Provided herein are pharmaceutical compositions for the prophylactic and therapeutic treatment of HIV comprising combinations of HIV fusion/entry inhibitors that exhibit synergistic effect, including T-20 (enfuvirtide), T-1249, T-1144, C34, and sifuvirtide. Also disclosed are methods of treating HIV infection by administering such compositions.

Description of the Invention

SUMMARY OF THE INVENTION

Combinations of anti-HIV drugs targeting different sites on gp41 results in exceptionally potent synergistic anti-HIV activity. These findings suggest that administration of the HIV fusion/entry inhibitors targeting the different sites in gp41 or with different mechanisms of action may significantly increase the efficacy of the anti-HIV drugs, lead to a decrease in toxic effects, reduction of the amount and frequency of drug use, and consequently, these highly effective peptidic anti-HIV drugs will become more affordable to HIV/AIDS patients.

In one embodiment of the present disclosure a pharmaceutical composition is provided comprising a synergistic combination of two or more human immunodeficiency virus (HIV) fusion/entry inhibitors in amounts effective for treatment of HIV. In another embodiment, the HIV fusion/entry inhibitors target different regions in the HIV envelope glycoprotein transmembrane subunit of gp41. In another embodiment, the HIV fusion/entry inhibitors have different mechanisms of action.

In another embodiment, at least one of the HIV fusion/entry inhibitors is selected from the group consisting of an antibody targeting gp41, a peptide derived from gp41 or targeting gp41, a protein targeting gp41, a recombinant protein or polypeptide targeting gp41, and a small molecule organic compound targeting gp41.

In another embodiment, the antibodies targeting gp41 are monoclonal antibodies selected from the group consisting of 2F5, 4E10, Z13, and D5.

In yet another embodiment, the peptides targeting gp41 are selected from the group consisting of C28, C34, C35-EK, sifuvirtide, C36, C38, T-1144, T267227, T2635, C43, C46, CP32, CP32M, T-1249, PBD-4HR, PBD-4HRa, PBD-4HRb, PBD-4HRc, D10-p1-2K, D10-p5-2K, PIE7, CBD1, T-20, T-20-A, 4HR-LBD, 4HRa-LBD, 4HRb-LBD, 4HRc-LBD, N34, N36, N46, N51, DP-107, IQN17, ccIZN17, IZN28, IZN36, N34ccg, and VIRIP.

In yet another embodiment, the recombinant proteins or polypeptides targeting gp41 are selected from the group consisting of C52L, 5-Helix, N36ccg-N13, HR121, and HR212.

In yet another embodiment, the small molecule organic compounds are selected from the group consisting ADS-J1, NB-2, and NB-64.

In one embodiment, disclosed herein is a method of treating or preventing human immunodeficiency virus (HIV) infection comprising the steps of: administering a first HIV fusion/entry inhibitor; administering a second HIV fusion/entry inhibitor; and treating or preventing infection with HIV. In another embodiment, the method further comprises the step of administering a third HIV fusion/entry inhibitor. In another embodiment, the method further comprises the step of administering a fourth HIV fusion/entry inhibitor.

In another embodiment, the first and second HIV fusion/entry inhibitors are administered in a sequential manner, wherein each therapeutic agent is administered at a different time.

In another embodiment, the first and second HIV fusion/entry inhibitors are administered in a substantially simultaneous manner, by administering to the subject a dosage form comprising a single dosage unit comprising therein the desired doses of two or more HIV fusion/entry inhibitors or multiple dosage units, each dosage unit comprising a single HIV fusion/entry inhibitor.

In another embodiment, the administration is by a route selected from the group consisting of oral, topical, intravenous, intramuscular, and direct absorption through mucous membrane tissues. In another embodiment, each HIV fusion/entry inhibitor is individually administered by the same or by different routes. In yet another embodiment, the first HIV fusion/entry inhibitor is administered by intravenous injection and the second HIV fusion/entry inhibitor is administered orally.

DETAILED DESCRIPTION OF THE INVENTION

The phrase "combination therapy" (or "co-therapy") refers the administration of two or more HIV fusion/entry inhibitors as part of a specific treatment or prevention regimen intended to provide a beneficial effect from the co-action of these therapeutic or prophylactic agents. The beneficial effect of the combination includes, but is not limited to, increased drug potency, deceased toxic effects, reduction in the amount and frequency of drug use, slowed development of drug-resistance, and improved pharmacokinetics or pharmacodynamics.

Administration of these therapeutic or prophylactic agents (hereinafter "compositions" or "agents") in combination typically is carried out over a defined time period. "Combination therapy" embraces administration of these HIV fusion/entry inhibitors in a sequential manner (i.e., each therapeutic or prophylactic agent is administered at a different time) or in a substantially simultaneous manner (e.g., administering to the subject a single dosage unit having a fixed ratio of each agent or in multiple, single dosage units for each agent). As used herein, the "dosage unit" refers to a physically discrete unit that contains a predetermined quantity of active ingredient calculated to produce a desired therapeutic or prophylactic effect. The unit dose or unit dosage may be in the form of tablet, capsule, inhalation capsule, suppository, oral or intravenous or topical solution or suspension, gel, or film, etc. For example, one embodiment of the present composition provides T-20 (the first generation HIV fusion inhibitor) and T-1249 (the second generation HIV fusion inhibitor) formulated as individual dosage units or a single, co-formulated dosage unit comprising the two compounds. In another example embodiment, the composition comprises T-20 and T1144 (the third generation HIV fusion inhibitor) as separate pharmaceutical composition dosage units that can be administered at the same or different time. As a further example embodiment, the composition comprises T-20, T1249 and T1144 as separate pharmaceutical composition dosage units that can be administered at the same or different time. Sequential or substantially simultaneous administration of each inhibitor can be effected by any appropriate route including, but not limited to, intravenous routes, intramuscular routes, oral routes, intravaginal routes, intrarectal routes, and direct absorption through mucous membrane tissues. Each HIV fusion/entry inhibitor can be administered by the same route or by different routes. For example, one component (e.g., T-20) may be administered by intravenous injection while the other component (e.g., NB-2) of the combination may be administered orally. The components may be administered in any therapeutically or prophylactically effective sequence.

The term "HIV fusion/entry" refers to a critical step of virus life cycle necessary for a virion or HIV-infected cell fusing with or entering into a target vesicle or cell.

The term "HIV fusion/entry inhibitor" refers to any agent that blocks HIV or HIV-infected cell fusion with or entry into a target vesicle or cell. HIV fusion/entry inhibitors include, but are not limited to peptides, small molecules and antibodies.

As used herein, the term "synergism" or "synergistic," when referring to synergism between drugs, means that the drugs interact in ways that enhance or magnify one or more effects, or side effects, of those drugs. This is sometimes exploited in combination preparations. The combination causes a greater effect than simply the sum of the individual effects of each drug if they were used separately.

HIV fusion/entry inhibitor antibodies include, but are not limited to, 2F5 (anti-HIV-1 gp41 monoclonal antibody; Buchacher A et al. AIDS Res. Human Retroviruses 10:359-369, 1994), 4E10 (anti-HIV-1 gp41 monoclonal antibody; Stiegler G et al. AIDS Res. Human Retroviruses 17:1757-1765, 2001), Z13 (IgG1 anti-HIV-1 gp41 monoclonal antibody; Zwick M B et al. J. Virol. 75:10892-905, 2001), and D5 (human anti-HIV-1 gp41 monoclonal antibody; Miller M D et al. Proc. Natl. Acad. Sci. 102:14759-14764, 2005).

SJ-2176 (SEQ ID NO:3), C34 (SEQ ID NO:5), C36 (SEQ ID NO:8), and C38 (SEQ ID NO:9), and other CHR-peptides containing the pocket-binding domain are believed to inhibits HIV fusion/entry by interacting with the HIV gp41 NHR and pocket regions, and blocking the formation of the six-helix bundle core of gp41. T-20, which contains the NHR- and lipid-binding domains but lacks the pocket-binding domain, may inhibit HIV fusion/entry by interacting with the HIV gp41 NHR region and lipid membrane.

T-1249 (SEQ ID NO:34), a second generation HIV fusion/entry inhibitor, is a 39-mer hybrid polypeptide consisting of a core peptide linked by a pocket-binding domain and a lipid-binding domain at the N- and C-termini, respectively. Therefore, it may inhibit HIV fusion/entry by interacting with the HIV gp41 NHR and pocket regions as well as the lipid membrane. T-1249 has a longer half-life than T-20 in primates and different resistant profiles. Clinical studies have shown that T-1249 exhibits greater anti-HIV-1 potency than T-20 and is active against some of T-20-resistant HIV-1 variants), indicating that T-1249 targets a different region from that of T-20 within the gp41 NHR.

T-1144 (SEQ ID NO:10), a 38-mer peptide, has been developed as the third generation HIV fusion/entry inhibitor. Like C38, T-1144 also contains the NHR- and pocket-binding domains, and is expected to inhibit HIV fusion/entry by interacting with the HIV gp41 NHR and pocket regions, and blocking the formation of the six-helix bundle core of gp41. T-1144 was designed by modifying the amino acid sequence of C38 to increase the helicity and six-helix bundle stability. It is thousands fold more active than T-20 against viruses that are resistant to T-20. The pharmacokinetic properties of T-1144 were improved up to 100-fold. The potent antiviral activity against resistant viruses, the difficulty in generating resistant virus, and the extended half-life in vivo make T-1144 attractive for further development.

Sifuvirtide (SEQ ID NO:7), a 36-mer peptide, was designed by modification of the CHR-peptide C36 based on three-dimensional (3D) structural information of HIV-1 gp41 and computer modeling analysis to favor its stability, pharmacokinetics, and antiviral potency. Like C36, sifuvirtide also contains the NHR- and pocket-binding domains. It may inhibit HIV fusion/entry by interacting with the HIV gp41 NHR and pocket regions, and blocking the formation of the six-helix bundle core of gp41. Sifuvirtide inhibited HIV-1-mediated cell-cell fusion in dose-dependent manner and exhibited higher potency than T-20 against infections by a wide range of primary and laboratory-adapted HIV-1 isolates from multiple genotypes with R5 or X4 phenotypes. Sifuvirtide was highly effective against T-20-resistant strains. Phase Ia clinical studies of sifuvirtide in healthy individuals demonstrated good safety, tolerability and pharmacokinetic profiles. Pharmacokinetic studies of single and multiple administration of sifuvirtide showed that its decay half-life was 20.0.+-.8.6 hr and 26.0.+-.7.9 hr, respectively.

CP32 (SEQ ID NO:16) is a 32-mer peptide containing the NHR- and pocket-binding domains and a motif (QIWNNMT, SEQ ID NO:54), which is located at the upstream region of the CHR and immediately adjacent to the pocket-binding domain and is highly important for the stabilization of the gp41 core structure. CP32 can interact with NHR-peptide T-21, a counterpart peptide derived from the NHR, to form a typical six-helix bundle structure with higher thermostability (Tm=81.degree. C.) than that formed by the peptides N36 and C34 (Tm=65.degree. C.). CP32 could efficiently bind to the gp41 pocket region and block six-helix bundle formation in a dose-dependent manner. Significantly, CP32 has potent inhibitory activity against HIV-1-mediated cell-cell fusion and infection by primary HIV-1 isolates. Unlike T-20 and C34 however, CP32 does not contain the GIV-binding sequence. Therefore, the mutations of GIV motif may have little or no effect at all on the interaction of CP32 with the viral gp41 NHR region, and consequently CP32 is very effective against HIV-1 strains resistant to T-20 and C34.

CP32M (SEQ ID NO:17) is an analogous peptide of CP32 with improved thermostability (Tm=94.degree. C.) and enhanced anti-HIV-1 activity, especially against HIV-1 strains resistant to T-20, C34 and T-1249.

5-Helix is composed of three N-peptides (N40, residues 543-582) and two C-peptides (C-38, residues 625-662), connected by -GGSGG-linkers. Under physiological conditions, 5-Helix is well folded, soluble and extremely stable with a typical .alpha.-helical conformation. Because 5-Helix contains five of the six helices and has one groove exposed on the surface, it can attract one of the gp41 C-helices to fill in the gap and prevent the formation of fusion-active six-stranded gp41 core, thus blocking HIV-mediated membrane fusion. The high potency of 5-Helix against HIV infection (nanomolar EC.sub.50) suggests that this polypeptide may be developed as a new anti-HIV therapeutic for preventing HIV entry. Furthermore, an exotoxin protein from a Pseudomonas strain was conjugated to the 5-Helix. This chimeric fusion protein can specifically bind to the CHR region of the viral gp41 expressed on the HIV-1-infected cells. Therefore, this recombinant toxin, like a "biological missile", can specifically attack the HIV-1-infected cells by killing these cells with its toxin component or block fusion of the HIV-1-infected cells with uninfected cells with its 5-Helix.

N35ccg-N13 (SEQ ID NO:49) and N34ccg (SEQ ID NO:48), are NHR-peptides, in which Leu576, Gln577 and Ala578 were replaced with Cys, Cys and Gly, respectively. These two NHR-peptides can form helical trimers which are stabilized by three intermolecular disulfide bonds. N35ccg-N13 and N34ccg can interact with the gp41 CHR domain and inhibit the HIV-induced cell-cell fusion with EC.sub.50 values of 15 and 95 nM, respectively.

HR121 (SEQ ID NO:50) and HR212 (SEQ ID NO:22) are recombinant proteins with potent anti-HIV-1 activity. HR121 contains two molecules of N-peptide (N34) derived from the NHR (or HR1) region and one molecule of C-peptide (C34) derived from the gp41 CHR (or HR2) region connected by linkers in the order of HR1-HR2-HR1. Similarly, HR212 consists of two molecules of C-peptide (C34) and one molecule of N-peptide (N34) linked in the order of HR2-HR1-HR2. The rational for this design is that three heptad repeats (two N-peptides and one C-peptide, or one C-peptide and two N-peptides) are linked by flexible linkers so that N- and C-peptides in each protein can associate to form a hairpin structure. As a consequence, three molecules can form a stable six-helix bundle with three free N- or C-peptides exposed, which may bind to the counterpart regions in the viral gp41, thereby blocking gp41-mediated membrane fusion. Both HR121 and HR212 can be abundantly expressed and easily purified, exhibiting a stable .alpha.-helical character as shown in CD spectroscopy. The recombinant proteins HR121 and HR212 had potent inhibitory activity on HIV-1 Env-mediated cell-cell fusion with EC.sub.50 values in low nanomolar range, being comparable to the potency of C-peptides, T-20 and C34 and much better than the N-peptides, T-21 and N36. These data suggest that HR121 and HR212 can be potentially developed as therapeutic agents, in a manner analogous to synthetic C-peptides, but may be much less expensive than the synthetic peptides since these recombinant protein can be easily expressed and purified in large scale.

D10-p1-2K (SEQ ID NO:23), D10-p5-2K (SEQ ID NO:24) and PIE7 (SEQ ID NO:25) are short peptides consisting of all D-amino acids which are resistant to proteolytic enzymes. These peptides can specifically bind to the gp41 hydrophobic pocket presented on the NHR-trimer modeled by IQN17, which was confirmed by X-ray crystallography and nuclear magnetic resonance (NMR). D10-p5-2K and PIE7 can inhibit HIV-1 infection with EC.sub.50 in low micromolar range. These anti-HIV D-peptides are expected to be resistant to proteolytic degradation.

ADS-J1 is the first small molecule HIV fusion/entry inhibitor identified with a series of high throughput screening (HTS) assays, including the virtual screening method based on computer modeling to screen for compounds with potential to dock into the deep hydrophobic pocket on the gp41 N-helix trimer and ELISA and cell fusion assays for compounds with inhibitory activity against gp41 six-helix bundle formation and HIV-1-mediated membrane fusion, respectively. ADS-J1 inhibited HIV replication, HIV-1 mediated cell-cell fusion and the gp41 6-HB formation with EC.sub.50 is in low .mu.M range (Debnath A K et al. J Med Chem 42:3203-3209, 1999).

NB-2 and NB-64, the N-substituted pyrroles, were identified from a chemical library consisting of 33,040 "drug-like" compounds from ChemBridge Corp using HTS assays (Jiang S et al. Antimicrob Agents Chemother 48:4349-4359, 2004). NB-2 and NB-64 may bind to the gp41 pocket and block the 6-HB formation. These compounds inhibited infection by both laboratory-adapted and primary HIV-1 strains with distinct genotypes (clades A to G and group O) and phenotypes (R5, X4 and R5X4) at low micromolar levels. NB-2 and NB-64 effectively inhibited HIV-1 Env-mediated cell-cell fusion and blocked the formation of the fusion-active gp41 6-HB as demonstrated by several assay systems, such as ELISA, FN-PAGE and CD analysis. Computer-aided molecular docking analysis has shown that both compounds fit inside the hydrophobic pocket and their COOH group interacts with a positively charged residue (K574) around the pocket to form a salt bridge, thereby blocking the formation of the 6-HB and ultimately inhibiting HIV-1 mediated membrane fusion.

The term "therapeutic effect" refers to one or more of the following: 1) inhibition of fusion of a virion or HIV-infected cell with a target cell; 2) inhibition of HIV replication; 3) reduction in the number of infected cells; 4) reduction in the concentration of virions present in serum; 5) increasing T-cell count; 6) relieving or reducing to some extent one or more of the symptoms associated with HIV; and 7) relieving or reducing the side effects associated with the administration of other antiretroviral agents. "Therapeutically effective amount" is intended to qualify the amount required to achieve a therapeutic effect.

The term "prophylactic effect" refers to prevention of a virion or HIV-infected cell to enter into and replicate in a target cell.

"Prophylactically effective amount" is intended to qualify the amount required to achieve a preventive effect

The terms "EC.sub.50" and "EC.sub.90" refer to the drug concentration that results in a 50% and 90% reduction, respectively, in virus replication or virus-mediated cell fusion.

As used herein, the term "inhibit," "inhibition," "inhibitory" and "inhibitory activity" refers to slowing, decreasing, interrupting, arresting or suppressing HIV assembly, maturation and replication activity so as to enable prolonging the survivability of the patient. In some embodiments, the claimed composition may suppress 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% of the retroviral activity. IC.sub.50 is well understood by a person of skill in the art to be the accepted measure of the effectiveness of inhibition. The measurement indicates how much of a particular substance is necessary to decrease or inhibit a particular activity by 50%.

As used herein "prodrug" refers to a compound which is converted to a therapeutically active compound after administration, and the term should be interpreted as broadly herein as is generally understood in the art. While not intending to limit the scope of the present description, conversion may occur by hydrolysis of an ester group or some other biologically labile group. Generally, but not necessarily, a prodrug is inactive or less active than the therapeutically active compound to which it is converted. Ester prodrugs of the compounds disclosed herein are contemplated.

The term "therapeutically effective amount" or "pharmaceutically effective amount" means an amount of composition sufficient to, when administered to a subject suffering from or susceptible to HIV infection and/or one or more associated diseases, disorders or conditions, treat HIV infection and/or associated disease(s), disorder(s) or condition(s).

The terms "treat," "treatment" or "treating," as used herein, refer to partially or completely alleviating, inhibiting, preventing, curing, delaying the onset of, reducing incidence of, ameliorating and/or relieving one or more symptoms or features of a particular disease, disorder or condition (e.g., HIV infection).

The pharmaceutical compositions herein disclosed comprise a therapeutically effective amount of HIV-1 fusion/entry inhibitor formulated for administration to a subject at risk of infection with HIV or to a patient suffering from or susceptible to an HIV infection and/or an associated disease, disorder or condition. Some of the disclosed compositions include at least one pharmaceutically acceptable excipient and may optionally include at least one additional therapeutically active agent.

The disclosed fusion/entry inhibitors may be administered in free form or, where appropriate, as a pharmaceutically acceptable derivative thereof. In some embodiments, the disclosed compounds are administered in a salt form; in other embodiments, the compounds are administered in an ester or prodrug form.

Appropriate excipients for use in the present pharmaceutical compositions may include, for example, one or more carriers, binders, fillers, vehicles, disintegrants, surfactants, dispersion or suspension aids, thickening or emulsifying agents, isotonic agents, preservatives, lubricants, and the like or combinations thereof, as suited to a particular dosage from desired. Remington's Pharmaceutical Sciences, Sixteenth Edition, E. W. Martin (Mack Publishing Co., Easton, Pa., 1980) discloses various carriers used in formulating pharmaceutically acceptable compositions and known techniques for the preparation thereof. This document is incorporated herein by reference in its entirety.

The disclosed compositions may be formulated for any desirable route of delivery including, but not limited to, parenteral, intravenous, intradermal, subcutaneous, oral, topical, inhalative, transdermal, topical, transmucosal, rectal, interacisternal, intravaginal, intraperitoneal, bucal and intraocular.

In certain aspects, parenteral, intradermal or subcutaneous formulations may be sterile injectable aqueous or oleaginous suspensions. Acceptable vehicles, solutions, suspensions and solvents may include, but are not limited to, water or other sterile diluent; saline; Ringer's solution; sodium chloride; fixed oils such as mono- or diglycerides; fatty acids such as oleic acid; polyethylene glycols; glycerine; propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol; antioxidants such as ascorbic acid; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates; and agents for the adjustment of tonicity such as sodium chloride or dextrose.

Solutions or suspensions used for parenteral, intradermal, or subcutaneous application may include one or more of the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine; propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfate; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. The pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation may be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

Pharmaceutical compositions suitable for injectable use may include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include, but are not limited to, saline, bacteriostatic water, CREMOPHOR EL.RTM. (BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). The solvent or dispersion medium may contain, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol, and the like), and suitable mixtures thereof. Proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the requited particle size in the case of dispersion and by the use of surfactants. Preventing growth of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. The composition may also include isotonic agents such as, for example, sugars; polyalcohols such as manitol; sorbitol; or sodium chloride. Prolonged absorption of injectable compositions can be enhanced by addition of an agent which delays absorption, such as, for example, aluminum monostearate or gelatin.

Oral compositions may include an inert diluent or an edible carrier. They may be enclosed in gelatin capsules or compressed into tablets. Tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose; a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or sterites; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring.

Systemic administration may be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants may be used. Such penetrants are generally known in the art, and include, for example, detergents, bile salts, and fusidic acid derivatives. Transdermal administration may include a bioactive agent and may be formulated into ointments, salves, gels, or creams as generally known in the art. Transmucosal administration may be accomplished through the use of nasal sprays or suppositories.

Pharmaceutical compositions and formulations for topical administration may include transdermal patches, ointments, lotions, creams, gels, drops, suppositories, sprays, liquids and powders. Conventional pharmaceutical carriers, aqueous, powder or oily bases, thickeners and the like may be necessary or desirable. Coated condoms, gloves and the like may also be useful.

For administration topically to external tissues e.g., mouth, skin, vagina, rectum, etc., the formulations may applied as a topical ointment, cream or gel containing the active ingredient(s) in an amount of, for example, 0.075 to 20% w/w (including active ingredient(s) in a range between 0.1% and 20% in increments of 0.1% w/w such as 0.6% w/w, 0.7% w/w, etc.), preferably 0.2 to 15% w/w and most preferably 0.5 to 10% w/w. When formulated in an ointment, the HIV-1 fusion/entry inhibitors may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active ingredients may be formulated in a cream with an oil-in-water cream base.

If desired, the aqueous phase of the cream base may include, for example, at least 30% w/w of a polyhydric alcohol, i.e. an alcohol having two or more hydroxyl groups such as propylene glycol, butane 1,3-diol, mannitol, sorbitol, glycerol and polyethylene glycol (including PEG 400) and mixtures thereof. The topical formulations may desirably include a compound which enhances absorption or penetration of the HIV-1 fusion/entry inhibitors through the skin or other affected areas. Examples of such dermal penetration enhancers include dimethyl sulphoxide and related analogs.

The oily phase of the emulsions may be constituted from known ingredients in a known manner. While the phase may comprise merely an emulsifier (otherwise known as an emulgent), it desirably comprises a mixture of at least one emulsifier with a fat or an oil or with both a fat and an oil. Preferably, a hydrophilic emulsifier is included together with a lipophilic emulsifier which acts as a stabilizer. It is also preferred to include both an oil and a fat. Together, the emulsifier(s) with or without stabilizer(s) make up the so-called emulsifying wax, and the wax together with the oil and fat make up the so-called emulsifying ointment base which forms the oily dispersed phase of the cream formulations.

Emulgents and emulsion stabilizers suitable for use in the formulation include TWEEN.RTM. 60, SPAN.RTM. 80, cetostearyl alcohol, benzyl alcohol, myristyl alcohol, glyceryl mono-stearate and sodium lauryl sulfate.

The choice of suitable oils or fats for the formulation is based on achieving the desired cosmetic properties. The cream should preferably be a non-greasy, non-staining and washable product with suitable consistency to avoid leakage from tubes or other containers. Straight or branched chain, mono- or dibasic alkyl esters such as di-isoadipate, isocetyl stearate, propylene glycol diester of coconut fatty acids, isopropyl myristate, decyl oleate, isopropyl palmitate, butyl stearate, 2-ethylhexyl palmitate or a blend of branched chain esters known as Crodamol CAP may be used, the last three being preferred esters. These may be used alone or in combination depending on the properties required. Alternatively, high melting point lipids such as white soft paraffin and/or liquid paraffin or other mineral oils are used.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the HIV-1 fusion/entry inhibitors such carriers as are known in the art to be appropriate

The disclosed HIV-1 fusion/entry inhibitors are useful in treating HIV-1 infections and/or associated diseases, disorders and conditions. The pharmaceutical compositions comprising at least one fusion/entry inhibitor may be administered to individuals suffering from or susceptible to HIV-1 infection.

The pharmaceutical compositions comprising the fusion/entry inhibitors may be administered in a therapeutically effective amount, according to an appropriate dosing regiment. As understood by a skilled artisan, an exact amount required may vary from subject to subject, depending on a subject's species, age and general condition, the severity of the infection, the particular agent(s) and the mode of administration. In some embodiments, about 0.001 mg/kg to about 50 mg/kg, of the pharmaceutical composition based on the subject's body weight is administered, one or more times a day, to obtain the desired therapeutic effect. In other embodiments, about 1 mg/kg to about 25 mg/kg, of the pharmaceutical composition based on the subject's body weight is administered, one or more times a day, to obtain the desired therapeutic effect.

A total daily dosage of the compounds and pharmaceutical compositions can be determined by the attending physician within the scope of sound medical judgment. A specific therapeutically effective dose level for any particular patient or subject will depend upon a variety of factors including the disorder being treated and the severity of the disorder; the activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient or subject; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed, and other factors well known in the medical arts.
 

Claim 1 of 10 Claims

1. A pharmaceutical composition comprising a synergistic combination of two or more human immunodeficiency virus (HIV) fusion/entry inhibitors in amounts effective for treatment of HIV, wherein the HIV fusion/entry inhibitors are selected from the group consisting of T-20 (enfuvirtide), T-1249, T-1144, C34, and sifuvirtide.
 

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