WO1998052571A1

WO1998052571A1 - Antiviral combinations containing the carbocyclic nucleoside 1592u89

Info

Publication number: WO1998052571A1
Application number: PCT/EP1998/002837
Authority: WO
Inventors: Martha Heider St. Clair; David Walter Barry
Original assignee: Glaxo Group Limited
Priority date: 1997-05-17
Filing date: 1998-05-14
Publication date: 1998-11-26
Also published as: NO995621L; EP1019056A1; BR9809124A; CA2289654A1; NZ500868A; JP2001525840A; NO995621D0; AU8017298A

Abstract

The present invention relates to therapeutic combinations of (-)-(1S, 4R)-4-[2-amino-6- (cyclopropylamino)-9H-purin-9-yl] -2-cyclopentene-1-methanol (1592U89) and HIV protease inhibitors which have anti-HIV activity. The present invention is also concerned with pharmaceutical compositions containing said combinations and their use in the treatment of HIV infections.

Description

ANTIVIRAL COMBINATIONS CONTAINING THE CARBOCYCLIC NUCLEOSIDE 1592U89

The present invention relates to therapeutic combinations of (-)-(l S, 4R) -4-[2-amino-6- (cyclopropylamino)-9H-purin-9-yl]-2-cyclopentene-1-methanol (1592U89) and HIV protease inhibitors, which have anti-HIV activity. The present invention is also concerned with pharmaceutical compositions containing said combinations and their use in the treatment of HIV infections including infections with HIV mutants bearing resistance to nucleoside and/or non-nucleoside inhibitors.

The therapeutic agent 1592U89 (European Specification EP0434450) is a promising anti- HIV chemotherapeutic candidate (International Conference on Antiviral Research, April 23, 1995) showing potent activity against Human Immunodeficiency Virus (HIV), the causative agent of Acquired Immune Deficiency Syndrome (AIDS), low cytotoxicity and excellent penetration into the brain which is important for the treatment of AIDS and

HIV linked central nervous system conditions such as AIDS dementia complex.

Inhibitors of HIV protease have potent activity against HIV and related conditions such as AIDS-related Complex (ARC). Examples of HIV protease inhibitor compounds include those disclosed in WO 94/05639, WO 95/24385, WO 94/13629, WO 92/16501 , WO

95/16688, W0/US94/13085, W0/US94/12562, US 93/59038, EP 541 168, WO 94/14436, WO 95/09843, WO 95/32185, WO 94/15906, WO 94/15608, WO 94/04492, WO 92/08701 , WO 95/32185, and U.S. Patent No. 5,256,783, in particular (S)-N- ((.alpha.S)-((l R)-2-((3S, 4αS,8αS)-3-(tert-Butylcarbamoyl)octahydro-2-(l H)-isoquinolyl)-1- hydroxyethyl)phenethyl)-2-quinaldaminosuccinamide monomethanesulfonate

(saquinavir), N-(2(R)-Hydroxy-1 (S)indanyl)-2(R)-(phenylmethyl)-4(S)-hydroxy-5-[l -[4- (3-pyridylmethyl)-2(S)-(N-tert-butylcarbamoyl)piperazinyl]]pentaneamide (indinavir), 10- hydroxy-2-methyl-5-(1 -methylethyl)-1 -[2-(1-methylethyl)-4-thiazolyl]-3,6-dioxo-8,1 1 - bis(phenylmethyl)- 2,4,7,12-tetraazatridecan-13-oic acid, 5-thiazolylmethyl ester (ritonavir), ( N-(1 ,1-dimethyl)decahydro-2-[2-hydroxy-3-[(3-hydroxy-2- methylbenzoyl)amino]-4-(phenylthio)butyl]- 3-isoquinolinecarboxamide monomethanesulfonate (nelfinavir), ABT-378, BMS-234475 (lasinavir), PNU-140690, DMP-450, PD173606 and related compounds. The treatment of HIV infection has relied to a large extent upon monotherapy with nucleoside reverse transcriptase inhibitors such as zidovudine, didanosine (ddl), zaicitabine (ddC) and stavudine (d4T). However, these drugs eventually become less effective due either to the emergence of HIV resistant mutants or because of toxicity. Thus, new therapies are needed. Following the widespread clinical use of zidovudine in the treatment of such infections and conditions, it has been observed that in certain instances following prolonged treatment, the virus may develop a certain level of resistance to zidovudine and therefore a loss of sensitivity to the drug.

It has now been found that by combining 1592U89 and protease inhibitors, a synergistic anti-HIV effect is achieved. It is a feature of this invention that the use of such a drug combination will provide one or more of the following : synergistic antiviral effects, more complete viral suppression, viral suppression over a longer period, limit the emergence of drug resistant HIV mutants, and/or allow better management of drug-related toxicities.

According to one aspect of the invention there is provided a combination comprising 1592U89 or a physiologically functional derivative thereof, and at least one HIV protease inhibitor or a physiologically functional derivative thereof.

A further feature of the present invention is a combination comprising 1592U89, at least one HIV protease inhibitor, and a second reverse transcriptase inhibitor, such as lamivudine. The ratios of the components of such combinations will conveniently be the same as the ratios of the relevant compounds in the double combinations of the invention.

As used herein, the term "physiologically functional derivative" includes any physiologically acceptable solvate, salt, ether, ester, salt of such ester, or solvates of any such salt, ether, or ester, of 1592U89 or HIV protease inhibitor(s); or any other compound which upon administration to the recipient, is capable of providing (directly or indirectly) such a compound or an antivirally active metabolite or residue thereof. Preferred esters in accordance with the invention are independently selected from the following group: (1) carboxylic acid esters in which the non-carbonyl moiety of the carboxylic acid portion of the ester grouping is selected from straight or branched chain alkyl (for example, methyl, jn-propyl, t-butyl, or n-butyl), cycloalkyi, alkoxyalkyl (for example, methoxymethyl), aralkyl (for example, benzyl), aryloxyalkyl (for example, phenoxymethyl), aryl (for example, phenyl optionally substituted by, for example, halogen, C-_₄ alkyl, or C,_₄ alkoxy), or amino; (2) sulphonate esters, such as alkyl- or aralkylsulphonyl (for example, methanesulphonyl); (3) amino acid esters (for example, L- valyl or L-isoleucyl); and (4) phosphonate esters. In such esters, unless otherwise specified, any alkyl moiety present advantageously contains from 1 to 18 carbon atoms, particularly from 1 to 6 carbon atoms, more particularly from 1 to 4 carbon atoms. Any cycloalkyi moiety present in such esters advantageously contains from 3 to 6 carbon atoms. Any aryl moiety present in such esters advantageously comprises a phenyl group. Any reference to any of the above compounds also includes a reference to a physiologically acceptable salt thereof.

Preferred derivatives of 1592U89 are the mono-, di-, and tri-phosphate esters of (1 R, 4S)-9-[4-(hydroxymethyl)-2-cyclopenten-1 -yl]guanine (carbovir).

Examples of physiologically acceptable salts of 1592U89 or HIV protease inhibitor(s) and their physiologically acceptable derivatives include salts derived from an appropriate base, such as an alkali metal (for example, sodium), an alkaline earth (for example, magnesium), ammonium and NX₄ (wherein X is C-_₄ alkyl). Physiologically acceptable salts of an hydrogen atom or an amino group include salts of organic carboxylic acids such as acetic, lactic, tartaric, malic, isethionic, lactobionic, and succinic acids, organic sulphonic acids, such as methanesulphonic, ethanesulphonic, benzenesuiphonic and p- toluenesulphonic acids and inorganic acids, such as hydrochloric, sulphuric, phosphoric and sulphamic acids. Physiologically acceptable salts of a compound of an hydroxy group include the anion of said compound in combination with a suitable cation such as Na⁺, NH₄ ⁺ and NX₄ (wherein X is a C,_₄ alkyl group).

For therapeutic use, salts of 1592U89 or HIV protease inhibitor(s) will be physiologically acceptable, i.e. they will be salts derived from a physiologically acceptable acid or base. However, salts of acids or bases which are not physiologically acceptable may also find use, for example, in the preparation or purification of a physiologically acceptable compound. All salts, whether or not derived from a physiologically acceptable acid or base, are within the scope of the present invention.

Preferred salts of 1592U89 are the succinate salt and the hemisulphate salt.

Combinations of 1592U89 or a physiologically functional derivative thereof and HIV protease inhibitor(s) or a physiologically functional derivative thereof may hereinafter be referred to as combinations according to the invention.

The present invention further provides combinations according to the invention for use in the treatment of an HIV infection including infections with HIV mutants bearing resistance to nucleoside inhibitors, particularly zidovudine, lamivudine, ddl, ddC or d4T or combinations thereof and non-nucleoside inhibitors such as nevirapine (BI-RG-587), loviride (a-APA) and delavridine (BHAP). Furthermore, the combinations according to the invention are especially useful for the treatment of AIDS and related clinical conditions such as AIDS related complex (ARC), progressive generalized lymphadenopathy (PGL), Kaposi's sarcoma, thrombocytopenic purpura, AIDS-related neurological conditions such as AIDS dementia complex, multiple sclerosis or tropical paraperesis, and also anti-HIV antibody-positive and HIV-positive conditions, including such conditions in asymptomatic patients.

According to another aspect, the present invention provides a method for the treatment of an HIV infection in an infected animal, for example, a mammal including a human, which comprises treating said animal with a therapeutically effective amount of a combination of 1592U89, or a physiologically functional derivative thereof, and one or more HIV protease inhibitors or a physiologically functional derivative thereof.

Reference herein to treatment extends to prophylaxis as well as the treatment of established infections or symptoms.

It will be appreciated that the compounds of the combination may be administered simultaneously, either in the same or different pharmaceutical formulations or sequentially. If there is sequential administration, the delay in administering the second and any subsequent active ingredient should not be such as to lose the benefit of a synergistic therapeutic effect of the combination of the active ingredients. It will also be understood that the compounds of the combination or the physiologically functional derivatives of any thereof, whether presented simultaneously or sequentially, may be administered individually or in multiples or in any combination thereof. 1592U89 and HIV protease inhibitor(s) are preferably administered simultaneously or sequentially in separate pharmaceutical formulations, most preferably simultaneously.

The present invention also provides the use of 1592U89 in the manufacture of a medicament for administration simultaneously or sequentially with one or more HIV protease inhibitors for the treatment and/or prophylaxis of HIV infections and associated clinical conditions hereinbefore described. It will be appreciated that 1592U89 and one or more HIV protease inhibitors may be used in the manufacture of the above medicament.

The synergistic effects of the combination of 1592U89 and an HIV protease inhibitor or a physiologically functional derivative of any thereof are seen over a ratio, for example, of 1 to 10: 1 to 20 (by weight), preferably 1 to 5: 1 to 10 (by weight), particularly 1 to 2: 1 to 3 (by weight). Convenient ratios of 1592U89 to an HIV protease inhibitor include 1 :1.5, 1 :2, 1 :3, and 1 :4. Conveniently each compound may be employed in the combination in an amount at which it exhibits antiviral activity when used alone.

The amount of a combination of 1592U89 and one or more protease inhibitors required to be effective as an anti-HIV agent may, of course, vary and is ultimately at the discretion of the medical practitioner. The factors to be considered include the route of administration and nature of the formulation, the animal's body weight, age and general condition and the nature and severity of the disease to be treated.

In general, a suitable dose of an HIV protease inhibitor for administration to a human may be in the range of 5 to 100 mg per kilogram body weight per day, advantageously in the range of 8 to 70 mg per kilogram body weight per day, and preferably in the range of 8 to 50 mg per kilogram body weight per day.

In general a suitable dose of 1592U89 for administration to a human for treatment of an HIV injection may be in the range of 0.1 to 120 mg per kilogram body weight of the recipient per day, advantageously in the range of 3 to 90 mg per kilogram body weight per day and preferably in the range 5 to 60 mg per kilogram body weight per day.

Unless otherwise indicated all weights of active ingredients are calculated in terms of the drug per se. In the case of a physiologically functional derivative of 1592U89 or an HIV protease inhibitor, or a solvate of any thereof the figures would be increased proportionately. The desired dose may preferably be presented as one, two, three, four, five, six or more sub-doses administered at appropriate intervals throughout the day.

These sub-doses may be administered in unit dosage forms, for example, containing from 1 to 1500 mg, preferably from 5 to 1000 mg, most preferably from 10 to 700 mg of active ingredient per unit dosage form. Alternatively, if the condition of the recipient so requires, the dose may be administered as a continuous infusion. The components of the combination which may be referred to as active ingredients may be administered for therapy to an animal e.g. a mammal including a human in a conventional manner.

While it possible for the active ingredients of the combination to be administered as the raw chemical it is preferable to present them as a pharmaceutical formulation. Pharmaceutical formulations according to the present invention comprise a combination according to the invention together with one or more pharmaceutically acceptable carriers or excipients and optionally other therapeutic agents. The carrier(s) must be acceptable in the sense of being compatible with the other ingredients of the formula and not deleterious to the recipient thereof. When the individual components of the combination are administered separately they are generally each presented as a pharmaceutical formulation. The references hereinafter to formulations refer unless otherwise stated to formulations containing either the combination or a component thereof.

A combination of 1592U89 and one or more HIV protease inhibitors, or a physiologically functional derivative of any thereof may conveniently be presented as a pharmaceutical formulation in a unitary dosage form. A convenient unitary dosage formulation contains the active ingredients in amounts of from 50 mg to 3 g each, for example, 100 mg to 2 g.

It is also possible to combine any two of the active ingredients in a unitary dosage form for simultaneous or sequential administration with the third active ingredient, for example, a typical unitary dosage may contain 50 mg to 3 g each of 1592U89 and one or more HIV protease inhibitors, advantageously 100 mg to 2 g each of 1592U89 and one or more HIV protease inhibitors.

A further feature of the present invention is a unitary dosage form comprising at least two active ingredients selected from 1592U89 and one or more HIV protease inhibitors or physiologically functional derivatives of any thereof and a pharmaceutically acceptable carrier therefor.

Pharmaceutical formulations are often prescribed to the patient in "patient packs" containing the whole course of treatment in a single package, usually a blister pack.

Patient packs have an advantage over traditional prescriptions, where a pharmacist divides a patient's supply of a pharmaceutical from a bulk supply, in that the patient always has access to the package insert contained in the patient pack, normally missing in traditional prescriptions. The inclusion of a package insert has been shown to improve patient compliance with the physician's instructions and, therefore, lead generally to more successful treatment.

It will be understood that the administration of the combination of the invention by means of a single patient pack, or patient packs of each formulation, containing within a package insert instructing the patient to the correct use of the invention is a desirable additional feature of this invention.

According to a further aspect of the invention provided is a multiple, for example, double or triple, pack comprising at least one active ingredient 1592U89 and one or more HIV protease inhibitors of the combination of the invention and an information insert containing directions on the use of the combination of the invention.

According to another aspect the invention provides a patient pack comprising in association for separate administration 1592U89 or a physiologically functional derivative thereof together with at least one HIV protease inhibitor or a physiologically functional derivative thereof.

Formulations include those suitable for oral, rectal, nasal, topical (including transdermal, buccal and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous and intradermal) administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. Such methods represent a further feature of the present invention and include the step of bringing into association the active ingredients with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active ingredients with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product.

Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, caplets, cachets or tablets each containing a predetermined amount of the active ingredients; as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste.

A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredients in a free-flowing form such as a powder or granules, optionally mixed with a binder (e.g. povidone, gelatin, hydroxypropyl methyl cellulose), lubricant, inert diluent, preservative, disintegrant (e.g. sodium starch glycollate, cross-linked povidone, cross-linked sodium carboxymethyl cellulose) surface-active or dispersing agent. Molded tablets may be made by molding a mixture of the powdered compound moistened with an inert liquid diluent in a suitable machine. The tablets may optionally be coated or scored any may be formulated so as to provide slow or controlled release of the active ingredients therein using, for example, hydroxypropyl methyl cellulose in varying proportions to provide the desired release profile. Tablets may optionally be provided with an enteric coating, to provide release in parts of the gut other than the stomach.

Formulations suitable for topical administration in the mouth include lozenges comprising the active ingredients in a flavored base, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active ingredient in a suitable liquid carrier. Formulations for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter or a salicylate.

Topical administration may also be by means of a transdermal iontophoretic device.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such carriers as are known in the art to be appropriate.

Pharmaceutical formulations suitable for rectal administration wherein the carrier is a solid are most preferably presented as unit dose suppositories. Suitable carriers include cocoa butter and other materials commonly used in the art. The suppositories may be conveniently formed by admixture of the active combination with the softened or melted carrier(s) followed by chilling and shaping in molds.

Formulations suitable for parenteral administration include aqueous and nonaqueous isotonic sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents; and liposomes or other microparticulate systems which are designed to target the compound to blood components or one or more organs. The formulations may be presented in unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injection, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described. Preferred unit dosage formulations are those containing a daily dose or daily subdose of the active ingredients, as hereinbefore recited, or an appropriate fraction thereof.

It should be understood that in addition to the ingredients particularly mentioned above the formulations of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example, those suitable for oral administration may include such further agents as sweeteners, thickeners and flavoring agents.

The compounds of the combination of the present invention may be obtained in a conventional manner.

1592U89 may be prepared by the method described in European Specification EP0434450, PCT application PCT/GB/4500225, PCT/GB95/02014, U.S. Patent No. 5,034,394, or GB9709945.1 which are incorporated herein by reference.

HIV protease inhibitors may be prepared by any method known to persons skilled in the art, for examples those methods disclosed in WO 94/05639, WO 95/24385, WO 94/13629, WO 92/16501 , WO 95/16688, W0/US94/13085, W0/US94/12562, US 93/59038, EP 541 168, WO 94/14436, WO 95/09843, WO 95/32185, WO 94/15906, WO 94/15608, WO

94/04492, WO 92/08701 , WO 95/32185, and U.S. Patent No. 5,256,783, incorporated herein by reference hereto.

The following examples are intended for illustration only and are not intended to limit the scope of the invention in any way. "Active ingredient" denotes 1592U89 and an HIV protease inhibitor or multiples thereof or a physiologically functional derivative of any of the aforementioned compounds. Example 1 :

Safety and Antiviral Effect of 1592U89 in Combination with Nucleoside Reverse

Transcriptase Inhibitors and Protease Inhibitors

Design: Nine HIV infected subjects previously treated with 1592U89 with or without zidovudine in a 12 week dose selection study were eligible. Patients had been required to stop 1592U89 treatment for varying periods of time until additional pre-clinical data was available. 1592U89 (300 mg twice daily) was added to treatments containing (zidovudine or lamivudine) + (indinavir or ritonavir). Virologic and immunologic responses were assessed by HIV-RNA polymerase chain reaction (PCR), HIV-DNA PCR, and CD4+ cell counts.

Results: Eight patients completed 24 weeks combination treatment since restarting 1592U89. The most common adverse events (AE) were diarrhoea and nausea, which resolved either spontaneously or upon therapy change. No serious AEs were observed.

Weeks of therapy 0 4 8 12 24

HIV RNA PCR (log-ocopies/ml) 4.54 (9) 2.60 (9) 2.60 (8) 2.60 (8) 2.60 (8)

HIV DNA PCR (copies/10⁵ cells) 132 (8) not tested not tested not tested 15 (8) CD4+ cells x 10⁵/L 315 (9) 314 (9) 314 (9) 517 (7) 489 (8)

Conclusions: Combination therapy with 1592U89 + (zidovudine or 3TC) + (indinavir or ritonavir) was generally well tolerated. All treatment combinations reduced viral load to undetectable levels from as early as week 4 and this effect was sustained through week 24. Corresponding CD4+ cell count rises were also observed. These results indicated the potential intensification of antiviral effects with 1592U89 treatment in patients taking other nucleoside reverse transcriptase inhibitors and protease inhibitors. Example 2: Tablet Formulation

The following formulations A, B and C are prepared by wet granulation of the ingredients with a solution of povidone, followed by addition of magnesium stearate and compression.

Formulation A mg/tablet

Active Ingredient 250

Lactose B.P. 210

Povidone B.P. 15

Sodium Starch Glycollate 20 Magnesium Stearate 5

500

Formulation B mq/tablet

Active Ingredient 250

Lactose B.P. 150

Avicel PH 101 60 Povidone B.P. 15

Sodium Starch Glycollate 20

Magnesium Stearate 5

500 Formulation C mg/tablet

Active Ingredient 250

Lactose B.P. 200

Starch 50

Povidone 5

Magnesium Stearate 4

359

The following formulations, D and E, are prepared by direct compression of the admixed ingredients. The lactose in formulation E is of the direct compression type (Dairy Crest- "Zeparox").

Formulation D mg/tablet Active Ingredient 250

Pregelatinized Starch NF15 150

400

Formulation E mg/tablet Active Ingredient 250

Lactose B.P. 150

Avicel 100

500 Formulation F (Controlled Release Formulation)

The formulation is prepared by wet granulation of the ingredients with a solution of povidone followed by the addition of magnesium stearate and compression.

mg/tablet

Active Ingredient 500

Hydroxypropylmethylcellulose 1 12

(Methocel K4M Premium)

Lactose B.P. 53

Povidone B.P. 28

Magnesium Stearate 7

700

Drug release takes place over a period of about 6-8 hours and is complete after 12 hours.

Example 3: Capsule Formulations

Formulation A

A capsule formulation is prepared by admixing the ingredients of formulation D in Example 2 above and filling into a two-part hard gelatin capsule. Formulation B (infra) is prepared in a similar manner. Formulation B mg/capsule

Active Ingredient 250

Lactose B.P. 143

Sodium Starch Glycollate 25

Magnesium Stearate 2

420

Formulation C mg/capsule

Active Ingredient 250

Macrogel 4000 B.P. 350

600

Capsules of formulation C are prepared by melting the Macrogel 4000 B.P., dispersing the active ingredient in the melt and filling the melt into a two-part hard gelatin capsule.

Formulation D mg/capsule

Active Ingredient 250

Lecithin 100

Arachis Oil 100

450 Capsules of formulation D are prepared by dispersing the active ingredient in the lecithin and arachis oil and filling the dispersion into soft, elastic gelatin capsules.

Formulation E mg/capsule

Active Ingredient 150.0

Vitamin E TPGS 400.0

Polyethylene Glycol 400 NF 200.5

Propylene Glycol USP 39.5

Four (4) kilograms (kg) of Vitamin E TPGS (obtained from Eastman Chemical Co.) was heated at 50°C until liquefied. To the liquified Vitamin E TPGS, 2.005 kg of polyethylene glycol 400 (PEG400) (low aldehyde, <10 ppm, obtained from Union Carbide or Dow

Chemical Co.) heated to 50 C was added and mixed until a homogeneous solution was formed. The resultant solution was heated to 65 C. 1.5 kg of active ingredient was dissolved in the liquefied solution of Vitamin E TPGS and PEG 400. 0.395 kg of propylene glycol at room temperature was added and mixed until a homogenous solution was formed. The solution was cooled to 28-35 C. The solution was then de-gassed. The mixture was preferably encapsulated at 28-35 C at a fill weight equivalent to 150 mg of volatiles-free compound, into Size 12 oblong, white opaque soft gelatin capsules using a capsule filling machine. The capsule shells were dried to a constant fill moisture of 3-6% water and a shell hardness of 7-10 newtons, and placed in a suitable container.

Formulation F (Controlled Release Capsule)

The following controlled release capsule formulation is prepared by extruding ingredients a,b, and c using an extruder, followed by spheronization of the extrudate and drying. The dried pellets are then coated with release-controlling membrane (d) and filled into a two-piece, hard gelatin capsule.

mg/capsule

(a) Active Ingredient 250 (b) Microcrystalline Cellulose 125

(c) Lactose B.P. 125

(d) Ethyl Cellulose 13

513

Example 4: Injectable Formulation

Formulation A ma

Active Ingredient 200 Hydro chloric Acid Solution 0.1 M or

Sodium Hydroxide Solution 0.1 M q.s. to pH 4.0 to 7.0

Sterile water q.s. to 10 ml

The active ingredient is dissolved in most of the water (35 - 40 C) and the pH adjusted to between 4.0 and 7.0 with the hydrochloric acid or the sodium hydroxide as appropriate. The batch is then made up to volume with water and filtered through a sterile micropore filter into a sterile 10 ml amber glass vial (type 1 ) and sealed with sterile closures and overseals. Formulation B

Active Ingredient 125 mg

Sterile, Pyrogen-free, pH 7 Phosphate

Buffer, q.s. to 25 ml

Example 5: Intramuscular Injection

Active Ingredient 200 mg

Benzyl Alcohol 0.10 g

Glycofurol 75 1-45 g

Water for injection q.s. to 3.00 ml

The active ingredient is dissolved in the glycofurol. The benzyl alcohol is then added and dissolved, and water added to 3 ml. The mixture is then filtered through a sterile micropore filter and sealed in sterile 3 ml amber glass vials (type 1).

Example 6: Syrup

Active Ingredient 250 mg

Sorbitol Solution 1.50 g

Glycerol 2.00 g Sodium Benzoate 0.005 g

Flavor, Peach 17.42.3169 0.0125 ml

Purified Water q.s. to 5.00 ml

The active ingredient is dissolved in a mixture of the glycerol and most of the purified water. An aqueous solution of the sodium benzoate is then added to the solution, followed by addition of the sorbital solution and finally the flavor. The volume is made up with purified water and mixed well.

Example 7: Suppository mg/capsule suppository

Active Ingredient 250

Hard Fat, B.P. (Witepsol H 15-Dynamit Nobel) 1770

2020

One-fifth of the Witepsol Hi 5 is melted in a steam-jacketed pan at 45°C maximum. The active ingredient is sifted through a 200μm sieve and added to the molten base with mixing, using a Silverson fitted with a cutting head, until a smooth dispersion is achieved. Maintaining the mixture at 45 C, the remaining Witepsol Hi 5 is added to the suspension and stirred to ensure a homogenous mix. The entire suspension is passed through a 250μm stainless steel screen and, with continuous stirring, is allowed to cool to 45° C. At a temperature of 38° C to 40° C, 2.02 g of the mixture is filled into suitable, 2 ml plastic molds. The suppositories are allowed to cool to room temperature.

Example 8: Pessaries mg/pessary

Active Ingredient 250 Anhydrate Dextrose 380

Potato Starch 363

Magnesium Stearate 7

1000 The above ingredients are mixed directly and pessaries prepared by direct compression of the resulting mixture.

The application of which this description and claims form part may be used as a basis for priority in respect of any subsequent application. The claims of such subsequent application may be directed to any feature or combination of features described herein. They may take the form of product, composition, process or use claims and may include, by way of example and without limitation, one or more of the following claims.

Claims

1. A combination comprising (-)-(l S, 4R) -4-[2-amino-6-(cyclopropylamino)-9H-purin- 9-yl]-2-cyclopentene-1 -methanol and a HIV protease inhibitor, provided that the HIV protease inhibitor is not 3S-[3R^*(l R^*,2S^*)]-[3-[[(4-aminophenyl)sulphonyl](2- methylpropyl)-amino]-2-hydroxy-1 -phenylmethyl)propyl]earbamic acid, tetrahydro-3- furanyl ester.

2. A combination comprising (-)-(l S, 4R) -4-[2-amino-6-(cyclopropylamino)-9H-purin-

9-yl]-2-cyclopentene-1 -methanol and a compound selected from indinavir, sanquinavir, ritonavir, and nelfinavir.

3. A combination comprising (-)-(lS, 4R) -4-[2-amino-6-(cyclopropylamino)-9H-purin- 9-yl]-2-cyclopentene-1 -methanol or a physiologically functional derivative thereof and nelfinavir or a physiologically functional derivative thereof.

4. A combination comprising (-)-(lS, 4R) -4-[2-amino-6-(cyclopropylamino)-9H-purin- 9-yl]-2-cyclopentene-1 -methanol or a physiologically functional derivative thereof and indinavir or a physiologically functional derivative thereof.

5. A combination comprising (-)-(lS, 4R) -4-[2-amino-6-(cyclopropylamino)-9H-purin- 9-yl]-2-cyclopentene-1 -methanol or a physiologically functional derivative thereof and ritonavir or a physiologically functional derivative thereof.

6. A combination according to any claim from 1 to 5 for use in medical therapy.

7. A pharmaceutical formulation comprising a combination according to claims 1 or 5 in association with one or more pharmaceutically acceptable carriers therefor.

8. A formulation according to claim 7 in unit dosage form.

9. A method for the treatment of an HIV infection in an infected animal which comprises treating said animal with a therapeutically effective amount of a combination as defined in any claim from 1 to 5.

10. A method according to claim 9 wherein at least two of the components of the combination are administered simultaneously.

1 1. A method according to claim 9 wherein at least two of the components of the combination are administered sequentially.

12. A method according to claim 9 wherein the combination is administered as a single combined formulation.

13. A method according to any of claims 9 to 12 wherein said animal is a human.

14. Use of (-)-(l S, 4R) -4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2- cyclopentene-1 -methanol in the manufacture of a medicament for administration either simultaneously or sequentially with one or more HIV protease inhibitors for the treatment and/or prophylaxis of an HIV infection.

15. Use according to claim 14 for ihe treatment of an HIV infection resistant to nucleoside reverse transcriptase inhibitors or non-nucleoside reverse transcriptase inhibitors.

16. Use as claimed in claims 14 or 15 in the treatment of AIDS.

17. Use as claimed in claims 14 or 15 in the treatment of AIDS related conditions or AIDS dementia complex.

18. A patient pack comprising at least one active ingredient selected from (-)-(lS,

4R) -4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclopentene-1-methanol and ritonavir, indinavir, or nelfinavir.