WO2025215403A1

WO2025215403A1 - Preparation of crystalline form 2 inupadenant hydrochloride

Info

Publication number: WO2025215403A1
Application number: PCT/IB2024/053563
Authority: WO
Inventors: Didier Schils; Arjun TUMMALA; David Booth
Original assignee: Iteos Belgium SA
Current assignee: Iteos Belgium SA
Priority date: 2024-04-11
Filing date: 2024-04-11
Publication date: 2025-10-16
Anticipated expiration: 2026-10-11

Abstract

The present disclosure relates to an improved process of preparing crystalline Form 2 inupadenant hydrochloride. In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride does not result in the preparation of crystalline Form 1 inupadenant hydrochloride. In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride. In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a suitable solvent system with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

Description

PREPARATION OF CRYSTALLINE FORM 2

INUPADENANT HYDROCHLORIDE DESCRIPTION

FIELD

[001] The present disclosure relates to an improved process of preparing crystalline Form 2 inupadenant hydrochloride. In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride does not result in the preparation of crystalline Form 1 inupadenant hydrochloride. In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride. In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a suitable solvent system with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

BACKGROUND AND SUMMARY

[002] Inupadenant is a known A2A inhibitor, useful in restoring immune functions in tumor environment. See, e.g., WO 2018/178338. Inupadenant may also be referred to as EOS-850, EOS100850, (S)-5-amino-3-(2-(4-(2,4-difluoro-5-(2- (methylsulfinyl)ethoxy)phenyl)piperazin-l-yl)ethyl)-8-(furan-2-yl)thiazolo[5,4- e][l,2,4]triazolo[l,5-c]pyrimidin-2(3H)-one, or (+)-(S)-5-amino-3-(2-(4-(2,4-difluoro-5-(2- methylsulfinyl)ethoxy)phenyl)piperazin-l-yl)ethyl)-8-(furan-2-yl)thiazolo[5,4- e][l,2,4]triazolo[l,5-c]pyrimidin-2(3H)-one. Inupadenant may also be represented as a compound of formula (la) or formula (lb), whose structures are equivalent:

[003] Inupadenant disclosed in WO 2018/178338 is a free base. However, salts are often more desirable than free bases or free acids for drug delivery and manufacturing, and amorphous forms are generally more unstable than crystalline forms. Thus, Applicant undertook significant studies to generate salts and crystalline forms of inupadenant. Eventually, crystalline Form 2 inupadenant hydrochloride was discovered and was selected for further development. See, e.g., WO 2023/059817. However, the initial process to obtain crystalline Form 2 inupadenant hydrochloride required first the production of crystalline Form 1 inupadenant hydrochloride. For example, in Example 3 of WO 2023/059817, isolated crystalline Form 1 inupadenant hydrochloride (from Example 2) was used as a starting material. The process described eventually led to crystalline Form 2 inupadenant hydrochloride. Similarly, in Example 4 of WO 2023/059817, inupadenant (free base) is combined with DMSO and hydrochloric acid to generate crystalline Form 1 inupadenant hydrochloride (called “crude HC1 salt”), which is then converted into crystalline Form 2 inupadenant hydrochloride via a slurry-to-slurry conversion in ethanol and water.

[004] Thus, in one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process does not result in the preparation of crystalline Form 1 inupadenant hydrochloride.

[005] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride.

[006] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a suitable solvent system with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

[007] In one aspect, a process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a solvent system chosen from DMSO and water, acetic acid, THF, and DMSO and THF with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, is provided.

[008] The processes disclosed herein result in direct preparation of crystalline Form 2 inupadenant hydrochloride from the free base.

BRIEF DESCRIPTION OF THE DRAWINGS

[009] Figure 1 shows XRPD patterns of intermediate materials obtained from different points during the preparation of crystalline Form 2 inupadenant hydrochloride described in Example 3. DESCRIPTION OF THE EMBODIMENTS

I. Definitions

[0010] Unless otherwise defined, all terms of art, notations and other scientific terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this disclosure pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a difference over what is generally understood in the art. The techniques and procedures described or referenced herein are generally well understood and commonly employed using conventional methodologies by those skilled in the art. Standard techniques may be used for preparation and analysis of solid forms. As appropriate, procedures involving the use of commercially available kits and reagents are generally carried out in accordance with manufacturer-defined protocols and conditions unless otherwise noted.

[0011] Unless otherwise indicated, the following terms have the following meanings:

[0012] As used herein, the singular forms “a,” “an,” and “the” include the plural referents unless the context clearly indicates otherwise. The terms “include,” “such as,” and the like are intended to convey inclusion without limitation, unless otherwise specifically indicated.

[0013] As used herein, the term “comprising” also specifically includes embodiments “consisting of and “consisting essentially of’ the recited elements, unless specifically indicated otherwise.

[0014] At various places in the present disclosure, variables or parameters are disclosed in groups or ranges. It is specifically intended that the description include each and every individual subcombination of the members of such groups and ranges. For example, an integer in the range of 0 to 10 is specifically intended to individually disclose 0, 1, 2, 3, 4, 5,

6, 7, 8, 9, and 10.

[0015] The use of any and all examples, or exemplary language herein, for example “such as” or “including” is intended to merely illustrate better the present disclosure and does not pose a limitation on the scope of the disclosure.

[0016] As used herein, the term “suitable solvent system” refers to one or more solvents that, when used in a process of preparing crystalline Form 2 hydrochloride, results in crystalline Form 2 inupadenant hydrochloride where there is no observable crystalline Form 1 inupadenant hydrochloride. By “no observable crystalline Form 1 inupadenant hydrochloride” what is meant is that no crystalline Form 1 inupadenant hydrochloride is observed to either the limit of detection or, in some embodiments, the limit of quantification, using commercially available analytical techniques such as with commercially available x-ray powder diffractometers. As such, DMSO alone is not a suitable solvent system as it has been shown that this can result in the formation of observable crystalline Form 1 inupadenant hydrochloride. See WO 2023/059817 at Examples 2 and 3. In some embodiments, the suitable solvent system is DMSO and water, or DMSO, 2-propanol, and water. In many embodiments, the suitable solvent system is DMSO and water.

[0017] As used herein, ranges and amounts can be expressed as “about” a particular value or range. About also includes the exact amount. Hence “about 0 °C” means “about 0 °C” and also “0 °C.” Generally, the term “about” includes an amount that one skilled in the art would expect to be within experimental error, such as for example, the experimental error could be within 15%, 10%, or 5% of the recited value depending on the measurement.

[0018] Crystalline Form 1 inupadenant hydrochloride and crystalline Form 2 inupadenant hydrochloride can be identified by any technique known to those skilled in the art, including those set forth in WO 2023/059817, which is incorporated herein by reference. II. Process of Preparation

[0019] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process does not result in the preparation of crystalline Form 1 inupadenant hydrochloride. Thus, in some embodiments, crystalline Form 1 inupadenant hydrochloride is not observed to be present to the limit of detection of typical analytical methods, such as x-ray powder diffraction using a standard commercially available diffractometer, during the preparation of crystalline Form 2 inupadenant hydrochloride. In some embodiments, crystalline Form 1 inupadenant hydrochloride is not observed to be present to the limit of quantification of typical analytical methods, such as x-ray powder diffraction using a standard commercially available diffractometer, during the preparation of crystalline Form 2 inupadenant hydrochloride. For example, in some embodiments, crystalline Form 1 inupadenant hydrochloride as an intermediate in the preparation of crystalline Form 2 inupadenant hydrochloride, either by itself or as a mixture with another crystalline form such as crystalline Form 2 inupadenant hydrochloride.

[0020] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride. Thus, in some embodiments, the process does not produce, at any point, an amount of a crystalline inupadenant hydrochloride in a form other than crystalline Form 2 inupadenant hydrochloride that can be observed to the limit of detection of typical analytical methods, such as x-ray powder diffraction using a standard commercially available diffractometer. In some embodiments, the process does not produce, at any point, an amount of a crystalline inupadenant hydrochloride in a form other than crystalline Form 2 inupadenant hydrochloride that can be observed to be present to the limit of quantification of typical analytical methods, such as x-ray powder diffraction using a standard commercially available diffractometer.

[0021] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a suitable solvent system with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

[0022] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a solvent system chosen from DMSO and water, acetic acid, THF, and DMSO and THF, with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

[0023] In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a solvent system as described herein with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein the hydrochloric acid is added after the inupadenant is combined with the solvent system.

[0024] In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a solvent system as described herein with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein the solvent system is DMSO and water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 80 to about 95 parts by volume DMSO to about 5 to about 30 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 80 to about 90 parts by volume DMSO to about 10 to about 30 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 80 to about 90 parts by volume DMSO to about 10 to about 25 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 80 to about 90 parts by volume DMSO to about 10 to about 20 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 80 to about 90 parts by volume DMSO to about 10 to about 15 parts by volume water.

[0025] In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 85 to about 90 parts by volume DMSO to about 10 to about 15 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 85 to about 90 parts by volume DMSO to about 10 to about 30 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 85 to about 90 parts by volume DMSO to about 10 to about 25 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 85 to about 90 parts by volume DMSO to about 10 to about 20 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 85 to about 90 parts by volume DMSO to about 10 to about 15 parts by volume water.

[0026] In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 88 to about 89 parts by volume DMSO to about 11 to about 12 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is about 89 parts by volume DMSO to about 11 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is about 88 parts by volume DMSO to about 11 parts by volume water. In some embodiments, the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is about 88 parts by volume DMSO to about 12 parts by volume water.

[0027] In many embodiments, the volume percentage of water in the final solution post hydrochloric acid addition is at least about 5%, such as about 5%, about 10%, or about 15%, at temperatures greater than room temperature such as between about 50°C and about 60°C. In many embodiments, the volume percentage of water in the final solution post hydrochloric acid addition is at least about 10% at temperatures greater than room temperature such as between about 50°C and about 60°C. In these and other embodiments, the solvent system is a suitable solvent system and may include DMSO, water, and one or more of THF, ethanol, and 2-propanol.

[0028] In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a solvent system as described herein with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein the hydrochloric acid is added in from about 1.0 to about 1.5 molar equivalents compared to inupadenant. In some embodiments, hydrochloric acid is added in about 1.0 molar equivalents compared to inupadenant.

[0029] In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a solvent system as described herein with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein the combination of inupadenant and the solvent system is heated before addition of the hydrochloric acid. In some embodiments, the combination of inupadenant and the solvent system is brought to a temperature of from about 40 °C to about 50 °C, optionally with stirring, before addition of the hydrochloric acid. In some embodiments, the temperature is from about 40 °C to about 45 °C, before addition of the hydrochloric acid. In some embodiments, the temperature is about 42 °C, before addition of the hydrochloric acid.

[0030] In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a solvent system as described herein with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein combination of inupadenant, solvent system, and hydrochloric acid is heated. In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is brought to a temperature of from about 50 °C to about 70 °C, optionally with stirring. In some embodiments, the temperature is from about 55 °C to about 65 °C. In some embodiments, the temperature is from about 60 °C to about 65 °C. In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is stirred at said temperature for a period of time. In some embodiments, the period of time is from about 15 minutes to about 1 hour. In some embodiments, the period of time is from about 15 minutes to about 45 minutes. In some embodiments, the period of time is about 30 minutes.

[0031] In some embodiments, the process of preparing crystalline Form 2 inupadenant hydrochloride comprises combining inupadenant in a solvent system as described herein, with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein combination of inupadenant, solvent system, and hydrochloric acid is filtered. In some embodiments, the combination is filtered after the combination is heated. In some embodiments, the filtration is vacuum filtration. In some embodiments, the filtration is done by filter membrane, such as microfiber filter membrane. In some embodiments, the filtration is vacuum filtration using glass microfiber (GMF) filter membrane. In some embodiments, the filter (such as a filter membrane) is washed with a solvent (such as DMSO or DMSO and water). [0032] In some embodiments, the concentration of inupadenant hydrochloride in the combination of inupadenant, solvent system, and hydrochloric acid is from about 75 mg/mL to about 150 mg/mL. In some embodiments, the concentration of inupadenant hydrochloride is from about 80 mg/mL to about 115 mg/mL. In some embodiments, the concentration of inupadenant hydrochloride is from about 85 mg/mL to about 105 mg/mL. In some embodiments, the concentration of inupadenant hydrochloride is from about 85 mg/mL to about 100 mg/mL. In some embodiments, the concentration of inupadenant hydrochloride is from about 80 mg/mL to about 100 mg/mL. In some embodiments, the concentration of inupadenant hydrochloride is from about 85 mg/mL to about 95 mg/mL. In some embodiments, said concentration (such as from about 85 mg/mL to about 95 mg/mL) is the concentration of the solution after filtration. In these and other embodiments, the concentration of inupadenant hydrochloride is measured at temperatures of greater than about 50 °C, such as at about 60 °C.

[0033] In some embodiments, the concentration of inupadenant hydrochloride in solution was found to be about 100 mg/mL in a solution that was about 89% by volume DMSO and about 11% by volume water at about 60 °C. In these and other embodiments, at concentrations of greater than about 120 mg/mL at about 60 °C, self-nucleation was observed in some experiments resulting in crystalline Form 1 inupadenant hydrochloride and/or mixtures of crystalline Form 1 inupadenant hydrochloride and crystalline Form 2 inupadenant hydrochloride.

[0034] In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is cooled. In some embodiments, the combination of inupadenant, solvent, and hydrochloric acid is brought to a temperature of from about 50 °C to about 60 °C. In some embodiments, the temperature is from about 55 °C to about 60 °C. In some embodiments, the temperature is about 55 °C. [0035] In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is seeded with crystalline Form 2 inupadenant hydrochloride. In some embodiments, the combination is filtered prior to being seeded with crystalline Form 2 inupadenant hydrochloride. In some embodiments, the combination is cooled prior to seeding. The crystalline Form 2 inupadenant hydrochloride used for seeding may be made, for example, following the teachings of WO 2023/059817.

[0036] In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is seeded with crystalline Form 2 inupadenant hydrochloride at a temperature of from about 50 °C to about 60 °C. In some embodiments, the combination is seeded at a temperature of from about 55 °C to about 60 °C. In some embodiments, the combination is seeded at a temperature of about 55 °C.

[0037] In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is heated, then filtered, and then cooled. In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is heated, then filtered, then cooled, and then seeded with crystalline Form 2 inupadenant hydrochloride.

[0038] In some embodiments, the combination of inupadenant, solvent system, and hydrochloric acid is stirred for a period of time after seeding with crystalline Form 2 inupadenant hydrochloride. In some embodiments, the combination is stirred at a temperature of from about 50 °C to about 60 °C. In some embodiments, the combination is cooled to about 55 °C to about 60 °C. In some embodiments, the combination is cooled to about 55 °C. In some embodiments, the combination is stirred from about 30 minutes to about 3 hours. In some embodiments, the combination is stirred from about 1 hour to about 2 hours.

[0039] In some embodiments, an antisolvent is added to the combination of inupadenant, solvent system, and hydrochloric acid. In some embodiments, the antisolvent is added before seeding with crystalline Form 2 inupadenant hydrochloride. In some embodiments, the antisolvent is added after seeding with crystalline Form 2 inupadenant hydrochloride. In some embodiments, the antisolvent is added simultaneously with the seeds.

[0040] In some embodiments, the antisolvent is added over a period of time. In some embodiments, the antisolvent is added over a period of from about 30 minutes to about 6 hours. In some embodiments, the antisolvent is added over a period of from about 30 minutes to about 5 hours. In some embodiments, the antisolvent is added over a period of from about 30 minutes to about 4 hours. In some embodiments, the antisolvent is added over a period of from about 30 minutes to about 3 hours. In some embodiments, the antisolvent is added over a period of from about 30 minutes to about 2 hours. In some embodiments, the antisolvent is added over a period of from about 30 minutes to about 1 hour.

[0041] In some embodiments, the antisolvent is chosen from water, 2-propanol, or a combination thereof. In some embodiments, the antisolvent is water. In some embodiments, the antisolvent is a combination of water and 2-propanol.

[0042] In some embodiments, the combination of inupadenant, solvent system, hydrochloric acid, and antisolvent is cooled.

[0043] In some embodiments, the combination of inupadenant, solvent system, hydrochloric acid, and antisolvent is brought to a temperature of from about 0 °C to about 10 °C. In some embodiments, the combination is brought to a temperature of from about 0 °C to about 5 °C. In some embodiments, the combination is maintained, optionally with stirring, at this temperature for a period of time. In some embodiments, the period of time is from about 1 hour to about 15 hours. In some embodiments, the period of time is from about 1 hour to about 5 hours. In some embodiments, the period of time is from about 1 hour to about 2 hours. [0044] In some embodiments where DMSO is part of the suitable solvent system and the antisolvent is water, residual DMSO is observed in dried solids after crystallization. It has been observed that sometimes DMSO content is higher than 20,000 ppm when the water antisolvent is added at temperatures of less than or equal to about 25°C. In some embodiments, when the suitable solvent system comprises DMSO:water in a volume ratio of about 89% to about 11% respectively, the concentration of inupadenant hydrochloride at between about 25 °C and about 50 °C has been measured to be less than about 50 mg/mL. In such embodiments, therefore, antisolvent addition, such as from water, is typically carried out at higher temperature, such as above 50 °C to mitigate DMSO entrapment.

[0045] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a solvent system comprising DMSO and water, and hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein the resulting ratio of DMSO to water (volume/volume) is from about 40 to about 50 parts by volume DMSO to about 50 to about 60 parts by volume water. In some embodiments, the resulting ratio of DMSO to water (volume/volume) is from about 40 to about 45 parts by volume DMSO to about 55 to about 60 parts by volume water.

[0046] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a solvent system as described herein with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein the process does not result in the preparation of crystalline Form 1 inupadenant hydrochloride.

[0047] In one aspect, the present disclosure relates to a process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a solvent system as described herein with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas, and wherein the process results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride.

ENUMERATED EMBODIMENTS

[0048] Embodiment 1. A process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process does not result in the preparation of crystalline Form 1 inupadenant hydrochloride.

[0049] Embodiment 2. A process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride.

[0050] Embodiment 3. A process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a suitable solvent system with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

[0051] Embodiment 4. A process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a solvent system chosen from DMSO and water, acetic acid, THF, and DMSO and THF with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

[0052] Embodiment 5. The process of Embodiments 3 or 4, wherein the hydrochloric acid is added after the inupadenant is combined with the solvent system.

[0053] Embodiment 6. The process of any one of claims 3-5, wherein the solvent system is DMSO and water.

[0054] Embodiment 7. The process of Embodiment 6, wherein the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 80 to about 90 parts by volume DMSO to about 10 to about 15 parts by volume water. [0055] Embodiment 8. The process of any one of Embodiments 3-7, wherein the hydrochloric acid is added in from about 1.0 to about 1.5 molar equivalents compared to inupadenant.

[0056] Embodiment 9. The process of any one of Embodiments 3-8, wherein the combination of inupadenant and a solvent system is heated before addition of the hydrochloric acid.

[0057] Embodiment 10. The process of any one of Embodiments 3-8, wherein the combination of inupadenant and a solvent system is brought to a temperature of from about 40 °C to about 50 °C, optionally with stirring, before addition of the hydrochloric acid.

[0058] Embodiment 11. The process of any one of Embodiments 3-10, wherein the combination of inupadenant, a solvent system, and hydrochloric acid is heated.

[0059] Embodiment 12. The process of any one of Embodiments 3-10, wherein the combination of inupadenant, solvent system, and hydrochloric acid is brought to a temperature of from about 50 °C to about 70 °C, optionally with stirring.

[0060] Embodiment 13. The process of any one of Embodiments 3-10, wherein the combination of inupadenant, solvent system, and hydrochloric acid is filtered.

[0061] Embodiment 14. The process of any one of Embodiments 3-13, wherein the concentration of inupadenant hydrochloride in the combination of inupadenant, solvent system, and hydrochloric acid is from about 75 mg/mL to about 150 mg/mL.

[0062] Embodiment 15. The process of Embodiment 14, wherein the concentration of inupadenant hydrochloride in the combination of inupadenant in a solvent system and hydrochloric acid is from about 85 mg/mL to about 95 mg/mL.

[0063] Embodiment 16. The process of any one of Embodiments 3-15, wherein the combination of inupadenant, solvent system, and hydrochloric acid is seeded with crystalline Form 2 inupadenant hydrochloride. [0064] Embodiment 17. The process of Embodiment 16, wherein the combination of inupadenant, solvent system, and hydrochloric acid is cooled prior to seeding.

[0065] Embodiment 18. The process of Embodiment 16, wherein the combination of inupadenant, solvent system, and hydrochloric acid is brought to a temperature of about 50 °C to about 60 °C.

[0066] Embodiment 19. The process of any one of Embodiments 3-18, wherein an antisolvent is added to the combination of inupadenant, solvent system, and hydrochloric acid.

[0067] Embodiment 20. The process of Embodiment 19, wherein the antisolvent is chosen from water, 2-propanol, or a combination thereof.

[0068] Embodiment 21. The process of Embodiment 20, wherein the antisolvent is water.

[0069] Embodiment 22. The process of any one of Embodiments 19-21, wherein the combination of inupadenant, solvent system, hydrochloric acid, and antisolvent is cooled.

[0070] Embodiment 23. The process of any one of Embodiments 19-21, wherein the combination of inupadenant, solvent system, hydrochloric acid, and antisolvent is brought to a temperature of from about 0 °C to about 10 °C.

[0071] Embodiment 24. The process of any one of Embodiments 6-23, wherein the resulting ratio of DMSO to water (volume/volume) is from about 40 to about 50 parts by volume DMSO to about 50 to about 60 parts by volume water.

[0072] Embodiment 25. The process of any one of Embodiments 3-24, wherein the process does not result in the preparation of crystalline Form 1 inupadenant hydrochloride. [0073] Embodiment 26. The process of any one of Embodiments 3-24, wherein the process results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride.

EXAMPLES

Abbreviations and Definitions

Example 1. Analytical Methods

[0074] XPRD - XRPD analysis was carried out on a PANalytical X’pert pro with PIXcel detector (128 channels), scanning the samples between 3 and 35° 29. The material was gently ground to release any agglomerates and loaded onto a multi-well plate with Kapton or Mylar polymer film to support the sample. The multi-well plate was then placed into the diffractometer and analyzed using Cu K radiation (al X = 1.54060 A; a2 = 1.54443 A; P = 1.39225 A; al : a2 ratio = 0.5) running in transmission mode (step size 0.0130° 29, step time 18.87s) using 40 kV / 40 mA generator settings. Data were visualized and images generated using the HighScore Plus 5.2 desktop application (Malvern PANalytical B.V,

2023).

[0075] HPLC-UV - Purity was measured by HPLC-UV using the following parameters:

[0076] HPLC-CAD - HPLC-CAD was measured as described below:

[0077] KF - Average moisture content was measured using the following method.

Approximately 20 mg of solid was weighed into a 10 mL glass vial and tightly sealed with a screw cap. Samples were analyzed using an InMotion KFOven Autosampler at 150 °C. Samples were analyzed in duplicate and an average moisture content reported. See parameters below. Example 2. Preparation of crystalline Form 2 inupadenant hydrochloride using

DMSO/water or DMSO/water/2-propanol

[0078] A series of experiments were undertaken to find an improved process of preparing crystalline Form 2 inupadenant hydrochloride. As described below in more detail, crystalline Form 2 inupadenant hydrochloride may be prepared from inupadenant (free base) and hydrochloric acid using a suitable solvent system such as DMSO and water or DMSO, 2- propanol, and water. Inupadenant (free base) can be prepared according to WO 2018/178338, for example. Additional water or a mixture of 2-propanol and water may be used to facilitate crystallization of inupadenant hydrochloride.

[0079] In many embodiments, seeds of crystalline Form 2 inupadenant hydrochloride are added to a clear filtered solution at elevated temperatures after the addition of the hydrochloric acid. In many embodiments, inupadenent hydrochloride is prepared at concentrations low enough to preclude solids forming prior to the addition of crystalline Form 2 inupadenant hydrochloride seeds. Mixtures of crystalline Form 1 inupadenant hydrochloride and crystalline Form 2 inupadenant hydrochloride that may crystallize upon cooling may be converted to substantially crystalline Form 2 inupadenant hydrochloride by prolonged slurring of the solids at elevated, ambient, or sub-ambient temperatures. In some embodiments, the solids may be collected by vacuum filtration and washed with 2-propanol or t-BME prior to vacuum oven drying.

[0080] These examples are discussed in more detail below and also summarized in Table 1. Exemplary XRPD patterns of crystalline Form 1 inupadenant hydrochloride and crystalline Form 2 inupadenant hydrochloride can be found in WO 2023/059817 - see, e.g., Figures 4, 5, 12, and 21-23.

[0081] Trial 1. Inupadenant (3 g) was placed in a reactor and combined with 24.3 mL of DMSO and 2.7 mL of water. The contents were stirred at 25 °C and 200 RPM. The mixture was heated to 42 °C and 0.435 mL (1.05 mol equiv.) of 37% aqueous hydrochloric acid was added. The solids were observed to have dissolved, and the mixture was stirred for an additional 15 minutes. The solution was then heated to 62 °C and held at this temperature with stirring for an additional 15 minutes. The solution was filtered at this temperature into a clean reactor through a 0.45 pm GMF membrane, and the membrane was washed with 3.0 mL of a 9: 1 DMSO: water solution which was added to the filtered solution. The reaction mixture was then cooled with stirring at 200 rpm to 55 °C. Crystalline Form 2 inupadenant hydrochloride seeds (62 mg) were then added to the mixture which facilitated nucleation and growth of crystals. The contents were stirred for an additional hour at 55 °C then 27 mL of 2-propanol was slowly added to the reaction mixture over a period of 9 hours. Stirring continued for an additional 4 hours after the addition of 2-propanol was complete after which time the reaction mixture was cooled 25 °C at a rate of 0.1 °C/min. The reaction mass was held at this temperature for an additional hour with stirring. The slurry was then transferred to another reactor and 87 mL of an 86: 16 mixture of 2-propanol: water was added at a rate of 0.1 mL/min. The reaction mixture was then stirred for an additional 6 hours at 25 °C after the addition was complete. The slurry was then heated to 60 °C at 0.2 °C/min and stirred at this temperature for 6 hours. The reaction was then cooled to 3 °C at 0.1 °C/min and stirred at this temperature for approximately 26 hours. The solids were isolated by vacuum filtration and vacuum dried at 45 °C for 2 days. XRPD analysis provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride.

[0082] Trial 2. Inupadenant (4 g) was placed in a vial and combined with 14.4 mL of DMSO and 1.6 mL of water at 25 °C with stirring. The contents were heated to 42 °C and 0.58 mL (1.05 mol equiv.) of 37% hydrochloric acid was added which facilitated dissolution of the solids. [0083] The solution was stirred at 42 °C for 10 minutes then heated to 62 °C and stirred at this temperature for 45 minutes. Crystallization was visually observed to have taken place at this temperature. The mass was transferred into a 100 mL vessel and a solution of 3.6 mL DMSO and 0.4 mL water was added. The reaction mass was heated to 75 °C with stirring and then held at this temperature for 15 minutes, solids remained undissolved under these conditions. The experiment was then cooled to 60 °C and stirring was continued for one hour at this temperature. XRPD analysis of a small portion of the solids indicated the presence of crystalline Form 1 inupadenant hydrochloride. Stirring was continued an additional 2 hours at 60 °C, then 76.6 mL of a mixture of 2-propanol: water (89.5: 10.5 %v/v) was added to the reaction at a rate of 0.1 mL/min. The reaction mass was then stirred for approximately 2 hours after the addition was complete. The material then cooled to 3 °C at 0.1 °C/min and stirring continued for 4 hours at 3 °C. The solids were isolated by vacuum filtration and washed with 16 mL of 2-propanol. The solids were dried under vacuum at 45 °C for approximately 72 hours. XRPD analysis provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride.

[0084] Trial 3. Inupadenant (5 g) was placed in a vial and combined with 18 mL of DMSO and 2.0 mL of water at 25 °C with stirring. The contents were heated to 42 °C and 0.725 mL (1.05 mol equiv.) of 37% hydrochloric acid was added which facilitated dissolution of the solids.

[0085] The solution was stirred at 42 °C for 10 minutes, then heated to 62 °C and stirred at this temperature for 45 minutes. Crystallization was visually observed to have taken place at this temperature. The mass was transferred the mass into a 100 mL vessel and a solution of 4.5 mL DMSO and 0.5 mL water was added. The slurry was stirred for 1 hour at 60 °C. XRPD analysis of a small portion of the solids indicated the presence of crystalline Form 1 inupadenant hydrochloride. Stirring was continued an additional 2 hours at 60 °C, then 19.5 mL of water was added to the reaction at a rate of 0.05 mL/min. The reaction was stirred for an additional 2 hours at 60 °C and then cooled to 3 °C at 0.1 °C/min. The contents were stirred for an additional 8 hours at this temperature. XRPD analysis of a small portion of the solids indicated the presence of crystalline Form 1 inupadenant hydrochloride. The reaction mass was then heated to 60 °C at 1 °C/min. stirring for an additional 2 hours at this temperature. XRPD analysis of a small portion of the solids indicated the presence of crystalline Form 1 inupadenant hydrochloride. The experiment was then cooled to 3 °C at 0.1 °C/min and then stirred for an additional 8 hours at 3 °C. The solids were isolated by vacuum filtration and washed with 10 mL of 2-propanol. The solids were dried under vacuum at 45 °C for approximately 72 hours. XRPD analysis provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride.

[0086] Trial 4. Inupadenant (3 g) was placed in a reactor and combined with 18.9 mL of DMSO and 2.1 mL of water. The contents were stirred at 25 °C and 200 RPM. The mixture was heated to 42 °C and 0.435 mL (1.05 mol equiv.) of 37% hydrochloric acid was added. The solids were observed to have dissolved, and the mixture was stirred for an additional 10 minutes. The solution was then heated to 62 °C and held at this temperature with stirring for an additional 30 minutes. The solution was filtered at this temperature into a clean reactor through a 0.45 pm GMF membrane, and the membrane was washed with 1.5 mL of a 9: 1 DMSO: water solution which was added to the filtered solution. The reaction mixture was then stirred at 62 °C while crystalline Form 2 inupadenant hydrochloride seeds (30 mg) were added to the mixture, which facilitated nucleation and growth of crystals. The contents were stirred for 2 hours at 62 °C. XRPD analysis of a portion of the solids at this time provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride. The reaction was stirred for an additional 2 hours at 60 °C and then 82.5 mL of a mixture of 2- propanol: water (89: 11) was added at a rate of 0.1 mL/min. Stirring was continued for an additional 2 hours at 60 °C once the addition was complete. The reaction was then cooled to

3 °C at a rate of 0.1 °C/min. The reactor was held at this temperature for an additional 15 hours with stirring. The solids were then isolated by vacuum filtration and vacuum dried at 45 °C for 24 hours. XRPD analysis provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride.

[0087] Trial 5. Inupadenant (3 g) was placed in a reactor and combined with 25.6 mL of DMSO and 2.8 mL of water. The contents were stirred at 25 °C and 200 RPM. The mixture was heated to 42 °C and 0.435 mL (1.05 mol equiv.) of 37% hydrochloric acid was added. The solids were observed to have dissolved, and the mixture was stirred for an additional 10 minutes. The solution was then heated to 62 °C and held at this temperature with stirring for an additional 10 minutes. The solution was filtered at this temperature into a clean reactor through a 0.45 pm GMF membrane, and the membrane was washed with 3.0 mL of a 9: 1 DMSO: water solution which was added to the filtered solution. The reaction mixture was then stirred at 58 °C while crystalline Form 2 inupadenant hydrochloride seeds (30 mg) were then added to the mixture, which facilitated nucleation and growth of crystals. The contents were stirred for 2 hours at 55 °C. XRPD analysis of a portion of the solids at this time provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride. The reaction was stirred for an additional 4 hours at 55 °C, then cooled to 3 °C at a rate of 0.1 °C/min. Stirring was continued for an additional two hours at this temperature. A small portion of the solids was analyzed by XRPD which provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride. The reaction was stirred for an additional 2 hours at 3 °C then 43.5 mL of a 2 -propanol: water mixture (9: 1 v/v) was added to the reaction at a rate of 0.1 ml/min. Stirring was continued for 14 hours at 3 °C after the addition was complete. The solids were then isolated by vacuum filtration and sequentially washed with 10 mL of 2-propanol and 10 mL of t-BME. The solids were then dried under vacuum at 45 °C for 24 hours. XRPD analysis provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride.

[0088] Trial 6. Inupadenant (3 g) was placed in a reactor and combined with 18.9 mL of DMSO and 2.1 mL of water. The contents were stirred at 25 °C and 200 RPM. The mixture was heated to 42 °C and 0.435 mL (1.05 mol equiv.) 37% hydrochloric acid was added. The solids were observed to have dissolved, and the mixture was stirred for an additional 10 minutes. The solution was then heated to 60 °C and held at this temperature with stirring for an additional 15 minutes. The solution was filtered into a clean pre-heated reactor through a 0.45 pm GMF membrane, and the membrane was washed with 1.5 mL of a 9: 1 DMSO: water solution which was added to the filtered solution. The reaction mixture was then stirred at 60 °C. Crystallization was visually observed to have taken place while the reaction was stirred at this temperature. The reaction was stirred at 250 rpm and 26 mg of crystalline Form 2 inupadenant hydrochloride seed crystals were added to the reactor, which facilitated additional solids formation. The contents were stirred for an additional 6 hours at 60 °C then cooled to 3 °C and held at this temperature with stirring for 2 hours. Then 31 mL of a mixture of 2-propanol: water mixture (9: 1 v/v) were added at a rate of 0.15 mL/min. The reaction was stirred for an additional 4 hours after addition was complete. XRPD analysis of a portion of the solids provided a pattern corresponding to a mixture of crystalline Form 1 inupadenant hydrochloride and crystalline Form 2 inupadenant hydrochloride. The reactor temperature was increased to 55 °C at a rate of 0.1 °C/min and stirred for 6 hours at this temperature prior to cooling to 3 °C at a rate of 0.1 °C/min. The reaction was then held at this temperature with stirring for an additional 48 hours. The solids were isolated by vacuum filtration and sequentially washed with 6-mL portions of 2-propanol and t-BME. The solids were then dried under vacuum at 50 °C for 72 hours. XRPD analysis provided a pattern corresponding to crystalline Form 2 inupadenant hydrochloride. Table 1. Summary of trials for preparing of crystalline Form 2 inupadenant hydrochloride using DMSO/water or DMSO/water/2-propanol

* Before after polish filtration Example 3. Preparation of crystalline Form 2 inupadenant hydrochloride

(DMSO/water system)

[0089] A 2-liter reactor was charged with 150 g of inupadenant (free base), 1575 mL of dimethylsulfoxide (DMSO) and 165 mL of water. (DMSO:water ratio = 91 :9 v/v.) The suspension was heated to 42 °C with stirring (300 rpm), and then 21.75 mL 37% w/w hydrochloric acid (1.05 eq) was added. (DMSO:water ratio = 89: 11 v/v.) The material, now a clear solution, was stirred at 42 °C for 10 minutes then heated to 62 °C and stirred at this temperature for an additional 30 min. While at this temperature, the solution was vacuum filtered through GMF (glass microfiber) filter membrane into a pre-heated 5-liter reactor. The filter membrane was washed a mixture of 14.3 mL of DMSO and 0.8 mL of water which was also added to the 5-liter reactor. The concentration of inupadenant hydrochloride was measured to be 87 mg/mL. The solution was cooled under stirring (190 rpm) to 55 °C and seeded with 1.5 g of crystalline Form 2 inupadenant hydrochloride to facilitate crystallization.

[0090] Stirring was continued for an additional 2 hours at 55 °C. A total of 1911 mL of water was then added to the reactor in four portions at a rate of 5.3 mL/min: portion (1) 222 mL followed by a 1 hour hold; portion (2) 294 mL followed by a 1 hour hold; portion (3) 390 mL followed by a Ihour hold; and portion (4) 1005 mL followed by a 2 hour hold. (DMSO:water ratio = 44:56 v/v.) The contents of the reactor were then cooled to 3 °C at a rate of 0.1 °C/min and stirred at this temperature for 15 hours. A small portion of mixture was removed from the reactor, and the solids were isolated by centrifugation and determined to be crystalline Form 2 inupadenant hydrochloride by XRPD analysis (see FIG. 1).

[0091] The solids present in the reactor were separated from the slurry by vacuum filtration and the filter cake was sequentially washed with two volumes (300 mL each) of 2- propanol and t-BME. The damp solids were analyzed by XRPD and determined to be crystalline Form 2 inupadenant hydrochloride (see FIG. 1). The solids were vacuum dried at 50 °C and subsequently analyzed by XRPD which also provided an XRPD pattern corresponding to crystalline Form 2 inupadenant hydrochloride (see FIG. 1).

[0092] The dry solids were analyzed for purity by HPLC, water content by KF, and chloride content by CAD. HPLC analysis indicated a solid purity of 99.80% area. KF indicated an average moisture content of about 2.03 wt. %. And HPLC-CAD indicated about 5.3% wt. chloride.

EQUIVALENTS

[0093] The foregoing written specification is considered to be sufficient to enable one skilled in the art to practice the embodiments. The foregoing description and Examples detail certain embodiments and describe the best mode contemplated by the inventors. It will be appreciated, however, that no matter how detailed the foregoing may appear in text, the embodiment may be practiced in many ways and should be construed in accordance with the appended claims and any equivalents thereof.

[0094] As used herein, the term about refers to a numeric value, including, for example, whole numbers, fractions, and percentages, whether or not explicitly indicated. The term about generally refers to a range of numerical values (e.g., +/-5- 10% of the recited range) that one of ordinary skill in the art would consider equivalent to the recited value (e.g., having the same function or result). When terms such as at least and about precede a list of numerical values or ranges, the terms modify all of the values or ranges provided in the list. In some instances, the term about may include numerical values that are rounded to the nearest significant figure.

Claims

CLAIMS What is Claimed is:

1. A process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process does not result in the preparation of crystalline Form 1 inupadenant hydrochloride.

2. A process of preparing crystalline Form 2 inupadenant hydrochloride, wherein the process results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride.

3. A process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a suitable solvent system with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

4. A process of preparing crystalline Form 2 inupadenant hydrochloride, the process comprising combining inupadenant in a solvent system chosen from DMSO and water, acetic acid, THF, and DMSO and THF with hydrochloric acid, wherein the hydrochloric acid may be delivered in solution or by gas.

5. The process of claims 3 or 4, wherein the hydrochloric acid is added after the inupadenant is combined with the solvent system.

6. The process of any one of claims 3-5, wherein the solvent system is DMSO and water.

7. The process of claim 6, wherein the ratio of DMSO to water (volume/volume) prior to addition of the hydrochloric acid is from about 80 to about 90 parts by volume DMSO to about 10 to about 15 parts by volume water.

8. The process of any one of claims 3-7, wherein the hydrochloric acid is added in from about 1.0 to about 1.5 molar equivalents compared to inupadenant.

9. The process of any one of claims 3-8, wherein the combination of inupadenant and a solvent system is heated before addition of the hydrochloric acid.

10. The process of any one of claims 3-8, wherein the combination of inupadenant and a solvent system is brought to a temperature of from about 40 °C to about 50 °C, optionally with stirring, before addition of the hydrochloric acid.

11. The process of any one of claims 3-10, wherein the combination of inupadenant, a solvent system, and hydrochloric acid is heated.

12. The process of any one of claims 3-10, wherein the combination of inupadenant, solvent system, and hydrochloric acid is brought to a temperature of from about 50 °C to about 70 °C, optionally with stirring.

13. The process of any one of claims 3-10, wherein the combination of inupadenant, solvent system, and hydrochloric acid is filtered.

14. The process of any one of claims 3-13, wherein the concentration of inupadenant hydrochloride in the combination of inupadenant, solvent system, and hydrochloric acid is from about 75 mg/mL to about 150 mg/mL.

15. The process of claim 14, wherein the concentration of inupadenant hydrochloride in the combination of inupadenant in a solvent system and hydrochloric acid is from about 85 mg/mL to about 95 mg/mL.

16. The process of any one of claims 3-15, wherein the combination of inupadenant, solvent system, and hydrochloric acid is seeded with crystalline Form 2 inupadenant hydrochloride.

17. The process of claim 16, wherein the combination of inupadenant, solvent system, and hydrochloric acid is cooled prior to seeding.

18. The process of claim 16, wherein the combination of inupadenant, solvent system, and hydrochloric acid is brought to a temperature of about 50 °C to about 60 °C.

19. The process of any one of claims 3-18, wherein an antisolvent is added to the combination of inupadenant, solvent system, and hydrochloric acid.

20. The process of claim 19, wherein the antisolvent is chosen from water, 2-propanol, or a combination thereof.

21. The process of claim 20, wherein the antisolvent is water.

22. The process of any one of claims 19-21, wherein the combination of inupadenant, solvent system, hydrochloric acid, and antisolvent is cooled.

23. The process of any one of claims 19-21, wherein the combination of inupadenant, solvent system, hydrochloric acid, and antisolvent is brought to a temperature of from about 0 °C to about 10 °C.

24. The process of any one of claims 6-23, wherein the resulting ratio of DMSO to water (volume/volume) is from about 40 to about 50 parts by volume DMSO to about 50 to about 60 parts by volume water.

25. The process of any one of claims 3-24, wherein the process does not result in the preparation of crystalline Form 1 inupadenant hydrochloride.

26. The process of any one of claims 3-24, wherein the process results in inupadenant hydrochloride that is substantially crystalline Form 2 inupadenant hydrochloride.