinetic profiles. The dosage formulations, dosing regimens and related methods provided herein address these needs.

SUMMARY OF THE INVENTION

[0006] In one embodiment, provided herein are dosage formulations which can, for example, be used to administer T1144 (SEQ ID NO:1) or a derivative thereof to a patient. Specifically, provided herein are dosage formulations comprising about 1 mg to about 500 mg of T1144 or a derivative thereof. Without being limited by theory, the embodiments provided herein are based, at least in part, on the unexpected discovery of desirable pharmacokinetic profiles upon administration of T1144 to a subject, which are achievable by a once daily low-volume administration. Notably, the dosage formulations and dosing regimens provided herein are believed to provide enhanced convenience in both administration and dosing frequency relative to currently available treatment options. In particular, the dosage formulations and dosing regimens provided herein are thought to allow for lower injection volumes, less frequent dosing and fewer injection-site reactions relative to currently available treatment options (e.g., enfuvirtide (Fuzeon™)). [0007] In another embodiment, the dosage formulations provided herein are stable. In a particular embodiment, the dosage formulations provided herein are stable for up to 18 months at temperature of up to about 25°C. Without being limited by theory, it is believed that T1144 is unexpectedly stable in solution in part because it self-associates to form a trimer in solution. Peptides that are not stable can lose biological activity or precipitate out of solution over time. [0008] In certain embodiments, the dosage formulations provided herein can further comprise another antiviral agent including, but not limited to, an antiviral peptide.

[0009] In another embodiment, provided herein are dosing regimens comprising daily administration of a dosage formulation comprising T1144 or a derivative thereof provided herein to a patient.

[0010] In another embodiment, provided herein are methods for achieving linear, dose-proportional desirable pharmacokinetic parameters (e.g., U₁₂, Cmax. Uax, AUC, CL/F, Vz/F and MRT) over a dosage range of about 1 mg to about 500 mg T1144 or a derivative thereof, comprising administering a dosage formulation provided herein to a patient.

[0011] In another embodiment, provided herein are methods of using the dosage formulations provided herein. In a particular embodiment, the dosage formulations are used as part of a therapeutic regimen, for example, an antiviral therapeutic regimen. In certain embodiments, such a therapeutic regimen can, for example, be used for the therapy of HIV infection, e.g., HIV-1 infection.

[0012] In another embodiment, provided herein are methods of using the dosage formulations provided herein for inhibition of the transmission of HIV to a target cell, comprising administering an amount of a dosage formulation provided herein to a patient, such that the target cell is contacted with an amount of T1144 or a derivative thereof and optionally another antiviral agent, effective to inhibit infection of the cell by the virus.

[0013] In another embodiment, provided herein are methods of treating HIV infection (in one embodiment, HIV-1 infection) comprising administering to an HIV- infected patient a dosage formulation provided herein in an amount effective to treat the HIV infection.

[0014] In another embodiment, provided herein are methods for the use of a dosage formulation containing an effective amount of T1144 or a derivative thereof, in the manufacture of a medicament for use in therapy of HIV infection (e.g., used in a method of inhibiting transmission of HIV, a method of inhibiting HIV fusion, and/or a method of treating or inhibiting HIV infection).

[0015] In another embodiment, provided herein are devices, such as auto-injector devices (e.g. a pre-filled pen device) comprising a dosage formulation provided herein. Specific Embodiments

[0016] In another embodiment, provided herein are injectable dosage formulations consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier.

[0017] In another embodiment, provided herein are methods for administering

T1144 or a derivative thereof, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient.

[0018] In another embodiment, provided herein are methods for achieving a linear and dose-proportional pharmacokinetic parameter over a dosage range of about 25 mg to about 250 mg T1144 or a derivative thereof, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient, wherein the pharmacokinetic parameter is selected from the group consisting of ti_/2, Cm_3x, t_max, AUC, CL/F, Vz/F and MRT.

[0019] In another embodiment, provided herein are methods of treating HIV infection, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient.

[0020] In another embodiment, provided herein are methods for inhibition of the transmission of HIV to a target cell in a patient, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient.

[0021] In another embodiment, provided herein are methods for the manufacture of a medicament comprising a dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier for use in therapy of HIV infection.

[0022] In another embodiment, provided herein are auto-injector devices comprising a dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier.

[0023] The above and other objects, features, and advantages of the dosage formulations and methods provided herein will be apparent in the following Detailed

Description when read in conjunction with accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a schematic of HIV-1 gp41 showing the heptad repeat 1 region

(HR1) (SEQ ID NO: 2) and heptad repeat 2 region (HR2) (SEQ ID NO: 3) , which includes the well-known leucine zipper-like motif INNYTSLI, along with other functional regions of gp41. Exemplary natural amino acid sequences corresponding to HR1 and HR2, and the amino acid position numbering, are shown for purposes of illustration and in relation to gp160, strain HIVm_B.

[0025] FIG. 2 shows a comparison of the natural amino acid sequences contained within the HR2 region of HIV-1 gp41 for purposes of illustration, and not limitation, as determined from various laboratory strains and clinical isolates, wherein illustrated are some of the variations in amino acid sequence (e.g., polymorphisms), as indicated by the single letter amino acid code (SEQ ID NOs: 4-19). For purposes of example, those isolate sequences that align with the amino acid sequence INNYTSLI in the top isolate sequence correspond to HR2 leucine zipper-like motifs.

[0026] FIG. 3 is a schematic diagram showing the synthesis of an HIV fusion inhibitor peptide, having an amino acid sequence of SEQ ID NO:1 , using a fragment condensation approach involving assembly of 3 peptide fragments.

[0027] FIG. 4 is a schematic diagram showing the synthesis of an HIV fusion inhibitor peptide, having an amino acid sequence of SEQ ID NO:1 , using a fragment condensation approach involving assembly of 2 peptide fragments.

[0028] FIG. 5 shows the pharmacokinetic parameters of a once daily administration of T1144 (25 mg and 50 mg).

[0029] FIG. 6 shows the mean log plasma concentration of a single dose of

T1144 (25 mg, 50 mg, 125 mg and 250 mg).

[0030] FIG. 7 shows the linear dose-proportional C_max of T1144.

[0031] FIG. 8 shows the in vivo comparative pharmacokinetic parameters of

T1144 and enfuvirtide.

DETAILED DESCRIPTION

Definitions

[0032] The term "patient," when used herein for purposes of the specification and claims, means a mammal, such as a human. In a particular embodiment, a "patient" is a mammal, such as a human, in need of treatment of a disease or disorder disclosed herein, such as HIV or AIDS. In another embodiment, a "patient" is an HIV-infected human who has failed one or more other HIV therapies. [0033] The term "target cell," when used herein for purposes of the specification and claims, means a cell capable of being infected by HIV. In one embodiment, the cell is a human cell(s); and in another embodiment, the cell is a human cell(s) capable of being infected by HIV via a process including membrane fusion. In another embodiment, the cell is present in a patient, such as a human patient. [0034] The term "pharmaceutically acceptable carrier," when used herein for purposes of the specification and claims, means a carrier medium that does not significantly alter the biological activity of the active ingredient (e.g., T1144 or a derivative thereof) to which it is added. A pharmaceutically acceptable carrier includes, but is not limited to, one or more of: water, buffered water, saline (e.g., phosphate buffered saline (PBS)), 0.3% glycine, aqueous alcohols, isotonic aqueous solution; and may further include one or more substances such as glycerol, oils, salts, such as sodium, potassium, magnesium and ammonium, phosphonates, carbonate esters, fatty acids, saccharides (e.g., mannitol), polysaccharides, polymers, excipients, and preservatives and/or stabilizers (to increase shelf-life or as necessary and suitable for manufacture and distribution of the composition). In one embodiment, the pharmaceutically acceptable carrier is suitable for intramuscular, subcutaneous or parenteral administration. In a specific embodiment, the pharmaceutically acceptable carrier does not include a gelling material (i.e., a solvent-miscible material that, when present in a composition comprising a solvent and a gelling material, forms a matrix upon solvent-subcutaneous fluid exchange, that is, solvent-subcutaneous patient fluid exchange).

[0035] The term "HIV" refers to Human Immunodeficiency Virus, and in one embodiment HIV-1.

[0036] The term "derivative thereof," when used herein with respect to T1144 means a compound that arises from T1144 by replacement of one or more atoms with another atom or group of atoms which preferably retains all or substantially all of the antiviral activity of T1144. Specific derivatives of T1144 include, but are not limited to, HIV fusion inhibitor peptides having the amino acid sequence of SEQ ID NO:1 , wherein the HIV fusion inhibitor peptide contains one or more chemical groups: B- TTWEAWDRAIAEYAARIEALLRALQEQQEKNEAALREL -Z

I

U wherein one or more of the amino terminal end, carboxyl terminal end, or side chain free reactive functionality (e.g., an epsilon amine of an internal lysine) is modified by a chemical group (B, U, Z; wherein B, U, and Z may be the same chemical group or different chemical groups) which may include, but is not limited to, one or more of: a reactive functionality, a chemical protecting group (CPG), a linker or a macromolecular carrier. Techniques useful for introducing a chemical group at the N-terminus of a peptide fragment, or the C-terminus of a peptide fragment, at a free amine at an internal amino acid, or a combination thereof, are well known in the art.

[0037] The term "isolated," when used in reference to T1144 or a derivative thereof means that it is substantially free of components which have not become part of the integral structure of T1144 or a derivative thereof, e.g., such as substantially free of chemical precursors or other chemicals when chemically synthesized, produced, or modified using biological, biochemical, or chemical processes. In certain embodiments, the T1144 molecule or derivative thereof is more than about 75%, 80%, 85%, 90%, 95%, 97%, 99% or 99.9% pure by weight. [0038] The term "stable," when used in reference to the dosage formulations provided herein, means that T1144 in the dosage formulation loses minimal biological activity (as measured using in vitro assays or in vivo models known to be useful in connection with the diseases, disorders or conditions referenced herein) over time. The term "stable" when used in reference to the dosage formulations provided herein, can also mean that T1144 stays in solution (i.e., does not precipitate out of solution). In certain embodiments, the dosage formulation retains about 75%, about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99% or about 99.5% of it initial biological activity. In certain embodiments, the dosage formulation is stable for about one week, about one month, about three months, about six months, about nine months, about 12 months, about 15 months, about 18 months or longer when stored at a temperature of about 2°C, about 4°C, about 6°C, about 8°C, about 10⁰C, about 12°C, about 14°C, about 16°C, about 18°C, about 20⁰C, about 22°C, about 24°C, about 25°C, about 26°C, about 28⁰C or about 30⁰C.

[0039] The term "reactive functionality," when used herein for purposes of the specification and claims, means a chemical group or chemical moiety that is capable of forming a bond with another chemical group or chemical moiety. With respect to chemical groups, a reactive functionality is known to those skilled in the art to comprise a group that includes, but is not limited to, maleimide, thiol, carboxylic acid, hydrogen, phosphoryl, acyl, hydroxyl, acetyl, hydrophobic, amine, amido, dansyl, sulfo, a succinimide, a thiol-reactive, an amine-reactive, a carboxyl-reactive, and the like. One reactive functionality can be used to the exclusion of another reactive functionality.

[0040] The term "linker," when used herein for purposes of the specification and claims, means a compound or moiety that acts as a molecular bridge to operably link two different molecules (e.g., a first reactive functionality of a linker is covalently coupled to a reactive functionality of a macromolecular carrier, and a second reactive functionality of the linker is covalently coupled to a reactive functionality of T1144). The linker can be amino acids, as in production of a recombinant fusion protein containing one or more copies of T1144. Alternatively, the two different molecules can be linked to the linker in a step-wise manner (e.g., via chemical coupling). In general, there is no particular size or content limitations for the linker so long as it can fulfill its purpose as a molecular bridge. Linkers are known to those skilled in the art to include, but are not limited to, chemical chains, chemical compounds (e.g., reagents), amino acids, and the like. The linkers can include, but are not limited to, homobifunctional linkers, heterobifunctional linkers, biostable linkers, hydrolysable linkers, and biodegradable linkers, as well as others known in the art. Heterobifunctional linkers, well known to those skilled in the art, contain one end having a first reactive functionality to specifically link a first molecule, and an opposite end having a second reactive functionality to specifically link to a second molecule. It will be evident to those skilled in the art that a variety of monofunctional, difunctional, and polyfunctional reagents (such as those described in the catalog of the Pierce Chemical Co., Rockford, III.) can be employed as a linker. Depending on such factors as the molecules to be linked, the conditions in which the linking is performed, and the intended pharmacokinetic properties upon administration, the linker can vary in length and make-up for optimizing such properties as: preservation of biological activity and function, stability, resistance to certain chemical and/or temperature parameters, susceptibility to cleavage in vivo, and of sufficient stereo-selectivity or size. [0041] The term "macromolecular carrier" when used herein for purposes of the specification and claims, means a molecule which is linked, joined, or fused (e.g., chemically, or through recombinant means using genetic expression) to T1144 or a derivative thereof, whereby the molecule is capable of conferring one or more properties of: stability to T1144 or a derivative thereof, increase in biological activity of T1144 or a derivative thereof, or an increase in plasma half-life of T1144 or a derivative thereof (e.g., prolonging the persistence of T1144 or a derivative thereof in the body) relative to that with respect to T1144 or a derivative thereof in the absence of the molecule. Such macromolecular carriers are well known in the art to include, but are not limited to, serum proteins, polymers, carbohydrates, and lipid-fatty acid conjugates. Serum proteins typically used as macromolecular carriers include, but are not limited to, transferrin, albumin (preferably human), immunoglobulins (preferably human IgG or one or more chains thereof), or hormones. Polymers typically used as macromolecular carriers include, but are not limited to, polylysines or poly(D-L-alanine)-poly(L-lysine)s, or polyols. A polyol can comprise a water- soluble poly(alkylene oxide) polymer, and can have a linear or branched chain(s). A polymer can be a branched chain polyol (such as a PEG, having multiple (for example, 3 or more) chains, each which can be coupled to T1144 or a derivative thereof directly or via a linker); and in one embodiment, a branched chain polyol that is biodegradable, and/or cleaved over time, under in vivo conditions. Suitable polyols include, but are not limited to, polyethylene glycol (PEG), polypropylene glycol (PPG), and PEG-PPG copolymers. In one embodiment, a polyol comprises PEG having an average molecular size selected from the range of from about 1 ,000 Daltons to about 20,000 Daltons. Other types of macromolecular carriers that can be used, which generally have molecular weights higher than 20,000 Daltons, are known in the art.

[0042] The term "chemical protecting group," or "CPG," when used herein for purposes of the specification and claims, means a chemical moiety that is used to block a reactive functionality comprising an amine group from chemically reacting with another reactive functionality. Chemical protecting groups are well known by those in the art of peptide synthesis to include, but are not limited to, Ac (acetyl), amide, amido, tBu (t-butyl), trt (triphenylmethyl(trityl)), OtBu (tert-butoxy), Boc or t- Boc (tert-butyloxycarbonyl), Fmoc (9-fluorenylmethoxycarbonyl), Aoc (t-amyloxy- carbonyl), TEOC (β-trimethylethyloxycarbonyl), CLIMOC (2-chloro-1-indanyl methoxyl carbonyl), BIMOC (benz-[f]-indene-3-methoxylcarbonyl), PBF (2,2,4,6,7- pentamethyldihydrobenzofuan-5-sulfonyl), 2-CI-Z (chlorobenzyl-oxycarbonyl), Alloc (allyloxycarbonyl), Cbz (benzyloxycarbonyl), Adoc (adamantyloxy-carbonyl), Mcb (1- methylcyclobutyloxycarbonyl), Bpoc (2-(p-biphenylyl) propyl-2-oxycarbonyl), Azoc (2-(p-phenylazophenyl) propyl-2-oxycarbonyl), Ddz (2,2 dimethyl-3,5- dimethyloxybenzyl-oxycarbonyl), MTf (4-methoxy-2,3,6-trimethoylbenzenesulfonyl), PMC (2,2,5,7,8-pentamethylchroman-6-sulfonyl), Tos (tosyl), Hmb (2-hydroxyl-4- methoxybenzyl), Poc (2-phenylpropyl-2-oxycarbonyl), Dde (1-(4,4-dimethyl-2,6- dioxocyclohex-1 -ylidene)ethyl), ivDde (1 -(4,4-dimethyl-2,6-dioxo-cyclohex-1 -ylidene)- 3-methylbutyl), benzyl, dansyl, para-nitrobenzyl ester, and the like. One chemical protecting group can be used to the exclusion of another chemical protecting group. [0043] The term "pharmacokinetic properties," when used herein for purposes of the specification and claims, means the total amount of T1144 or a derivative thereof in a dosage formulation that is systematically available over time. Pharmacokinetic properties can be determined by measuring total systemic concentrations of T1144 or a derivative thereof over time after being administered in vivo. As an example, pharmacokinetic properties can be expressed in terms of the Area Under the Curve (AUC), biological half-life, and/or clearance. AUC is the integrated measure of systemic T1144 or a derivative thereof concentrations over time in units of mass- time/volume. Following the administration of a dose of T1144 or a derivative thereof, the AUC from the time of dosing to the time when no active ingredient remains in the body, is a measure of the exposure of the individual to T1144 or a derivative thereof (and/or a metabolite of T1144 or a derivative thereof). A dosage formulation has "improved" or "increased" pharmacokinetic properties when the bioactive molecule(s) which it contains has one or more of: (a) a longer ("increase") in biological (terminal elimination) half life ("t ¹/4"), (b) a decreased or lower C_max. In other embodiments, a dosage formulation has "improved" or "increased" pharmacokinetic properties when the bioactive molecule(s) which it contains has a more desirable value for another pharmacokinetic property relative to a different dosage formulation or a dosage formulation containing a different bioactive molecule(s). Additional pharmacokinetic properties include: t_max (time to maximum plasma concentration), CL/f (apparent total systemic clearance (Uh), as calculated by the following equation: CL/F = (Dose/AUC_0-«,)*1000), Vz/F (Apparent steady-state volume of distribution (L), as calculated by the following equation: V_z/F = Dose/(λ_z» AUCo-O₀)) and MRT (mean residence time (h), as calculated by the following equation: MRT = AUMCo-_∞/AUCo-o_o. AUMCo-co is the area under the first moment (time*plasma TRI-1144 concentration vs. time) curve, computed using the linear trapezoidal rule for incremental trapezoids, the log-trapezoidal rule for decremental trapezoids and extrapolation to infinity using the terminal slope).

[0044] The term "effective amount," when used herein in connection with T1144 or a derivative thereof, means an amount of T1144 or a derivative thereof that will achieve the desired result of a particular method. In one embodiment, an effective amount of T1144 or a derivative thereof can be an amount that is sufficient (by itself and/or in conjunction with a regimen of doses) to reduce (e.g., relative to that in the absence of T1144 or a derivative thereof) HIV viral load in a patient. In another embodiment, an effective amount of T1144 or a derivative thereof can be an amount sufficient to inhibit (e.g., relative to that in the absence of T1144 or a derivative thereof) infection of a cell by HIV or to inhibit viral entry of a target cell. Such inhibition can be measured using assays known in the art. In another embodiment, an effective amount of T1144 or a derivative thereof can be an amount sufficient to ameliorate a symptom associated with an HIV infection. An effective amount of T1144 or a derivative thereof can be determined by one skilled in the art using data from routine in vitro and in vivo studies well know to those skilled in the art. When used in connection with a dosage formulation, the term "effective amount" means a amount of a dosage formulation that provides an effective amount of T1144 or a derivative thereof, as described above.

[0045] The terms "treatment" or "therapy," or grammatical equivalents thereof, are used interchangeably with respect to HIV infection, and for purposes of the specification and claims, mean that a composition comprising T1144 or a derivative thereof can be used to affect one or more processes associated with HIV infection, or one or more parameters or endpoints used as indicators for determining the therapeutic effect of such treatment or therapy (e.g., "therapeutic application"). For example, T1144 or a derivative thereof can be used to inhibit one or more of the following processes: transmission of HIV to a target cell; fusion between HIV and a target cell ("HIV fusion"); viral entry (the process of HIV or its genetic material entering into a target cell during the infection process); and syncytia formation (e.g., fusion between an HIV-infected cell, and a target cell). Viral suppression

(determined by methods known in the art for measuring the viral load of HIV in a body fluid or tissue) is a commonly used primary endpoint, and an increase in the number of CD4⁺ cells circulating in the bloodstream is a commonly used secondary endpoint, for assessing the efficacy of a drug in treatment or therapy of HIV infection; each being a measurable effect of inhibiting transmission of HIV to a target cell.

Thus, a dosage formulation comprising T1144 or a derivative thereof can be used to affect a therapeutic application comprising viral suppression and/or an increase in the relative number of circulating CD4⁺ cells.

Dosage Formulations

[0046] In one embodiment, provided herein are dosage formulations which can, for example, be used to administer T1144 (SEQ ID NO:1) or a derivative thereof to a patient.

[0047] In a particular embodiment, provided herein are dosage formulations comprising about 1 mg to about 500 mg of T1144 or a derivative thereof. In specific embodiments, provided herein are dosage formulations comprising about 25 mg, about 50 mg, about 125 mg, about 250 mg or about 500 mg of T1144 or a derivative thereof.

[0048] In a further embodiment, the dosage formulations comprise about 1 mg to about 500 mg of T1144 or a derivative thereof (e.g., about 25 mg, about 50 mg, about 125 mg, about 250 mg or about 500 mg of T1144 or a derivative thereof) and a pharmaceutically acceptable carrier.

[0049] In a further embodiment, the dosage formulations consist essentially of about 1 mg to about 500 mg of T1144 or a derivative thereof (e.g., about 25 mg, about 50 mg, about 125 mg, about 250 mg or about 500 mg of T1144 or a derivative thereof) and a pharmaceutically acceptable carrier.

[0050] In a specific embodiment, the pharmaceutically acceptable carrier is water, buffered water or saline. In another specific embodiment, the dosage formulation does not contain a gelling material (i.e., a solvent-miscible material that, when present in a composition comprising a solvent and a gelling material, forms a matrix upon solvent-subcutaneous fluid exchange, that is, solvent-subcutaneous patient fluid exchange).

[0051] Further provide herein are single unit dosage forms comprising about 25 mg of T1144 or a derivative thereof and about 0.2 ml_ of saline, about 50 mg of T1144 or a derivative thereof and about 0.4 ml_ of saline or about 125 mg of T1144 or a derivative thereof and about 1 ml_ of saline. Still further provide herein are single unit dosage forms consisting essentially of about 25 mg of T1144 or a derivative thereof and about 0.2 ml_ of saline, about 50 mg of T1144 or a derivative thereof and about 0.4 ml_ of saline or about 125 mg of T1144 or a derivative thereof and about 1 ml_ of saline. Without being limited by theory, it is thought that such dosage formulations allow for more convenient therapy due to lower dosing volumes than currently available treatment options. In addition, a further advantage of dosage formulations provided herein are a low incidence of injection-site reactions. [0052] Further provided herein are stable dosage formulations comprising T1144 and a pharmaceutically acceptable carrier (e.g., water, saline or PBS). Further provided herein are stable dosage formulations consisting essentially of T1144 and a pharmaceutically acceptable carrier (e.g., water, saline or PBS). In a particular embodiment, the dosage formulations provided herein are stable for up to 18 months at temperature of about 4°C to about 25°C. In one embodiment, provided herein are stable dosage formulations comprising T1144 at a concentration of about 10 mg/mL to about 200 mg/mL and a pharmaceutically acceptable carrier (e.g., water, saline or PBS). In one embodiment, provided herein are stable dosage formulations consisting essentially of T1144 at a concentration of about 10 mg/mL to about 200 mg/mL and a pharmaceutically acceptable carrier (e.g., water, saline or PBS). Specific concentrations of T1144 useful in the stable dosage formulations provided herein include about 10 mg/mL, about 25 mg/mL, about 50 mg/mL, about 75 mg/mL, about 100 mg/mL, about 125 mg/mL, about 150 mg/mL, about 175 mg/mL and about 200 mg/mL.

[0053] In certain embodiments, the dosage formulations provided herein retain about 75%, about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99% or about 99.5% of their initial biological activity. In other embodiments, the dosages formulations provided herein are stable for about one week, about one month, about three months, about six months, about nine months, about 12 months, about 15 months, about 18 months or longer when stored at a temperature of about 2⁰C, about 4°C, about 6°C, about 8°C, about 1O⁰C, about 12°C, about 14°C, about 16°C, about 18°C, about 20°C, about 22°C, about 24°C, about 25⁰C, about 26°C, about 28⁰C or about 3O⁰C. [0054] In certain embodiments, the dosage formulations provided herein can further comprise one or more other antiviral agents, such as an antiviral peptide. Other antiviral agents which can be used in the compositions, either by themselves or as part of a combinatorial therapy regime, include but are not limited to DP 107 (T21) or any other antiviral polypeptide, such as those described in U.S. Patent No. 6,541 ,020 B1 , incorporated herein by reference in its entirety. Other exemplary, non-limiting examples of therapeutic agents include antiviral agents such as cytokines, e.g., rlFN α, rlFN β, rlFN y; reverse transcriptase inhibitors, including but not limited to, abacavir, AZT (zidovudine), ddC (zalcitabine), nevirapine, ddl (didanosine), FTC (emtricitabine), (+) and (-) FTC, reverset, 3TC (lamivudine), GS 840, GW-1592, GW-8248, GW-5634, HBY097, delaviridine, efavirenz, d4T (stavudine), FLT, TMC 125, adefovir, tenofovir, and alovudine; protease inhibitors, including but not limited to, amprenivir, CGP-73547, CGP-61755, DMP-450, indinavir, nelfinavir, PNU-140690, ritonavir, saquinavir, telinavir, tipranovir, atazanavir, lopinavir, ABT378, ABT538 and MK639; inhibitors of viral mRNA capping, such as ribavirin; amphotericin B as a lipid-binding molecule with anti-HIV activity; castanospermine as an inhibitor of glycoprotein processing; viral entry inhibitors such as fusion inhibitors (enfuvirtide, T1249, other fusion inhibitor peptides, and small molecules), SCH-D, TNX-355 (Tanox Inc.), AMD-070 (AnorMED), Pro 140, Pro 542 (Progenies), FP-21399 (EMD Lexigen), BMS806, BMS-488043 (Bristol- Myers Squibb), maraviroc (Selzentry™) (Pfizer), ONO-4128, GW-873140, AMD-887, CMPD-167, and GSK-873,140 (GlaxoSmithKline); CXCR4 antagonist, such as AMD- 070); lipid and/or cholesterol interaction modulators, such as procaine hydrochloride (SP-01 and SP-01A); integrase inhibitors, including but not limited to, L-870, and 810; RNAseH inhibitors; inhibitors of rev or REV; inhibitors of vif (e.g., vif-derived proline-enriched peptide, HIV-1 protease N-terminal-derived peptide); viral processing inhibitors, including but not limited to betulin, and dihydrobetulin derivatives (e.g., PA-457); and immunomodulators, including but not limited to, AS- 101, granulocyte macrophage colony stimulating factor, IL-2, valproic acid, and thymopentin.

[0055] In a further embodiment, the dosage formulations provide herein are suitable for parenteral (e.g., intravenous, intraarterial, intramuscular, subcutaneous, intradermal or intraperitoneal) administration to a patient. [0056] In another embodiment, provided herein are devices, such as auto-injector devices (e.g., a pre-filled pen device) comprising a dosage formulation provided herein. In specific embodiments, the auto-injector comprises about 1 mg to about 2000 mg of T1144 or a derivative thereof. In other embodiments, the auto-injector comprises about 25 mg, about 50 mg, about 125 mg or about 250 mg of T1144 or a derivative thereof. In another embodiment, the auto-injector device comprises a dosage formulation consisting essentially of about 1 mg to about 2000 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier (e.g., water, saline or PBS). In a further embodiment, the auto-injector device comprises a dosage formulation consisting essentially of about 25 mg, about 50 mg, about 125 mg or about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier (e.g., water, saline or PBS). In another embodiment, the auto-injector device contains a pre-filled cartridge comprising T1144 or a derivative thereof. In certain embodiments, the pre-filled cartridge comprises a dosage formulation provided herein. In another embodiment, the pre-filled cartridge comprises a one, two, three, four, five, six or seven day supply of T1144 or a derivative thereof, wherein a "one day supply" is about 25 mg, about 50 mg, about 125 mg or about 250 mg of T1144 or a derivative thereof. Such pre-filled cartridges can further comprise a pharmaceutically acceptable carrier (e.g., water, saline or PBS). In certain embodiments, the pre-filled cartridge will contain a dosage formulation consisting essentially of about 25 mg, about 50 mg, about 125 mg or about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier (e.g., water, saline or PBS). T1144

[0057] T1144 (also referred to as TRI-1144) is a synthetic 38 amino acid peptide derived from the HIV gp41 sequence useful for inhibiting viral infusion and suppressing HIV. See U.S. Patent Application Publication No.2007-0179278-A1, published August 2, 2007, incorporated by reference herein in its entirety.

T1144 has the following amino acid sequence:

TTWEAWDRAIAEYAAR I EALLRALQEQQE KN EAALREL (SEQIDNO:1).

[0058] In one embodiment, Tϊ 144 contains an acetyl (Ac) group on the amino terminus and an amino (NH₂) group on the carboxy terminus (i.e., Ac-T TWEAWD RAIAEYAARI EALLRALQEQQEKNEAALRE L-NH₂). [0059] T1144 and derivatives thereof can routinely be produced via well-known methods, such as those described in U.S. Provisional Patent Application No. 60/995,318, filed September 25, 2007 and U.S. PCT International Application No. PCT/US2008/011147, filed September 25, 2008 (see in particular, Examples 1 and 4-12), each of which is incorporated by reference herein in its entirety. Illustrative methods for producing T1144 are also set forth in accompanying FIGS. 3 and 4. [0060] In certain embodiments, T1144 or a derivative thereof is isolated. Dosing Regimens

[0061] Further provided herein are dosing regimens for the administration of dosage formulations provided herein to a patient.

[0062] In one embodiment, provided herein are dosing regimens comprising daily administration of a dosage formulation comprising T1144 or a derivative thereof as provided herein to a patient.

[0063] In another embodiment, provided herein are dosing regimens comprising administration of a dosage formulation comprising T1144 or a derivative thereof as provided herein to a patient once in a 24 hour period.

[0064] In a specific embodiment, a dosage formulation comprising T1144 or a derivative thereof is continuously administered daily or once per 24 hour period for days, weeks, months or years. More particularly, treatment periods for a course of therapy can span one week, two weeks, three weeks, four weeks, five weeks, six weeks, seven weeks, eight weeks, nine weeks, ten weeks, eleven weeks, twelve weeks, thirteen weeks, fourteen weeks, four months, five months, six months, seven months, eight months, nine months, ten months, eleven months, one year, two years, three years, four years, five years or longer. In certain embodiments, the treatment periods can be interrupted by periods of rest which can span a day, one week, two weeks, three weeks, four weeks, five weeks, six weeks, seven weeks, eight weeks, nine weeks, ten weeks, eleven weeks, twelve weeks, thirteen weeks, fourteen weeks, four months, five months, six months, seven months, eight months, nine months, ten months, eleven months, one year, two years, three years, four years, five years or longer. Such determinations can be made by one skilled in the art (e.g., a physician).

[0065] In one embodiment, the dosage formulations provided herein can be administered by injection. In one embodiment, the dosage formulations provided herein can be administered by subcutaneous injection. [0066] In another embodiment, the dosage formulations provided herein can be administered by injection (e.g., subcutaenous injection) once a day or once per 24 hour period.

[0067] In another embodiment, the dosage formulations provided herein can be administered by injection (e.g., subcutaenous injection) once a day or once per 24 hour period for one or more days, one or more weeks, one or more months, or one or more years.

[0068] Each administration can comprise one, two, three or more injections. [0069] In one embodiment, the dosage formulations provided herein are administered at a volume of about 100μl, about 200μl, about 300μl, about 400μl, about 500μl, about 600μl, about 700μl, about 800μl, about 900μl, about 1000μl or more. In a particular embodiment, the dosage formulations provided herein are administered at a volume of about 1000μl or less or 400μl or less. Pharmokinetic Properties

[0070] In one embodiment, provided herein are methods for achieving desirable pharmacokinetic parameters (e.g., tι/₂, C_max, U_3x, AUC, CUF, Vz/F and MRT) over a dosage range of about 1 mg to about 500 mg T1144 or a derivative thereof, comprising administering a dosage formulation provided herein to a patient. In a specific embodiment, the pharmacokinetic parameters are linear and dose- proportional.

[0071] In a particular embodiment, provided herein are methods for achieving linear desirable pharmacokinetic parameters (e.g., Ua, C_maχ, t_max, AUC, CL/F, Vz/F and MRT) over a dosage range of about 25 mg to about 250 mg T1144 or a derivative thereof, comprising administering a dosage formulation provided herein to a patient.

[0072] In another embodiment, provided herein are methods for maintaining a plasma concentration of T1144 or a derivative thereof of greater than about 1 μg/ml in a patient for at least about 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 8, 12 or 24 hours or longer, comprising administering an effective amount of a dosage formulation comprising T1144 or a derivative thereof as provided herein to a patient. In a particular embodiment, the administration is parenteral. In a more particular embodiment, the administration is by injection. In a still more particular embodiment, the administration is subcutaneous. [0073] In another embodiment, provided herein are methods for achieving a C_max of about 1490 to about 149,000 ng/mL of T1144 or a derivative thereof comprising administering an effective amount of a dosage formulation comprising T1144 or a derivative thereof (e.g., about 25 mg to about 250 mg) as provided herein to a patient.

[0074] In another embodiment, provided herein are methods for achieving a t_max of about 10 to about 12 hours comprising administering an effective amount of a dosage formulation comprising T1144 or a derivative thereof (e.g., about 25 mg to about 250 mg) as provided herein to a patient.

[0075] In another embodiment, provided herein are methods for achieving a Uv of about 12 to about 20 hours comprising administering an effective amount of a dosage formulation comprising T1144 or a derivative thereof (e.g., about 25 mg to about 250 mg) as provided herein to a patient.

[0076] In another embodiment, provided herein are methods for achieving a clearance of about 0.10 to about 0.17 ml_/min/kg comprising administering an effective amount of a dosage formulation comprising T1144 or a derivative thereof

(e.g., about 25 mg to about 250 mg) as provided herein to a patient.

[0077] In another embodiment, provided herein are methods for achieving a MRT of about 24 hours comprising administering an effective amount of a dosage formulation comprising T1144 or a derivative thereof (e.g., about 25 mg to about 250 mg) as provided herein to a patient.

[0078] Further provided herein are methods of administering a dosage formulation comprising T1144 or a derivative thereof as provided herein to a patient in need thereof that provides an in vivo plasma profile with a 90% confidence interval for a natural-log transformed ratio within 80% to 125%, 90% to 115% or 95% to

110% for at least one of the following pharmacokinetic parameters for T1144 or a derivative thereof:

(a) a mean t_1/2 of 14.1 hours upon administration of 25 mg of T1144 or a derivative thereof, a mean U₁₂ of 13.3 hours upon administration of 50 mg of

T1144 or a derivative thereof, a mean ti_/2 of 14.7 hours upon administration of 125 mg of T1144 or a derivative thereof or a mean U/2 of 20.0 hours upon administration of 250 mg of T1144 or a derivative thereof;

(b) a mean C_max of 1490 ng/mL upon administration of 25 mg of T1144 or a derivative thereof, a mean C_maχ of 3125 ng/mL upon administration of 50 mg of T1144 or a derivative thereof, a mean C_max of 9945 ng/mL upon administration of 125 mg of T1144 or a derivative thereof or a mean C_max of 14,900 ng/mL upon administration of 250 mg of T1144 or a derivative thereof;

(c) a mean t_max of 10.0 hours upon administration of 25 mg of T1144 or a derivative thereof, a mean t_max of 12.0 hours upon administration of 50 mg of T1144 or a derivative thereof, a mean t_max of 11.0 hours upon administration of 125 mg of Tϊ 144 or a derivative thereof or a mean t_max of 12.0 hours upon administration of 250 mg of T1144 or a derivative thereof

(d) a mean AUC of 35,550 h*ng/ml_ upon administration of 25 mg of T1144 or a derivative thereof, a mean AUC of 95,868 h*ng/ml_ upon administration of 50 mg of T1144 or a derivative thereof, a mean AUC of 267,840 h^*ng/ml_ upon administration of 125 mg of T1144 or a derivative thereof or a mean AUC of 480, 110 h*ng/ml_ upon administration of 250 mg of T1144 or a derivative thereof;

(e) a mean CL/F of 0.703 L/h upon administration of 25 mg of T1144 or a derivative thereof, a mean CL/F of 0.522 L/h upon administration of 50 mg of T1144 or a derivative thereof, a mean CL/F of 0.467 L/h upon administration of 125 mg of T1144 or a derivative thereof or a mean CL/F of 0.521 L/h upon administration of 250 mg of T1144 or a derivative thereof;

(f) a mean Vz/F of 14.3 L upon administration of 25 mg of T1144 or a derivative thereof, a mean Vz/F of 10.3 L upon administration of 50 mg of T1144 or a derivative thereof, a mean Vz/F of 11.5 L upon administration of 125 mg of T1144 or a derivative thereof or a mean Vz/F of 14.4 L upon administration of 250 mg of

T1144 or a derivative thereof; or

(g) a mean MRT of 23.5 hours upon administration of 25 mg of T1144 or a derivative thereof, a mean MRT of 24.0 hours upon administration of 50 mg of T1144 or a derivative thereof, a mean MRT of 24.1 hours upon administration of 125 mg of T1144 or a derivative thereof or a mean MRT of 25.2 hours upon administration of 250 mg of T1144 or a derivative thereof.

Methods of Use

[0079] Further provided herein are methods of using dosage formulations and dosing regimens provided herein. In one embodiment, the dosage formulations or dosing regimens are used as a part of a therapeutic regimen, for example, an antiviral therapeutic regimen. In certain embodiments, such a therapeutic regimen can, for example, be used for the therapy of HIV infection. [0080] In one embodiment, provided herein are methods of using the dosage formulations and dosing regimens provided herein for inhibition of transmission of HIV to a target cell, comprising administering an amount of a dosage formulation provided herein to a patient such that the target cell is contacted with an amount of T1144 or a derivative thereof effective to inhibit infection of the cell by the virus. This method can, for example, be used to treat HIV-infected patients. In one embodiment, inhibiting transmission of HIV to a target cell comprises inhibiting gp41- mediated fusion of HIV-1 to a target cell and/or inhibiting syncytia formation between an HIV-infected cell and a target cell.

[0081] Also provided herein are methods of treating HIV infection (in one embodiment, HIV-1 infection) comprising administering to an HIV-infected patient a dosage formulation provided herein in an amount effective to treat the HIV infection. In one embodiment, the dosage formulation comprises an amount of T1144 or a derivative thereof effective to inhibit transmission of HIV to a target cell, and/or an amount of an HIV fusion inhibitor peptide effective to inhibit gp41-mediated fusion of HIV to a target cell. These methods can, for example, be used to treat HIV-infected patients.

[0082] In a particular embodiment, provided herein are methods for ameliorating a symptom associated with an HIV infection, comprising administering to an HIV infected patient a dosage formulation provided herein.

[0083] Further provided herein are methods for the use of a dosage formulation provided herein in the manufacture of a medicament for use in therapy of HIV infection (e.g., used in a method of inhibiting transmission of HIV, a method of inhibiting HIV fusion, and/or a method of treating HIV infection). The medicament can be in the form of a pharmaceutical composition comprising T1144 or a derivative thereof and optionally one or more pharmaceutically acceptable carriers. In a particular embodiment, the pharmaceutically acceptable carrier is water or saline. In another embodiment, the medicament does not contain a gelling material. In a further embodiment, the medicament consists essentially of T1144 or a derivative thereof and water or saline. In a further embodiment, the medicament comprises isolated T1144 or a derivative thereof. Examples

EXAMPLE 1 [0084] The following example describes a Phase 1 clinical study of T1144. [0085] Methodology: This was a blinded, placebo-controlled single-dose, escalation study. Healthy subjects were randomized to receive T1144 or placebo (saline) via subcutaneous injection. Serial plasma samples for pharmacokinetic (PK) analyses, plus adverse event (AE) and injection-site reactions were collected through 7 days post-dose. Twenty-four subjects were enrolled and dosed at 25 mg (N=3), 50 mg (N=6), 125 mg (N=6), 250 mg (N=3) or saline (N=6). All subjects completed the study. Table 1 provides a summary of the dosing cohorts. Table 2 provides a summary of subject demographics. Table 1

Table 2

[0086] Results: PK values were linear over the dose range. Mean values for Cmax ranged from 1.4 to 16.3 mg/mL, mean values for CL2₄ (clearance over 24 hours) ranged from 0.67 to 12.4 mg/mL, mean values for AUC ranged from 34.2 to 489.3 h^*mg/mL, mean values for U_/2 ranged from 13.4 to 19.7 hours, and the median value for t_max was about 11 hours (dose independent). Table 3 provides an overall summary of median PK values. Table 3

[0087] Safety and Tolerabilitv: T1144 was generally safe and well-tolerated at doses of 25 mg to 250 mg. 8/24 subjects experienced 10 AE's, with seven being mild (four considered possibly related) and three moderate but unrelated. More Subjects experienced treatment-emergent drug-related AE's in the placebo group than across all four t1144 dosing groups combined. 17/24 subjects experienced a Grade 1 or greater ISR. All subjects in the 50 mg, 125 mg and 250 mg T1144 dosing groups experienced at least one ISR sign or symptom. The most frequently noted ISR signs or symptoms were erythema, pain/discomfort and induration. Most were resolved by 96 hours post-dose. No nodules or cysts were noted and no ISR was observed in the 25 mg group.

[0088] Conclusions: T1144 displayed nearly linear and dose-proportional PK over the 25 mg to 250 mg dose range (FIGs. 6 and 7). Inter-subject variability was low for all PK parameters. Absorption T1144 was well-tolerated by all subjects in this Phase 1 study. PK analyses suggest that a 25 mg to 50 mg daily dose of T1144 could achieve therapeutic plasma levels (i.e., about 1 mg/mL) (FIG. 5). PK parameters for T1144 in humans are superior to those of enfuvirtide. The mean ti/2 for enfuvirtide was 3.8 ± 0.6 hours and the mean CUf (apparent clearance) for enfuvirtide was 0.413 ± 4.1 mL/min/kg following a single 90 mg subcutaneous does of enfuvirtide. T1144 also show superior PK relative to enfuvirtide in mouse, rat and cyno monkey models (FIG. 8). Accordingly, T1144 appears to be an excellent fusion inhibitor candidate and may offer advantages over enfuvirtide in the clinic. [0089] The foregoing description of the specific embodiments provided herein has been described in detail for purposes of illustration. In view of the descriptions and illustrations, others skilled in the art can, by applying current knowledge, readily modify and/or adapt the embodiments for various applications without departing from the basic concept; and thus, such modifications and/or adaptations are intended to be within the meaning and scope of the embodiments provided herein.

Claims

What is claimed is:

1. An injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier.

2. A method for administering T1144 or a derivative thereof, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient.

3. A method for achieving a linear and dose-proportional pharmacokinetic parameter over a dosage range of about 25 mg to about 250 mg T1144 or a derivative thereof, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient, wherein the pharmacokinetic parameter is selected from the group consisting of Ui₂, C_max, t_maX) AUC, CUF, Vz/F and MRT.

4. A method of treating HIV infection, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient.

5. A method for inhibition of the transmission of HIV to a target cell in a patient, comprising daily administration of an injectable dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier to a patient.

6. A Mthod for the manufacture of a medicament comprising a dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier for use in therapy of HIV infection.

7. An auto-injector device comprising a dosage formulation consisting essentially of about 25 mg to about 250 mg of T1144 or a derivative thereof and a pharmaceutically acceptable carrier.