OA17070A - Tenofovir alafenamide hemifumarate. - Google Patents

Abstract

A hemifumaiate form of 9-[(R)-2-[[(S)-[[(S)-1(isopropoxycarbonyl)ethyl]amino]phenoxyphosphi nyl]methoxy]propyl]adenine (tenofovir alafenamide), and antiviral therapy using tenofovir alafenamide hemifurnarate (e.g., anti-HIV and anti-HBV therapies).

Description

-2SUMMARY OF THE INVENTION [0003] Described is a hemifiimarate form of9-[(R)-2-[[(S)-[[(S)-l (isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine. The name for 9-[(R)-2-[[(S)-[[(S)-l(isopropoxycarbonyl)ethyl]amino]phenoxyphosphiny1]methoxy]propyl]adenine is tenofovir alafenamide. The hemiftimarate form of tenofovir alafenamide is also referred to herein as tenofovir alafenamide hemifiimarate.

[0004] ln one embodiment ofthe invention is provided tenofovir alafenamide hemifiimarate.

|0005] ln another embodiment is provided tenofovir alafenamide hemiftimarate, wherein the ratio of fumaric acid to tenofovir alafenamide is 0.5 ± 0.1, or 0.5 ± 0.05, or 0.5 ± 0.01, or about 0.5.

[0006] ln one embodiment is provided tenofovir alafenamide hemifumarate in a solid form.

[0007] In one embodiment is provided tenofovir alafenamide hemifumarate that has an X-ray powder diffraction (XRPD) pattern having 2theta values of

6.9 ± 0.2° and 8.6 ± 0.2°. In another embodiment is provided tenofovir alafenamide hemifumarate wherein the XRPD pattern comprises 2theta values of

6.9 ± 0.2°, 8.6 ± 0.2°, 11.0 ± 0.2°, 15.9 ± 0.2°, and 20.2 ± 0.2°.

[0008] ln one embodiment is provided tenofovir alafenamide hemifumarate that has a differential scanning calorimetry (DSC) onset endotherm of 131 ± 2 °C, or 131 ± 1 °C.

[0009] In one embodiment is provided a pharmaceutical composition comprising tenofovir alafenamide hemiftimarate and a pharmaceutically acceptable excipient, ln another embodiment is provided the pharmaceutical composition, further comprising an additional therapeutic agent. In a further embodiment, the additional therapeutic agent is selected from the group consisting of human immunodeficiency virus (HIV) protease inhibiting compounds, HIV nonnucleoside inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.

-3[0010] In one embodiment is provided a method for treating a human immunodeficiency virus (HIV) infection comprising administering to a subject in need thereof a therapeutically effective amount of tenofovir alafenamide hemifumarate. In another embodiment is provided a method for treating an HIV infection comprising administering to a subject in need thereof a therapeutically effective amount of a pharmaceutical composition comprising tenofovir alafenamide hemifumarate. In a further embodiment, the method comprises administering to the subject one or more additional therapeutic agents selected from the group consisting of HIV protease inhibiting compounds, HIV nonnucleoside inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.

[0011] In one embodiment is provided a method for treating a hcpatitis B virus (HBV) infection comprising administering to a subject in need thereof a therapeutically effective amount of tenofovir alafenamide hemifumarate. In another embodiment is provided a method for treating an HBV infection comprising administering to a subject in need thereof a therapeutically effective amount ofthe pharmaceutical composition comprising tenofovir alafenamide hemifumarate.

[0012] In one embodiment is provided a method for preparing a pharmaceutical composition comprising combining tenofovir alafenamide hemifumarate and a pharmaceutically acceptable excipient to provide the pharmaceutical composition.

[0013] In one embodiment is provided a method for preparing tenofovir alafenamide hemifumarate comprising subjecting a solution comprising a suitable solvent; fumaric acid; tenofovir alafenamide; and, optionally, one or more seeds of tenofovir alafenamide hemifumarate to conditions that provide for the crystallizatïon ofthe fumaric acid and the tenofovir alafenamide. In one embodiment, the solvent comprises acetonitrile. In another embodiment, the solution is subjected to a température in the range of from about 0 °C to about 75 °C. ¢/

-4[0014] In one embodiment is provided tenofovir alafenamide hemifumarate for use in medical therapy.

10015] In one embodiment is provided the use of tenofovir alafenamide hemifumarate for the prophylactic or therapeutic treatment of an HIV infection. In another embodiment is provided the use of tenofovir alafenamide hemifumarate to treat an HIV infection. In a further embodiment is provided the use of tenofovir alafenamide hemifumarate for the préparation or manufacture of a médicament for the treatment of an HIV infection. In another further embodiment is provided tenofovir alafenamide hemifumarate for use in treating an HIV infection.

[0016] In one embodiment is provided the use oftenofovir alafenamide hemifumarate for the prophylactic or therapeutic treatment of an HBV infection. In another embodiment is provided the use of tenofovir alafenamide hemifumarate to treat an HBV infection. In a further embodiment is provided the use of tenofovir alafenamide hemifumarate for the préparation or manufacture of a médicament for the treatment of an HBV infection. In another further embodiment is provided tenofovir alafenamide hemifumarate for use in treating an HBV infection.

10017] In some embodiments ofthe invention, the methods of treating and the like comprise administration of multiple daily doses. In other embodiments, the methods of treating and the like comprise administration of a single daily dose. [0018] In one embodiment of the invention is provided a composition consisting essentially of tenofovir alafenamide hemifumarate.

BRIEF DESCRIPTIONS OFTHE DRAWINGS [0019] FIG. 1 shows the X-ray powder diffraction (XRPD) pattern oftenofovir alafenamide hemifumarate.

[0020] FIG. 2 shows a graph of the DSC analysis of tenofovir alafenamide hemifumarate.

[0021[ FIG. 3 shows a graph ofthe thermogravimetric analysis (TGA) data for tenofovir alafenamide hemifumarate. q/

-5(0022] FIG. 4 shows a graph of the dynamic vapor sorption (DVS) analysis of tenofovir alafenamide hemifumarate.

DETAILED DESCRIPTION OF THE INVENTION [0023] Spécifie values listed within the présent description for radicals, substituents, and ranges are for illustration only; they do not exclude other defined values or other values within defîned ranges for the radicals and substituents.

10024] ln one embodiment, there is provided a hemifumarate form of tenofovir alafenamide (i.e., tenofovir alafenamide hemifumarate). This form may hâve a ratio (i.e., a stoichiometric ratio or mole ratio) of fumaric acid to tenofovir alafenamide of 0.5 ± 0.1, 0.5 ± 0.05, 0.5 ± 0.01, or about 0.5, or the like.

[0025] In one embodiment, tenofovir alafenamide hemifumarate consists of fumaric acid and tenofovir alafenamide in a ratio of 0.5 iO.l, [0026] In one embodiment, tenofovir alafenamide hemifumarate consists essentially of fumaric acid and tenofovir alafenamide in a ratio of 0.5 ± 0.1. [0027] In one embodiment, tenofovir alafenamide hemifumarate has an XRPD pattern comprising 2theta values of 6.9 ± 0.2°, 8.6 ± 0.2°, 10.0 ± 0.2°, 11.0 ± 0.2°, 12.2 ± 0.2°, 15.9 ± 0.2°, 16.3 ± 0.2°, 20.2 ± 0.2°, and 20.8 ± 0.2°. [0028] In one embodiment, tenofovir alafenamide hemifumarate has an XRPD pattern comprising at least four 2theta values selected from 6.9 ± 0.2°, 8.6 ± 0.2°, 10.0 ± 0.2°, 11.0 ± 0.2°, 12.2 ± 0.2°, 15.9 ± 0.2°, 16.3 ± 0.2°, 20.2 ± 0.2°, and 20.8 ± 0.2°.

[0029] In one embodiment, tenofovir alafenamide hemifumarate has a DSC onset endotherm of 131 ± 2 °C, or 131 ± 1 °C.

[0030] In one embodiment, a tenofovir alafenamide hemifumarate composition comprises less than about 5% by weight of tenofovir alafenamide monofumarate. [0031] ln one embodiment, a tenofovir alafenamide hemifumarate composition comprises less than about 1% by weight of tenofovir alafenamide monofumarate. |0032| In one embodiment, a tenofovir alafenamide hemifumarate composition comprises less than about 0.5% by weight of tenofovir alafenamide monofumarate. rJ

-6|0033| In one embodiment, a tenofovir alafenamîde hemifumarate composition comprises no détectable tenofovir alafenamîde monofumarate.

[0034] Tenofovir alafenamîde (i.e., the compound 9-[(R)-2-[[(S)-[[(S)-l(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine) can be prepared as described in U.S. Patent No. 7,390,791.

Sélective Crystallization [0035] In one embodiment, tenofovir alafenamîde hemifumarate can be prepared using sélective crystallization. An example of a scheme for this préparation method is as follows.

NH₂

|0036| The method can be carried out by subjecting a solution comprising: a) a suitable solvent; b) fumaric acid; c) tenofovir alafenamîde; and, optionally, d) one or more seeds comprising tenofovir alafenamîde hemifumarate, to conditions that provide for the crystallization of fumaric acid and tenofovir alafenamîde. The starting solution can contain the single diastereomer of tenofovir alafenamîde or a mixture of tenofovir alafenamîde and one or more of its other diastereomers (e.g., GS-7339, as described in U.S. Patent No. 7,390,791).

[0037] The sélective crystallization can be carried out in any suitable solvent. For example, it can be carried out in a protic solvent or in an aprotic organic o

solvent, or in a mixture thereof. In one embodiment, the solvent comprises a protic solvent (e.g., water or isopropyl alcohol). In another embodiment, the solvent comprises an aprotic organic solvent (e.g., acetone, acetonitrile (ACN), toluene, ethyl acetate, isopropyl acetate, heptane, tetrahydrofuran (THF),

2-methyl THF, methyl ethyl ketone, or methyl isobutyl ketone, or a mixture thereof). In one embodiment, the solvent comprises ACN or a mixture of ACN and up to about 50% methylene chloride (by volume). The sélective crystallization also can be carried out at any suitable température, for example, a température in the range of from about 0 °C to about 70 °C. In one spécifie embodiment, the resolution is carried out at a température of about 0 °C.

[0038] One major advantage of the hemifumarate form of tenofovir alafenamide over the monofumarate form is its exceptional capability to purge GS-7339 (i.e., 9-[(R)-2-[[(R)-[[(S)-l(isopropoxyearbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine; described in, e.g., U.S. Patent No. 7,390,791), which is the major diastereomeric impurity in the active pharmaceutical ingrédient. Thus, the hemifumarate form of tenofovir alafenamide can be more readily and easily separated from impurities than the monofumarate form. Other major advantages of tenofovir alafenamide hemifumarate over the monofumarate form include improved thermodynamic and chemical stability (including long-term storage stability), superior process reproducibility, superior drug product content uniformity, and a higher melting point.

[0039] Tenofovir alafenamide hemifumarate is useful in the treatment and/or prophylaxie of one or more viral infections in man or animais, including infections caused by DNA viruses. RNA viruses, herpesviruses (e.g., CMV, HSV 1, HSV 2, VZV), retroviruses, hepadnaviruses (e.g., HBV), papillomavirus, hantavirus, adenoviruses and HIV. U.S. Patent No. 6,043,230 (incorporated by référencé herein in its entirety) and other publications describe the antiviral specificity of nucléotide analogs, such as tenofovir disoproxil. Like tenofovir disoproxil, tenofovir alafenamide is another prodrug form of tenofovir, and can be used in the treatment and/or prophylaxie ofthe same conditions.

-8[0040] Tenofovir alafenamide hemifumarate can be administered by any route appropriate to the condition to be treated. Suitable routes include oral, rectal, nasal, topical (including ocular, buccal, and sublingual), vaginal, and parentéral (including subcutaneous, intramuscular, întravenous, întradermal, intrathecal, and épidural). Generally, tenofovir alafenamide hemifumarate is administered orally, but it can be administered by any of the other routes noted herein.

[00411 Accordingly, pharmaceutical compositions include those suitable for topical or systemic administration, including oral, rectal, nasal, buccal, sublingual, vaginal, or parentéral (including subcutaneous, intramuscular, întravenous, întradermal, intrathecal, and épidural) administration. The formulations are in unit dosage form and are prepared by any of the methods well known in the art of pharmacy.

[0042] For oral therapeutic administration, the tenofovir alafenamide hemifumarate may be combined with one or more excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, élixirs, suspensions, syrups, wafers, and the like. Such pharmaceutical compositions and préparations will typically contain at least 0.1% of tenofovir alafenamide hemifumarate. The percentage of this active compound in the compositions and préparations may, of course, be varied and may conveniently be between about 2% to about 60% or more of the weight of a given unit dosage form. The amount of active compound in such therapeutically useful pharmaceutical compositions is preferably such that an effective dosage level will be obtained upon administration of a single-unit dosage (e.g., tablet). Other dosage formulations may provide therapeutically effective amounts of tenofovir alafenamide hemifumarate upon repeated administration ofsubclinically effective amounts of the same. Preferred unit dosage formulations include those containing a daily dose (e.g., a single daily dose), as well as those containing a unit daily subclinical dose, or an appropriate fraction thereof (e.g., multiple daily doses), of tenofovir alafenamide hemifumarate.

[0043] Pharmaceutical compositions suitable for oral administration may be presented as discrète units such as capsules, cachets, or tablets, each containing a predetermined amount of tenofovir alafenamide hemifumarate; as a powder or o/

-9granules; as a solution or a suspension in an aqueous liquid or a nonaqueous liquid; or as an oil-în-water liquid émulsion or a water-in-oil liquid émulsion. Tenofovir alafenamide hemifumarate may also be presented as a bolus, electuary, or paste.

[0044] Tenofovir alafenamide hemifumarate is preferably administered as part of a pharmaceutical composition or formulation, Such pharmaceutical composition or formulation comprises tenofovir alafenamide hemifumarate together with one or more pharmaceutically acceptable carriers / excipients, and optionally other therapeutic ingrédients, The excipient(s) / carrier(s) must be “acceptable” in the sense of being compatible with the other ingrédients of the formulation and not deleterious to the patient. Excipients include, but are not limited to, substances that can serve as a vehicle or medium for tenofovir alafenamide hemifumarate (e.g., a diluent carrier). They may be enclosed in hard or soft shell gelatin capsules, may be compressed into tablets, or may be incorporated directly with the food of the patient’s diet.

[0045] Accordingly, the tablets, troches, pills, capsules, and the like may also contain, without limitation, the following: a binder(s), such as hydroxypropyl cellulose, povidone, or hydroxypropyl methylcellulose; a filler(s), such as microcrystalline cellulose, pregelatinized starch, starch, mannitol, or lactose monohydrate; a disintegrating agent(s), such as croscarmellose sodium, crosslinked povidone, or sodium starch glycolate; a lubricant(s), such as magnésium stéarate, stearic acid, or other metallic stéarates; a sweetening agent(s), such as sucrose, fructose, lactose, or aspartame; and/or a flavoring agent(s), such as peppermint, oil of wintergreen, or a cherry flavoring. When the unit dosage form is a capsule, it may contain, in addition to materials of the above types, a liquid carrier, such as a vegetable oil or a polyethylene glycol. Various other materials may be présent as coatings or to otherwise modify the physical form of the solid unît dosage form. For instance, tablets, pills, or capsules may be coated with gelatin, polymers, wax, shellac, or sugar and the like. Of course, any material used in preparing any unit dosage form typically will be pharmaceutically acceptable and substantially nontoxîc in the amounts employed. ln addition, (V

- ίοtenofovir alafenamide hemifumarate may be incorporated into sustained-release préparations and devices.

[0046] For infections of the eye or other extemal (issues, e.g., mouth and skin, the pharmaceutical compositions are preferably applied as a topical ointment or cream containing tenofovir alafenamide hemifumarate in an amount of, for example, 0.01 to 10% w/w (including active ingrédient in a range between 0.1% and 5% in incréments of 0.1% w/w such as 0.6% w/w, 0.7% w/w, etc.), preferably 0.2 to 3% w/w and most preferably 0.5 to 2% w/w. When formulated in an ointment, the active ingrédient may be employed with either a paraffînic or a water-miscible ointment base. Altematively, the active ingrédient may be formulated in a cream with an oil-in-water cream base.

[0047] Pharmaceutical compositions suitable for topical administration in the mouth include lozenges comprising tenofovir alafenamide hemifumarate in a flavored basis, for example, sucrose and acacia or tragacanth; pastilles comprising the active ingrédient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active ingrédient in a suitable liquid carrier.

[0048] Formulations for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter or a salicylate.

[0049] Pharmaceutical formulations suitable for parentéral administration are stérile and include aqueous and nonaqueous injection solutions that may contain antioxidants, bufiers, bacteriostats, and solutés that render the formulation isotonie with the blood of the intended récipient; and aqueous and nonaqueous stérile suspensions that may include suspending agents and thickening agents. The formulations may be presented în unit-dose or multi-dose containers, for example, sealed ampoules and vials with elastomeric stoppers, and may be stored in a freeze-dried (lyophilized) condition rcquiring only the addition of the stérile liquid carrier (e.g., water for injections) immediately prior to use. Injection solutions and suspensions may be prepared from stérile powders, granules, and tablets ofthe kind previously described.

-11[0050] In addition to the ingrédients particularly mcntioncd above, the pharmaceutical compositions / formulations may include other ingrédients conventîonal in the art, having regard to the type of formulation in question, [0051] In another embodiment, there is provided veterinary compositions comprising tenofovir alafenamide hemifumarate together with a veterinary carrier therefor. Veterinary carriers are materials useful for the purpose of administering the composition to cats, dogs, horses, rabbits, and other animais, and may be solid, liquid, or gaseous materials that are otherwise inert or acceptable in the veterinary art and are compatible with the active ingrédient. These veterinary compositions may be adminîstered orally, parenterally, or by any other desired route.

[0052] The tenofovir alafenamide hemifumarate can be used to provide controlled release pharmaceutical formulations containing a matrix or absorbent material and an active ingrédient of the invention, in which the release of the active ingrédient can be controlled and regulated to allow less frequent dosing or to improve the pharmacokinetic or toxicity profile of the compound. Controlled release formulations adapted for oral administration, in which discrète units comprising a compounds of the invention, can be prepared according to conventîonal methods.

[0053[ Useful dosages of tenofovir alafenamide hemifumarate can be determined by comparing in vitro activities, and the in vivo activities in animal models. Methods for the extrapolation of effective amounts / dosages in mice and other animais to therapeutically effective amounts / dosages in humans are known in the art.

[0054] The amount of tenofovir alafenamide hemifumarate required for use in treatment will vary with several factors, including but not limited to the route of administration, the nature of the condition being treated, and the âge and condition of the patient; ultîmately, the amount adminîstered will be at the discrétion ofthe attendant physician or clinician. The therapeutically effective amount / dose of tenofovir alafenamide hemifumarate dépends, at least, on the nature of the condition being treated, any toxicity or drug interaction issues, whether the compound is being used prophylactically (e.g., sometimes requiring

12lower doses) or against an active disease or condition, the method of delivery, and the pharmaceutical formulation, and will be determined by the clinician using conventional dose escalation studies.

[0055] In one embodiment, the oral dose of tenofovir alafenamide hemifumarate may be in the range from about 0.0001 to about 100 mg/kg body weight per day, for example, from about 0.01 to about 10 mg/kg body weight per day, from about 0.01 to about 5 mg/kg body weight per day, from about 0.5 to about 50 mg/kg body weight per day, from about 1 to about 30 mg/kg body weight per day, from about 1.5 to about 10 mg/kg body weight per day, or from about 0.05 to about 0.5 mg/kg body weight per day. As a nonlimiting example, the daily candidate dose for an adult human of about 70 kg body weight will range from about 0.1 mg to about 1000 mg, or from about 1 mg to about 1000 mg, or from about 5 mg to about 500 mg, or from about 1 mg to about 150 mg, or from about 5 mg to about 150 mg, or from about 5 mg to about 100 mg, and may take the form of single or multiple doses.

[0056[ The pharmaceutical compositions described herein may further include one or more therapeutic agents in addition to tenofovir alafenamide hemifumarate. In one spécifie embodiment of the invention, the additional therapeutic agent can be selected from the group consisting of HIV protease inhibiting compounds, HIV nonnucleoside inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.

|0057[ Therapeutic methods include administering tenofovir alafenamide hemifumarate to a subject / patient in need of the same as a therapeutic or preventative treatment, Thus, tenofovir alafenamide hemifumarate may be administered to a subject / patient having a medical disorder or to a subject who may acquire the disorder. One of ordinary skill will appreciate that such treatment is given in order to ameliorate, prevent, delay, cure, and/or reduce the severity of a symptom or set of symptoms of a disorder (including a recurring disorder). The treatment may also be given to prolong the survival of a subject, e.g., beyond the survival time expccted in the absence of such treatment. The medical disorders that may be treated with tenofovir alafenamide hemifumarate

- 13include those discussed herein, inciuding without limitation, HIV infection and HBV infection.

[0058] The following are nonlimiting, illustrative Examples.

Example 1 [0059] Tenofovir alafenamide monofumarate solids (5.0 g) and 9-[(R)-2-[[(R)[[(S)-I(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine (GS-7339) monofumarate solids (0.75 g) were charged into 35 g MTBE at 22 °C and the mixture was stirred for I hour. A slurry was formed and was dried in a rotary evaporator. 58 g acetonitrile (ACN) was charged into the solids and the mixture was heated to reflux to dissolve the solids. The resulting solution was allowed to cool naturally while agitated. A slurry was formed, and the slurry was further cooled by ice-water-bath. The solids were isolated by filtration and washed with 5 g ACN. The solids were dried in a vacuum oven at 40 °C ovemight. 5.52 g off-white solids were obtained. The solids were analyzed by XRPD and found to contain tenofovir alafenamide monofumarate, GS-7339 monofumarate, and tenofovir alafenamide hemifumarate.

Example 2: Préparation of Tenofovir Alafenamide Hemifumarate via Sélective Crystallization [0060] 9-[(R)-2-[[[[(S)-l(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine as a slurry in ACN (9.7 kg slurry, 13.8 wt%, a diastereomeric mixture of 1.0 kg (2.10 mol, 1 mol equiv) of 9-[(R)-2-[[(S)-[[(S)-l(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine and 0.35 kgof 9-[(R)-2-[[(R)-[[(S)-l(isopropoxyearbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine was charged into a reactor and rinsed forward with dichloromethane (5 kg). The mixture was concentrated under vacuum to about 3 L with jacket température below 40 °C. The conccntrate was then coevaporatcd with ACN (6 kg) under vacuum to about 3 L with jacket température below 40 °C. The concentrate was

- 14diluted with ACN (8.5 kg) and warmed to 40-46 °C. The warm mixture was filtered into a second reactor and the filtrate was cooled to 19-25 °C.

[0061] To the above solution was charged fumaric acid (0.13 kg, 1.12 mol, 0.542 mole equiv) followed by ACN (1 kg), and the mixture was heated to 67-73 °C. The hot mixture was transferred into a reactor via a polishing filter, and then adjusted to 54-60 °C. Seed crystals (5 g) of the hemîfumarate form of tenofovir alafenamide were charged (for example, the mixture can be seeded with tenofovir alafenamide hemîfumarate formed in Example 1 or a subséquent production), and the resulting mixture was agitated at 54-60 °C for about 30 minutes. The mixture was cooled over a minimum of 4 hours to 0-6 °C, and then agitated at 0-6 °C for a minimum of 1 hour. The resulting slurry was filtered and rinsed with chilled (0-6 °C) ACN (2 kg). The product was dried under vacuum below 45 °C until loss on drying (LOD) and organic volatile impurities (OV1) limits were met (LOD < 1.0%, dichloromethane content < 0.19%, acetonitrile content < 0.19%) to afford the final compound of the hemifiimarate form of tenofovir alafenamide as a white to off-white powder (typical yield is about 0.95 kg). 'H NMR (400 MHz, d6 DMSO): 6 1.06 (d, J = 5.6 Hz, 3H), 1.12-1.16 (m, 9H), 3.77 (dd, J = 10.4, 11.6 Hz, 1 H), 3.84-3.90 (m, 2H), 3.94 (m, IH), 4.14 (dd, 6.8, 14.8 Hz, IH), 4.27 (m, IH), 4.85 (heptet, J = 6.0 Hz, IH),

5.65 (t, J = 11.2 Hz, 1 H), 6.63 (s, 1 H), 7.05 (d. J = 7.6 Hz, 2H), 7.13 (t, J = 7.2 Hz, 1 H), 7.24 (s, 2H), 7.29 (t, J = 7.6 Hz, 2H), 8.13 (t, J = 13.6 Hz, 2H), ^3IP NMR (162 MHz, d6 DMSO): δ 23.3.

Example 3: Préparation ofTenofovir Alafenamide Hemîfumarate [00621 To a jacketed reactor equipped with overhead agitator, was charged 9-[(R)-2-[[(S)-[[(S)-l(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine (10 g), fumaric acid (1.22 g), and ACN (100 mL). The mixture was heated to 70-75 °C to dissolve the solids. Any undissolved particulates were removed by filtration through a cartridge filter. The filtered solution was cooled to 60-65 °C, and seeded with 1% (by weight) of tenofovir alafenamide hemîfumarate. The slurry was aged for 30 minutes and cooled to 0-5 °C over 2 hours. The température was maintained for 1-18 hours, and the resulting slurry was filtered

- 15and washed with 2 ml of cold ACN (0-5 °C). The solids were dried under vacuum at 50 °C to provide the hemifumarate form of tenofovir alafenamide, which was characterized as described below.

Characterization of Tenofovir Alafenamide Hemifumarate from Example 3 [0063] Tenofovir alafenamide hemifumarate from Example 3 consists of 9-[(R)-

2-[[(S)-[[(S)-l(isopropoxycarbonyl)cthyl]amino]phenoxyphosphinyl]methoxy]propyl]adenïne and one-half an équivalent of fumaric acid. Tenofovir alafenamide hemifumarate is anhydrous, nonhygroscopic, and has a DSC onset endotherm of about 131 °C.

X-ray Powder Diffraction [0064] The XRPD pattern oftenofovir alafenamide hemifumarate was obtained in the following experimental setting: 45 KV, 45 mA, Καί=1.5406 A, scan range

2. - 40°, step size 0.0084°, counting time: 8.25 s. The XRPD pattern for tenofovir alafenamide hemifumarate is shown in FIG. 1. The characteristic peaks include: 6.9 ± 0.2°, 8.6 ± 0.2°, 10.0 ±0.2°, 11.0 ±0.2°, 12.2 ± 0.2°, 15.9 ± 0.2°, 16.3 ± 0.2°, 20.2 ± 0.2°, and 20.8 ± 0.2°.

Single-Crystal X-rav Diffraction [0065] The crystal size was 0.32 x 0.30 x 0.20 mm³. The sample was held at 123 K and the data was collected using a radiation source with a wavelength of 0.71073 A in the thêta range of 1.59 to 25.39°. Conditions of, and data collected from the single-crystal X-ray diffraction are shown in Table 1.

- 16Table 1. Single-Crystal X-ray Diffraction

Empirical formula	c23h3In6o7p
Formula weight	534.50
Température	123(2)K
Crystal size	0.32 x 0.30 x 0.20 mmJ
Thêta range for data collection	1.59 to 25.39°
Wavelength	0.71073 A
Crystal system	Tetragonal
Space group	P4(2)2(l)2
Unit cell dimensions	a= 18.1185(12)A a = 90° b = 18.1185(12) A β = 90° c= 17.5747(11) A γ = 90°
Volume	5769.4(6) A3
Z	8
Density (calculated)	1.231 g/cm3

PSC Analysis [0066] The DSC analysis was conducted using 2.517 mg oftenofovir alafenamide hemifumarate. It was heated at 10 °C/min over the range of40-200 °C. The onset endotherm was found to be about 131 °C (FIG. 2).

TGA Data [0067] The TGA data were obtained using 4.161 mg oftenofovir alafenamide hemifumarate. It was heated at 10 °C/min over the range of 25-200 °C. The sample lost 0.3% weight before melting (FIG. 3). It was determined to be an anhydrous form.

DVS Analysis [0068] DVS analysis was conducted using 4.951 mg oftenofovir alafenamide hemifumarate. The material was kept at 25 °C in nitrogen at humiditîes ranging from 10% to 90% relative humidity, each step was equilibrated for 120 minutes. The sorption isotherm is shown at FIG. 4. The material was found to be nonhygroscopic, and to absorb 0.65% water at a relative humidity of 90%,

- 17Purging of Diastereomeric Impurity [0069] In the prior synthèses oftenofovir alafenamide, one ofthe major impurities is typically the diastereomer 9-[(R)-2-[[(R)-[[(S)-l(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]propyl]adenine.

The hemifumarate form of tenofovir alafenamide from Example 3 has an exceptional capability to purge this diastereomeric impurity, as compared with the capability of the monofumarate form (described in U.S. Patent

No. 7,390,791). The data in Table 2 (below) demonstrates that tenofovir alafenamide hemifumarate (Batch 2) purged the diastereomeric impurity to less than one-tenth of the starting concentration, whereas the monofumarate form of tenofovir alafenamide (Batch 1) only slîghtly purged the diastereomeric impurity.

Table 2. Purging Capability Comparaison

Batch	Diastereomeric Impurity in Starting Material	Solvent	Fumaric acid charge (mole équivalent)	Product obtained	Diastereomeric Impurity in Product
1	9.3%	ACN	0.9	Monofumarate form	7.6%
2	10.0%	ACN	0.5	Hemifumarate form	0.65%

Chemical Stability |0070] Chemical stability of the hemifumarate form of tenofovir alafenamide was compared with the monofumarate form. As shown in Table 3 (below), under identical conditions, the hemifumarate form of tenofovir alafenamide was chemically more stable and exhibited better long-term storage stability, with significantly less dégradation (% Total Deg. Products) than the monofumarate form. Conditions evaluated include température, relative humidity (RH), and the open or closed state of the container cap. q/

-18Table 3. Chemical Stability Comparison

Storage Condition	Time Points (weeks)	Monofumarate form	Hemifumarate form
%TA* Area Normalized	% Total Deg. Products	%TA Area Normalized	% Total Deg. Products
40°C / 75% RH Cap Closed	0	97.1	0.69	98.4	0.05
1	97.0	0.87	98.4	0.14
2	96.6	1.18	98.5	0.14
4	96.4	1.49	98.4	0.25
8	95.4	2.36	98.0	0.49
40°C / 75% RH Cap Open	0	97.1	0.69	98.4	0.05
1	96.9	0.90	98.5	0.15
2	96.6	1.10	98.5	0.14
4	96.2	1.67	98.4	0.26
8	95.0	2.74	98.1	0.50
70°C Cap Closed	0	97.1	0.69	98.4	0.05
2	96.2	1.83	98.5	0.22
4	93.3	4.78	98.4	0.33

TA is tenofovir alafenamide

Thermodynamic Stability [0071] Stable form screening oftenofovir alafenamide hemifumarate showed that it is thermodynamically stable in most solvents, such as ACN, toluene, ethyl acetate, methyl ferr-butyl ether (MTBE), acetone, THF, and 2-methy! THF. A similar stable form screening of the monofumarate form showed that this form is not thermodynamically stable in the above-listed solvents. When suspended in these solvents, the monofumarate form of tenofovir alafenamide fully converts to the hemifumarate form in THF and 2-methyl THF, and partially converts to the hemifumarate form in ACN, ethyl acetate, MTBE, and acetone, as well as at ambient températures.

Thermal Stability [0072] As shown by the DSC data, the hemifumarate form oftenofovir alafenamide has a melting point that is about 10 °C higher than that of the monofumarate form, indicating that the hemifumarate form has improved thermal stability as compared with the monofumarate form. ¢(

- 19[00731 ΑΠ publications, patents, and patent documents are incorporated by reference herein, as though indivldually incorporated by reference. The invention has been described with reference to various spécifie and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention, A

Claims (60)

1. -20WHAT IS CLAIMED IS: (AMENDED CLAIMS)

   1. Tenofovir alafenamîde hemifumarate.
2. 2. A composition comprising tenofovir alafenamîde hemifumarate, wherein the ratio of fumaric acid to tenofovir alafenamîde in said composition is 0.5 ± 0.1.
3. 3. The composition of claim 2, wherein the ratio of fumaric acid to tenofovir alafenamîde is 0.5 ± 0.05.
4. 4. The composition of claim 2, wherein the ratio of fumaric acid to tenofovir alafenamîde is 0.5 ± 0.01.
5. 5. The composition of claim 2, wherein the ratio of fumaric acid to tenofovir alafenamîde is about 0.5.
6. 6. The hemifumarate of claim 1 that is a solid.
7. 7. The composition of claim 2 that is a solid.
8. 8. Tenofovir alafenamîde hemifumarate, having an X-ray powder diffraction pattern that comprises 2theta values of 6.9 ± 0.2° and 8.6 ± 0.2°.
9. 9. The hemifumarate of claim8, wherein the X-ray powder diffraction pattern comprises 2theta values of 6.9 ± 0.2°, 8.6 ± 0.2°, 11.0 ± 0.2°, 15.9 ± 0.2°, and 20.2 ± 0.2°.
10. 10. The hemifumarate ofclaim 1 that has a differential scanning calorimetry (DSC) onset endotherm of 131 ± 2 °C.
11. 11. The hemifumarate of claim 10 that has a DSC onset endotherm of 131 ± 1

    O,
12. 12. A pharmaceutical composition comprising the hemifumarateof claim 1 and a pharmaceutically acceptable excipient.
13. 13. A pharmaceutical composition comprising the composition of claim 2 and a pharmaceutically acceptable excipient.
14. 14. The pharmaceutical composition of claim 12, further comprising an additional therapeutic agent.
15. 15. The pharmaceutical composition of claim 13, further comprising an additional therapeutic agent.
16. 16. The pharmaceutical composition of claim 14, wherein the additional therapeutic agent is selected from the group consisting of human îmmunodeficiency virus (HIV) protease inhibiting compounds, HIV nonnucleosîde inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.
17. 17. The pharmaceutical composition of claim 15, wherein the additional therapeutic agent is selected from the group consisting of human îmmunodeficiency virus (HIV) protease inhibiting compounds, HIV nonnucleosîde inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.
18. 18. A method for preparing a pharmaceutical composition comprising combining the hemifumarate of claim I and a pharmaceutically acceptable excipient to provide the pharmaceutical composition.
19. 19. A method for preparing a pharmaceutical composition comprising combining the composition of claim 2 and a pharmaceutically acceptable excipient to provide the pharmaceutical composition. zX
20. 20. A method for preparing tenofovir alafenamide hemifurnarate comprising subjectîng a solution comprising: a) a suitable solvent; b) fiimaric acid; c) tenofovir alafenamide; and d) one or more seeds of tenofovir alafenamide hemifurnarate, to conditions that provide for the crystallîzation ofthe fumaric acid and the tenofovir alafenamide.
21. 21. The method of claim 20, wherein the solvent comprises acetonitrile.
22. 22. The method of claim 20, wherein the solution is subicctcd to a température in the range of from about 0 °C to about 75 °C.
23. 23. Use ofthe hemifumarateof claim 1 for the préparation or manufacture of a médicament for the treatment of an HIV infection.
24. 24. Use of the composition of claim 2 for the préparation or manufacture of a médicament for the treatment of an HIV infection.
25. 25. The use of claim 23, wherein the médicament further comprises one or more additional therapeutic agents selected from the group consisting of HIV protease inhibiting compounds, HIV nonnucleoside inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.
26. 26. The use of claim 24, wherein the médicament further comprises one or more additional therapeutic agents selected from the group consisting of HIV protease inhibiting compounds, HIV nonnucleoside inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.
27. 27. Use of the hemifurnarate of claim 1 for the préparation or manufacture of a médicament for the treatment of an HBV infection in a human. ρζ
28. 28. Use of the composition of claim 2 for the préparation or manufacture of a médicament for the treatment of an HBV infection in a human.
29. 29. The use of claim 23, wherein the médicament is suitable for administration in multiple daily doses.
30. 30. The use of claim 23, wherein the médicament is suitable for administration in a single daily dose.
31. 31. The use of claim 27, wherein the médicament is suitable for administration in multiple daily doses.
32. 32. The use of claim 27, wherein the médicament is suitable for administration in a single daily dose.
33. 33. The use of claim 24, wherein the médicament is suitable for administration in multiple daily doses.
34. 34. The use of claim 24, wherein the médicament is suitable for administration in a single daily dose.
35. 35. The use of claim 28, wherein the médicament is suitable for administration ïn multiple daily doses.
36. 36. The use of claim 28, wherein the médicament is suitable for administration in a single daily dose.
37. 37. A composition consisting essentially oftenofovir alafenamide hemifumarate.
38. 38. A composition consisting essentially of tenofovir alafenamide hemifumarate, wherein the ratio of fumaric acid to tenofovir alafenamide is 0.5 ± 0.1.
39. 39. The composition of claim 38, wherein the ratio of fumaric acid to tenofovir alafenamide is 0.5 ± 0.05.
40. 40. The composition of claim 38, wherein the ratio of fumaric acid to tenofovir alafenamide is 0.5 ±0.01.
41. 41. The composition of claim 38, wherein the ratio of fumaric acid to tenofovir alafenamide is about 0.5.
42. 42. The composition of claim37that is a solid.
43. 43. A composition consisting essentially of tenofovir alafenamide hemiftimarate, having an X-ray powder diffraction pattern that comprises 2theta values of 6.9 ± 0.2° and 8.6 ± 0.2°.
44. 44. The composition of claim 43, wherein the X-ray powder diffraction pattern comprises 2theta values of 6.9 ± 0.2°, 8.6 ± 0.2°, 11.0 ± 0.2°, 15.9 ± 0.2°, and 20.2 ± 0.2°.
45. 45. The composition of claim 37 that has a DSC onset endotherm of 131 ±2

    O|
46. 46. The composition of claim 45 that has a DSC onset endotherm of 131±1
47. 47. A pharmaceutical composition comprising the composition of claim37 and a pharmaceutically acceptable excipient.
48. 48. The pharmaceutical composition of claim 47, further comprising an additional therapeutic agent.
49. 49. The pharmaceutical composition of claim 48, wherein the additional therapeutic agent is selected from the group consisting of HIV protease inhibiting '

    -25compounds, HIV nonnucleoside inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.
50. 50. A method for preparing a pharmaceutical composition comprising combining the composition of claim 37 and a pharmaceutically acceptable excipient to provide the pharmaceutical composition.
51. 51. Use of the composition of claim 37 for the préparation or manufacture of a médicament for the treatment of an HIV infection.
52. 52. The use of claim 51, wherein the médicament further comprises one or more additional therapeutic agents selected from the group consisting of HIV protease inhibiting compounds, HIV nonnucleoside inhibitors of reverse transcriptase, HIV nucleoside inhibitors of reverse transcriptase, HIV nucléotide inhibitors of reverse transcriptase, HIV integrase inhibitors, and CCR5 inhibitors.
53. 53. Use of the composition of claim 37 for the préparation or manufacture of a médicament for the treatment of an HBV infection in a human.
54. 54. The use of claim 51, wherein the médicament is suitable for administration in multiple daily doses.
55. 55. The use of claim 51, wherein the médicament is suitable for administration in a single daily dose.
56. 56. The use of claim 53, wherein the médicament is suitable for administration in multiple daily doses.
57. 57. The use of claim 53, wherein the médicament is suitable for administration in a single daily dose. d
58. 58. A method for preparing tenofovir alafenamide hemifumarate comprising the steps of:

    admixing a) aprotic organic solvent; b) fumaric acid; c) tenofovir alafenamide; and d) one or more seeds of tenofovir alafenamide hemifumarate; and crystallizing additional tenofovir alafenamide hemifumaratej
59. 59. A method for preparing tenofovir alafenamide hemifumarate comprising the steps of:

    admixing a) a solvent comprising water, isopropyl alcohol, acetone, acetonitrile, toluene, ethyl acetate, isopropyl acetate, heptane, tetrahydrofuran, 2methyl tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone or mixtures thereof; b) fumaric acid; c) tenofovir alafenamide; and d) one or more seeds of tenofovir alafenamide hemifumarate; and crystallizing additional tenofovir alafenamide hemifumarate at a température from about 0 °C to about 70 °C.
60. 60. The method of claim 59, wherein the solvent comprises acetonitrile and up to about 50% by volume methylene chloride. o/

    Intensity (counts)