Novel forms of entinostat

Abstract

To provide novel forms of entinostat.SOLUTION: The present disclosure relates to various crystalline forms of entinostat and to processes for their preparation, particularly Form A of entinostat compound with maleic acid, Form A of entinostat compound with succinic acid, Form B of entinostat compound with succinic acid, and Form C of entinostat compound with succinic acid. The present disclosure also relates to pharmaceutical compositions comprising any of these forms of entinostat and to use of these forms in preparing a medicament or in treating a disease.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present disclosure relates to various crystalline forms of entinostat and processes for their preparation. The present disclosure also relates to pharmaceutical compositions comprising any of these forms of entinostat, and to the use of these forms in the preparation of medicaments or in the treatment of diseases. [Background technology]

[0002] Entinostat, N-(2-aminophenyl)-4-[N-(pyridin-3-yl)-methoxycarbonylaminomethyl]-benzamide, is a selective, oral, once-weekly class I HDAC inhibitor that is being studied in multiple solid tumors in combination with hormone therapy and several approved PD-1 / PD-L1 antagonists. Entinostat has the following structure:

[0003] [ka]

[0004] U.S. Patent Nos. 7,973,166 and RE45,499 disclose various polymorphs of entinostat, including Form A, Form B, Form C, and an amorphous form. WO 2017 / 081278 discloses further polymorphs of entinostat, specifically Form D and Form E, as well as processes for preparing Form A. WO 2017 / 216761 discloses further crystalline forms of entinostat, stable amorphous forms, amorphous solid dispersions of entinostat, and processes for their preparation.

[0005] US Patent Application Publication No. 2020 / 0270213 discloses various co-crystals or salts of entinostat, including co-crystals or salts of entinostat with fumaric acid, succinic acid, maleic acid, and adipic acid. The entinostat and maleic acid compounds are described as having X-ray powder diffraction peaks measured using Cu-Kα radiation at 2θ values ​​of 9.8°±0.2°, 15.9°±0.2°, 19.7°±0.2°, 23.2°±0.2°, 14.1°±0.2°, 14.8°±0.2°, 17.7°±0.2°, 18.9°±0.2°, 14.5°±0.2°, 21.4°±0.2°, 23.8°±0.2°, and 24.8°±0.2°. Entinostat and the succinic acid compound are described as having X-ray powder diffraction peaks measured using Cu-Kα radiation at 2θ values ​​of 3.7°±0.2°, 7.3°±0.2°, 9.2°±0.2°, 9.5°±0.2°, 16.6°±0.2°, 17.2°±0.2°, 17.8°±0.2°, 18.5°±0.2°, 19.0°±0.2°, 20.4°±0.2°, 20.8°±0.2° and 24.6°±0.2°.

[0006] None of these references disclose entinostat co-crystals or salts formed with maleic acid having peaks at 18.6° and 18.1°±0.2° 2θ. Additionally, none of these references disclose entinostat co-crystals or salts formed with succinic acid having any of the following: peaks at 18.7° and 18.3°±0.2° 2θ; two or more peaks selected from 21.5°, 26.5°, 23.9°, and 21.7°±0.2° 2θ; or two or more peaks selected from 4.0°, 8.0°, 15.7°, and 19.0°±0.2° 2θ. Summary of the Invention

[0007] The present invention is directed to various crystalline forms of entinostat, namely, an entinostat co-crystal or salt formed with maleic acid, referred to as Form A of the entinostat compound with maleic acid, and three different polymorphs of an entinostat co-crystal or salt formed with succinic acid, namely, Form A of the entinostat compound with succinic acid, Form B of the entinostat compound with succinic acid, and Form C of the entinostat compound with succinic acid. The present invention is further directed to processes for the preparation of these forms. The present invention is also directed to pharmaceutical compositions comprising one or more of these forms, and their use in the preparation of medicaments or in the treatment of diseases. [Brief description of the drawings]

[0008] [Figure 1] 1 provides a representative XRPD pattern of Form A of the entinostat compound with maleic acid. [Diagram 2] 1 provides a representative 1H NMR of Form A of the entinostat compound with maleic acid. [Diagram 3] 1 provides a representative overlay of TGA and DSC plots of Form A of the entinostat compound with maleic acid. [Figure 4] 1 provides a representative XRPD pattern of Form A of the entinostat compound with succinic acid. [Diagram 5] 1 provides a representative 1H NMR of Form A of entinostat compound with succinic acid. [Figure 6] 1 provides a representative overlay of TGA and DSC plots of Form A of the entinostat compound with succinic acid. [Figure 7] 1 provides a representative GVS kinetic plot of Form A of the entinostat compound with succinic acid. [Figure 8] 1 provides a representative GVS isotherm plot of Form A of the entinostat compound with succinic acid. [Figure 9]1 provides a representative XRPD pattern of Form B of the entinostat compound with succinic acid. [Figure 10] 1 provides a representative 1H NMR of Form B of entinostat compound with succinic acid. [Figure 11] 1 provides a representative overlay of TGA and DSC plots of Form B of entinostat compound with succinic acid. [Figure 12] 1 provides a representative XRPD pattern of Form C of the entinostat compound with succinic acid. [Figure 13] 1 provides a representative 1H NMR of Form C of entinostat compound with succinic acid. [Figure 14] 1 provides a representative overlay of TGA and DSC plots of Form C of the entinostat compound with succinic acid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following description is presented to enable those skilled in the art to make and use the various embodiments. Descriptions of specific devices, techniques, and applications are presented only as examples. Various modifications to the examples described herein will be readily apparent to those skilled in the art, and the general principles described herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments. Thus, the various embodiments are not intended to be limited to the examples described and shown herein, but should be accorded the scope consistent with the claims.

[0010] Terms / Definitions As used herein, unless otherwise specified, the terms "about" and "approximately," when used in connection with a numerical value or range of values ​​provided to characterize a particular solid form, such as, for example, a particular temperature or range of temperatures describing a DSC or TGA thermal event, including, for example, a melting, dehydration, desolvation, or glass transition event; a mass change, such as, for example, a mass change as a function of temperature or humidity; a solvent or moisture content, for example, in terms of mass or percentage; or a peak position, such as, for example, in an analysis by IR spectroscopy or Raman spectroscopy or XRPD; indicates that the value or range of values ​​may deviate to an extent that would be considered reasonable by one of ordinary skill in the art while still describing the particular solid form.

[0011] As used herein, unless otherwise specified, the term "pharmaceutical composition" is intended to encompass a pharma- ceutical effective amount of one or more of entinostat compound Form A with maleic acid, entinostat compound Form A with succinic acid, entinostat compound Form B with succinic acid, and entinostat compound Form C with succinic acid, and a pharma- ceutical acceptable excipient. As used herein, the term "pharmaceutical composition" includes pharmaceutical compositions such as tablets, pills, powders, liquids, suspensions, emulsions, granules, capsules, suppositories, or injectable formulations.

[0012] As used herein, unless otherwise specified, the term "crystalline" and related terms, when used to describe a compound, substance, modification, material, component, or product, means that the compound, substance, modification, material, component, or product is substantially crystalline as determined by X-ray diffraction, unless otherwise specified. See, e.g., Remington: The Science and Practice of Pharmacy, 21st edition, Lippincott, Williams and Wilkins, Baltimore, Md. (2005); The United States Pharmacopeia, 23rd ed., 1843-1844 (1995).

[0013] As used herein, unless otherwise specified, "cocrystal" and "cocrystal system" refer to a solid material composed of two or more distinct components in a stoichiometric ratio that interact through non-covalent interactions, which can be specifically designed using a supramolecular synthon approach. A cocrystal in which at least one of the components is entinostat and the coformer is a second pharma- ceutically acceptable compound is referred to as a pharmaceutical entinostat cocrystal with coformer.

[0014] As used herein, unless otherwise specified, "salt" refers to a substance produced by the reaction of an acid with a base. A salt consists of a positive ion (cation) of a base and a negative ion (anion) of an acid. In this disclosure, "salt" refers to compounds formed between entinostat and maleic acid and compounds formed between entinostat and succinic acid and having the properties specified herein.

[0015] As used herein, unless otherwise specified, the term "excipient" refers to a pharma- ceutically acceptable organic or inorganic carrier material. Excipients may be natural or synthetic substances blended with the active ingredient of a drug, either for the purpose of bulking up a formulation containing an effective active ingredient (and thus often referred to as "bulking agents," "fillers," or "diluents"), or to impart a therapeutic enhancement to the active ingredient in the final dosage form, such as promoting drug absorption or solubility. Excipients may also be useful in the manufacturing process to aid in the handling of the active, such as by promoting powder flow or non-adherent properties, in addition to aiding in in vitro stability, such as preventing degradation over the expected shelf life.

[0016] As used herein, unless otherwise specified, the term "patient" refers to an animal, preferably a mammal, most preferably a human, who is the object of treatment, observation, or experiment. Preferably, the patient is experiencing and / or exhibiting at least one symptom of the disease or disorder being treated and / or prevented. In addition, the patient may not exhibit any symptoms of the disorder, disease, or condition being treated and / or prevented, but is considered by a physician, clinician, or other medical professional to be at risk for developing the disorder, disease, or condition.

[0017] As used herein, the term "polymorph", "polymorphic form" or related terms refer to a crystalline form of an API (active pharmaceutical ingredient) free base or salt thereof that can exist in two or more forms as a result of different arrangements or conformations of the molecule, ions of a salt, or within the crystal lattice of the crystalline form upon addition and processing of solvents or coformers.

[0018] As used herein, and unless otherwise specified, the terms "substantially" or "substantially free / pure" with respect to a crystalline form means that the form contains less than about 30%, less than about 20%, less than about 15%, less than about 10%, less than about 5%, or less than about 1% by weight of impurities, which may include, for example, other polymorphic forms, water, and solvents other than those in the polymorphic form.

[0019] As used herein, unless otherwise specified, the terms "treat", "treating" and "treatment" refer to the eradication or amelioration of a disease or disorder, or the eradication or amelioration of one or more symptoms associated with a disease or disorder. In certain embodiments, these terms refer to minimizing the spread or worsening of a disease or disorder resulting from the administration of one or more therapeutic agents to a patient having such a disease or disorder. In some embodiments, these terms refer to the administration of a compound provided herein, with or without other additional active agents, after the onset of symptoms of a particular disease. Entinostat has been studied in combination with hormone therapy for the treatment of breast cancer. Other studies have shown that entinostat in combination with immune checkpoint therapy may be most effective in "inflammatory" tumors such as NSCLC and melanoma, where immune checkpoint therapy has previously been attempted but disease has progressed despite this.

[0020] As used herein, unless otherwise specified, the term "room temperature" refers to ambient or working laboratory temperature range, from about 18°C ​​to about 25°C.

[0021] As used herein, unless otherwise specified, the term "atmospheric pressure" refers to approximately 760 mmHg.

[0022] It is therefore an object of the present disclosure to provide substantially pure, stable and scalable entinostat compound Form A with maleic acid, entinostat compound Form A with succinic acid, entinostat compound Form B with succinic acid, and entinostat compound Form C with succinic acid. It is also an object of the present disclosure to provide entinostat compound Form A with maleic acid, entinostat compound Form A with succinic acid, entinostat compound Form B with succinic acid, and entinostat compound Form C with succinic acid that can be isolated and handled.

[0023] Techniques for characterizing crystalline and amorphous forms include differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), gravimetric vapor sorption (GVS), X-ray powder diffractometry (XRPD), proton nuclear magnetic resonance (NMR), and NMR spectroscopy (NMR). 1 H-NMR), and solubility assessment.

[0024] XRPD XRPD diffractograms were collected on a Bruker D8 diffractometer using Cu Kα radiation (40 kV, 40 mA) and a θ-2θ goniometer fitted with a Ge monochromator. The incident beam passes through a 2.0 mm divergence slit followed by a 0.2 mm anti-scatter slit and a knife edge. The diffracted beam passes through an 8.0 mm receiving slit with a 2.5° Soller slit followed by a Lynxeye detector. The software used for data collection and analysis are Diffrac Plus XRD Commander and Diffrac Plus EVA, respectively. Samples are run at ambient conditions using as-received powder as flat plate specimens. Samples are prepared on polished zero background (510) silicon wafers by gently pressing onto a flat surface or by filling into cut cavities. The sample is rotated in its own plane. Details of the standard data collection method are as follows. Angle range: 2~42° 2θ Step size: 0.05° 2θ Acquisition time: 0.5 seconds / step (total acquisition time: 6.40 minutes)

[0025] 1 H NMR On a Bruker 400MHz instrument equipped with an autosampler and controlled by a DRX400 console or an AV3+ console with SMART probes 1 H NMR spectra were collected. Samples were prepared in DMSO-d6 solvent unless otherwise stated. Standard Bruker on-board experiments ( 1 H, 13 C{ 1 Automated experiments were acquired using the ICON-NMR configuration in Topspin software, with the NMR spectrum (H, DEPT135) and offline analysis performed using an ACD Spectrus Processor.

[0026] DSC DSC data are collected on a TA Instruments Discovery DSC equipped with a 50-position autosampler. Typically, 0.5-3 mg of each sample is heated in pinhole aluminum pans from 25 °C to 300 °C at 10 °C / min. A purge of dry nitrogen at 50 mL / min is maintained over the samples. The instrument control software is TRIOS and data are analyzed using TRIOS or Universal Analysis.

[0027] TGA TGA data are collected on a TA Instruments Discovery TGA equipped with a 25-position autosampler. Typically, 5-10 mg of each sample is loaded into a pre-weighed aluminum DSC pan and heated at 10°C / min from ambient to 350°C. A nitrogen purge at 25 ml / min is maintained over the samples. The instrument control software is TRIOS and data are analyzed using TRIOS or Universal Analysis.

[0028] GVS Sorption isotherms are obtained using a Hiden IGASorp moisture sorption analyzer controlled by Isochema HISorp software. Sample temperature is maintained at 25°C by a Grant LT ecocool 150 recirculating water bath. Humidity is controlled by mixing dry and moist nitrogen streams at a total flow rate of 250 ml / min. Relative humidity is measured by a calibrated Vaisala RH probe (operating range 0-95% RH) located near the sample. Sample weight change (mass relaxation) as a function of %RH is constantly monitored by a microbalance (accuracy ±0.001 mg). Typically, 20-30 mg of sample is placed in a tared mesh stainless steel basket under ambient conditions. Samples are loaded and unloaded at 40% RH and 25°C (typical room conditions). Moisture sorption isotherms are performed as outlined below (two scans give one complete cycle): Standard isotherms are performed at 25° C. over the range 0-90% RH at intervals of 10% RH.

[0029] [Table 1]

[0030] 4 hour solubility Sufficient sample is suspended in 1.0 ml of medium to give a maximum expected concentration of the compound in free form of approximately 10 mg / ml. The resulting suspension is then shaken at 25°C / 750 rpm for 4 hours. The pH of the sample solution is checked after 1 hour to ensure that the desired pH is maintained throughout (±0.2). After equilibration, the appearance is recorded and the final pH of the saturated solution is measured. The sample is then filtered through a glass "C" fiber filter (particle retention size 1.2 μm) before diluting with buffer as required. Quantitation is performed by HPLC with reference to a standard solution of approximately 0.15 mg / ml. Different volumes of the standard, diluted and undiluted sample solutions are injected. The solubility is calculated using the peak area, determined by integration of the peak found at the same retention time as the main peak in the standard injection.

[0031] The HPLC method for determining solubility is as follows:

[0032] [Table 2]

[0033] Analyses were performed on an Agilent HP1100 / Infinity II 1260 series system equipped with a diode array detector using OpenLAB software.

[0034] Details of the solubility medium are as follows:

[0035] [Table 3]

[0036] In one embodiment, Form A of the entinostat compound having maleic acid is prepared comprising: a) dissolving a combination of entinostat and maleic acid in methanol to form a solution; and b) cooling the solution to obtain Form A of the entinostat compound with maleic acid as a solid.

[0037] In one embodiment, the molar ratio of entinostat to maleic acid is about 1:0.5. In one embodiment, about 8-12 volumes (mL), particularly about 10 volumes, of methanol per gram of entinostat weight are used. In one embodiment, dissolution occurs at about 45-55°C, particularly about 50°C. In one embodiment, cooling is to about 0-10°C, particularly about 5°C. In one embodiment, cooling is at a rate of about 0.1°C / min. One embodiment further comprises filtering the isolated solid. A further embodiment comprises drying the isolated solid. Form A of the entinostat compound with maleic acid can be dried by any conventional method known to one of skill in the art. In one embodiment, it is dried under vacuum.

[0038] In another embodiment, Form A of the entinostat compound having maleic acid is prepared comprising: a) combining ethanol with a freeze-dried solid comprising entinostat and maleic acid to form a slurry, the molar ratio of entinostat to maleic acid being about 1:0.5; and b) aging the slurry to obtain Form A of the entinostat compound with maleic acid.

[0039] In one embodiment, the lyophilized solid comprising entinostat and maleic acid is amorphous. The volume of ethanol used is not critical as long as it is sufficient to form a slurry, but not enough to dissolve the lyophilized solid. In one embodiment, about 10 volumes (mL) of ethanol are used per gram of weight of entinostat in the lyophilized solid. In one embodiment, the aging includes temperature cycles at room temperature and about 50° C., for about 4 hours at each temperature. In one embodiment, the aging occurs for several days, for example, about 1 to 4 days, particularly about 4 days. In one embodiment, the aging results in a suspension. In one embodiment, the suspension is filtered after the aging step. In one embodiment, Form A of the entinostat compound with maleic acid is dried. Form A of the entinostat compound with maleic acid can be dried by any conventional method known to those skilled in the art. In one embodiment, the drying is under vacuum.

[0040] In one embodiment, a lyophilized solid comprising entinostat and maleic acid is prepared comprising: a) dissolving a mixture of entinostat and maleic acid in a solvent mixture of acetonitrile and water to form a solution, the molar ratio of entinostat to maleic acid being about 1:0.5; and b) freeze-drying the solution to obtain a freeze-dried solid comprising entinostat and maleic acid.

[0041] In one embodiment, the lyophilized solid comprising entinostat and maleic acid is amorphous. In one embodiment, the ratio of acetonitrile to water in the solvent mixture is about 1:1. In one embodiment, about 25-35 volumes (mL), particularly about 30 volumes, of the solvent mixture per gram of entinostat weight are used. In one embodiment, dissolving further comprises sonicating the mixture of entinostat and maleic acid in the solvent mixture. In one embodiment, lyophilization comprises freezing the solution in a dry ice / acetone bath. In a further embodiment, lyophilization comprises the use of a lyophilizer. In one embodiment, lyophilization occurs over several days, particularly over about 2 days.

[0042] In another embodiment, Form A of the entinostat compound having succinic acid is prepared comprising: a) dissolving a combination of entinostat and succinic acid in methanol to form a solution; and b) cooling the solution to obtain Form A of the entinostat compound with succinic acid as a solid.

[0043] In one embodiment, the molar ratio of entinostat to succinic acid is about 1:0.5-0.75. In one embodiment, the molar ratio of entinostat to succinic acid is about 1:0.5. In another embodiment, the molar ratio of entinostat to succinic acid is about 1:0.75. In one embodiment, about 8-12 volumes (mL), particularly about 10 volumes, of methanol are used per gram of weight of entinostat. In one embodiment, dissolution occurs at about 45-55°C, particularly about 50°C. In one embodiment, cooling is to about 0-10°C, particularly about 5°C. In one embodiment, cooling is at a rate of about 0.1°C / min. One embodiment further comprises filtering the isolated solid. A further embodiment comprises drying the isolated solid. Form A of the entinostat compound with succinic acid can be dried by any conventional method known to one of skill in the art. In one embodiment, drying is under vacuum.

[0044] In another embodiment, Form A of the entinostat compound having succinic acid is prepared comprising: a) combining a solvent selected from methanol and DMF with a freeze-dried solid comprising entinostat and succinic acid to form a slurry, wherein the molar ratio of entinostat to succinic acid is about 1:0.5; and b) aging the slurry to obtain Form A of the entinostat compound with succinic acid.

[0045] In one embodiment, the lyophilized solid comprising entinostat and succinic acid is amorphous. In one embodiment, the solvent is methanol. In another embodiment, the solvent is DMF. The volume of solvent used is not critical as long as it is sufficient to form a slurry, but not enough to dissolve the lyophilized solid. In one embodiment, about 10 volumes of solvent are used per gram of entinostat weight in the lyophilized solid. In one embodiment, the aging includes temperature cycles at room temperature and about 50° C., for about 4 hours at each temperature. In one embodiment, the aging occurs for several days, for example, about 1 to 4 days, particularly about 4 days. In one embodiment, the aging results in a solution. In a further embodiment, the solution is subjected to evaporation to obtain Form A of the entinostat compound having succinic acid. Form A of the entinostat compound having succinic acid can be dried by any conventional method known to those skilled in the art. In one embodiment, the drying is under vacuum.

[0046] In one embodiment, a lyophilized solid comprising entinostat and succinic acid is prepared comprising: a) dissolving a mixture of entinostat and succinic acid in a solvent mixture of acetonitrile and water to form a solution, the molar ratio of entinostat to succinic acid being about 1:0.5; and b) freeze-drying the solution to obtain a freeze-dried solid comprising entinostat and succinic acid.

[0047] In one embodiment, the lyophilized solid comprising entinostat and succinic acid is amorphous. In one embodiment, the ratio of acetonitrile to water in the solvent mixture is about 1:1. In one embodiment, about 55-65 volumes (mL), particularly about 60 volumes, of the solvent mixture per gram of entinostat weight are used. In one embodiment, dissolving further comprises sonicating the mixture of entinostat and succinic acid in the solvent mixture. In one embodiment, lyophilization comprises freezing the solution in a dry ice / acetone bath. In one embodiment, lyophilization comprises the use of a lyophilizer. In one embodiment, lyophilization occurs over several days, particularly over about 3 days.

[0048] In another embodiment, form B of the entinostat compound having succinic acid is prepared comprising: a) combining a solvent selected from ethyl acetate, isopropyl acetate, and methyl isobutyl ketone with a freeze-dried solid comprising entinostat and succinic acid to form a slurry, wherein the molar ratio of entinostat to succinic acid is about 1:0.5; and b) aging the slurry to obtain Form B of the entinostat compound with succinic acid.

[0049] In one embodiment, the lyophilized solid comprising entinostat and succinic acid is amorphous. In one embodiment, the solvent is ethyl acetate. In another embodiment, the solvent is isopropyl acetate. In a further embodiment, the solvent is methyl isobutyl ketone. The volume of solvent used is not critical as long as it is sufficient to form a slurry, but not enough to dissolve the lyophilized solid. In one embodiment, about 10 volumes of solvent are used per gram of entinostat weight in the lyophilized solid. In one embodiment, the aging includes temperature cycles at room temperature and about 50° C., for about 4 hours at each temperature. In one embodiment, the aging occurs for several days, for example, about 1 to 4 days, particularly about 4 days. In one embodiment, the aging results in a suspension. In one embodiment, the suspension is filtered. Form B of the entinostat compound with succinic acid can be dried by any conventional method known to those skilled in the art. In one embodiment, the drying is under vacuum.

[0050] In one embodiment, a lyophilized solid comprising entinostat and succinic acid is prepared comprising: a) dissolving a mixture of entinostat and succinic acid in a solvent mixture of acetonitrile and water to form a solution, the molar ratio of entinostat to succinic acid being about 1:0.5; and b) freeze-drying the solution to obtain a freeze-dried solid comprising entinostat and succinic acid.

[0051] In one embodiment, the lyophilized solid comprising entinostat and succinic acid is amorphous. In one embodiment, the ratio of acetonitrile to water in the solvent mixture is about 1:1. In one embodiment, about 55-65 volumes (mL), particularly about 60 volumes, of the solvent mixture per gram of entinostat weight are used. In one embodiment, dissolving further comprises sonicating the mixture of entinostat and succinic acid in the solvent mixture. In one embodiment, lyophilization comprises freezing the solution in a dry ice / acetone bath. In one embodiment, lyophilization comprises the use of a lyophilizer. In one embodiment, lyophilization occurs over several days, particularly over about 3 days.

[0052] In another embodiment, Form C of the entinostat compound having succinic acid is prepared comprising: a) combining methyl ethyl ketone with a freeze-dried solid comprising entinostat and succinic acid to form a slurry, wherein the molar ratio of entinostat to succinic acid is about 1:0.5; and b) aging the slurry to obtain Form C of the entinostat compound with succinic acid.

[0053] In one embodiment, the lyophilized solid comprising entinostat and succinic acid is amorphous. The volume of methyl ethyl ketone used is not critical as long as it is sufficient to form a slurry, but not enough to dissolve the lyophilized solid. In one embodiment, about 10 volumes of methyl ethyl ketone are used per gram of entinostat weight in the lyophilized solid. In one embodiment, the aging includes temperature cycles at room temperature and about 50° C., with each temperature for about 4 hours. In one embodiment, the aging occurs for several days, for example, about 1-4 days, particularly about 4 days. In one embodiment, the aging results in a paste, which is evaporated to dryness. Form C of the entinostat compound with succinic acid can be dried by any conventional method known to those skilled in the art. In one embodiment, the drying is under vacuum.

[0054] In one embodiment, a lyophilized solid comprising entinostat and succinic acid is prepared comprising: a) dissolving a mixture of entinostat and succinic acid in a solvent mixture of acetonitrile and water to form a solution, the molar ratio of entinostat to succinic acid being about 1:0.5; and b) freeze-drying the solution to obtain a freeze-dried solid comprising entinostat and succinic acid.

[0055] In one embodiment, the lyophilized solid comprising entinostat and succinic acid is amorphous. In one embodiment, the ratio of acetonitrile to water in the solvent mixture is about 1:1. In one embodiment, about 55-65 volumes (mL), particularly about 60 volumes, of the solvent mixture per gram of entinostat weight are used. In one embodiment, dissolving further comprises sonicating the mixture of entinostat and succinic acid in the solvent mixture. In one embodiment, lyophilization comprises freezing the solution in a dry ice / acetone bath. In one embodiment, lyophilization comprises the use of a lyophilizer. In one embodiment, lyophilization occurs over several days, particularly over about 3 days.

[0056] One embodiment of the invention is directed to Form A of the entinostat compound with maleic acid. Another embodiment of the invention is directed to Form A of the entinostat compound with succinic acid. A further embodiment is directed to Form B of the entinostat compound with succinic acid. A further embodiment is directed to Form C of the entinostat compound with succinic acid. Further embodiments of the invention are directed to any of these forms prepared by the process embodiments described herein.

[0057] The present disclosure also encompasses pharmaceutical compositions comprising one or more of Form A of the entinostat compound comprising maleic acid, Form A of the entinostat compound comprising succinic acid, Form B of the entinostat compound comprising succinic acid, and Form C of the entinostat compound comprising succinic acid, and a pharma- ceutically acceptable excipient. The pharmaceutical compositions can be prepared according to any method known in the art.

[0058] The present disclosure provides the use of one or more of Form A of the entinostat compound with maleic acid, Form A of the entinostat compound with succinic acid, Form B of the entinostat compound with succinic acid, and Form C of the entinostat compound with succinic acid in preparing a medicament for use in treating a disease.

[0059] The present disclosure provides a method of treating a disease by administering to a patient in need thereof a pharmaceutical composition comprising one or more of entinostat compound form A with maleic acid, entinostat compound form A with succinic acid, entinostat compound form B with succinic acid, and entinostat compound form C with succinic acid. The entinostat with cocrystals or salts described herein may be used in combination with hormonal therapy for the treatment of breast cancer, and in combination with immune checkpoint therapy for the treatment of NSCLC and melanoma. The entinostat with cocrystals or salts described herein may also be useful in the treatment of malignant tumors, including leukemia, colorectal cancer, ovarian cancer, oral cancer, lung cancer, breast cancer, prostate cancer, and melanoma, as well as the treatment of autoimmune diseases. The entinostat with cocrystals or salts described herein may also be used to prepare a medicament useful for treating any of the above-mentioned diseases.

[0060] The dosage of the pharmaceutical composition may vary over a wide range. The optimal dosage and dosage regimen to be administered may be easily determined by those skilled in the art and may vary with the mode of administration, the strength of the preparation, and the progression of the disease pathology. In addition, the dosage and / or regimen may need to be adjusted depending on factors related to the specific patient being treated, including the patient's sex, age, weight, diet, physical activity, administration frequency, and associated diseases. EXAMPLES

[0061] Examples 1-6 herein below provide exemplary embodiments of various entinostat cocrystals or salts.

[0062] Example 1 - Preparation of Form A of Entinostat Compound with Maleic Acid A solid mixture of entinostat (750 mg) and 0.5 equivalents of maleic acid (120 mg) is dissolved in MeCN / water (1:1) (30 vol, 22.5 ml) using sonication. The solution is divided into 4 ml vials, 1.5 ml each (approximately 50 mg free form equivalent). The solution is frozen in a dry ice / acetone bath and lyophilized over two days to obtain the co-amorphous material. The resulting co-amorphous material is wetted with 500 μl of ethanol and aged for four days with approximately 4 hour intervals at each temperature (RT / 50° C.). After four days, the resulting grey suspension is filtered and then dried under suction. The dried solid is analyzed by XRPD and determined to be Form A of the entinostat compound with maleic acid.

[0063] Form A of the entinostat compound with maleic acid is characterized by its XRPD pattern peaks. The 2θ and relative % intensity values ​​of the peaks are shown in Table 1.

[0064] [Table 4]

[0065] Angular measurements are ±0.2° 2θ. In one embodiment, important defining peaks for Form A of the entinostat compound with maleic acid include peaks at 18.6 and 18.1° 2θ. In another embodiment, important defining peaks for Form A of the entinostat compound with maleic acid further include a peak at 26.0° 2θ.

[0066] FIG. 1 provides a representative XRPD pattern of a representative sample of Form A of the entinostat compound with maleic acid.

[0067] FIG. 2 is a representative form A of the entinostat compound with maleic acid, showing the presence of about 0.4 equivalents of maleic acid and traces of residual ethanol. 1 H NMR is provided.

[0068] 3 provides a representative overlay of the TGA and DSC plots of the entinostat compound with maleic acid, Form A. The TGA shows a loss of about 5.7% by weight between about 135-170° C., and the DSC shows an endotherm with an onset at about 155° C., and an exotherm with an onset at about 161° C.

[0069] Form A of the entinostat compound with maleic acid is stable for at least 2 weeks at 40° C. / 75% RH and shows no change in form by XRPD.

[0070] Example 2 - Preparation of Form A of Entinostat Compound with Maleic Acid A solid mixture of entinostat (50 mg) and 0.5 equivalents of maleic acid (9.5 mg) is dissolved in methanol (500 μl, 10 vol) at 50° C. and cooled to 5° C. at 0.1° C. / min. At 5° C. a suspension is formed which is isolated by filtration and then dried under suction. The solid is analyzed by XRPD and determined to be Form A of the entinostat compound with maleic acid.

[0071] Example 3 - Preparation of Form A of Entinostat Compound with Succinic Acid A solid mixture of entinostat (750 mg) and 0.5 equivalents of succinic acid (122 mg) is dissolved in MeCN / water (1:1) (45 ml, 60 vol) using sonication. The solution is divided into 4 ml vials, 3 ml each (approximately 50 mg free form equivalent). The solution is frozen in a dry ice / acetone bath and lyophilized over 3 days to obtain the co-amorphous material. The resulting co-amorphous material is wetted with methanol (500 μl) and aged for 4 days at approximately 4 hour intervals at each temperature (RT / 50° C.). After 4 days, a clear solution is obtained and the methanol is allowed to evaporate while left uncapped, resulting in the precipitation of a solid. The solid is evaporated to dryness. The dried solid is analyzed by XRPD and determined to be Form A of the entinostat compound with succinic acid.

[0072] Form A of the entinostat compound with succinic acid is characterized by its XRPD pattern peaks. The 2θ and relative % intensity values ​​of the peaks are shown in Table 2.

[0073] [Table 5]

[0074] Angular measurements are ±0.2° 2θ. In one embodiment, important defining peaks for Form A of the entinostat compound with succinic acid include peaks at 18.7 and 18.3° 2θ. In another embodiment, important defining peaks for Form A of the entinostat compound with succinic acid further include a peak at 26.0° 2θ.

[0075] FIG. 4 provides a representative XRPD pattern of Form A of the entinostat compound with succinic acid.

[0076] FIG. 5 is a representative of Form A of the entinostat compound with succinic acid. 1 1 H NMR was provided, showing the presence of about 0.5 equivalents of succinic acid and a trace amount of methanol.

[0077] Figure 6 provides a representative overlay of the TGA and DSC plots of Form A of the entinostat compound with succinic acid. The TGA plot shows no weight loss until decomposition. The DSC plot shows an endotherm at about 136°C.

[0078] Figure 7 provides a representative GVS kinetic plot of Form A of the entinostat compound with succinic acid. Figure 8 provides a representative GVS isotherm plot of Form A of the entinostat compound with succinic acid. GVS shows reversible water uptake of about 0.5 wt.%. XRPD after GVS shows no change in crystal morphology during GVS.

[0079] Form A of the entinostat compound with succinic acid remains stable at 40° C. / 75% RH and 25° C. / 97% RH for at least 28 days as evidenced by XRPD.

[0080] The 4 hour solubility of Form A of the entinostat compound with succinic acid compared to known forms of entinostat is provided below.

[0081] [Table 6]

[0082] It should be noted that the XRPD pattern of the entinostat compound Form A with maleic acid is similar to the XRPD pattern of the entinostat compound Form A with succinic acid. The structures of maleic acid and succinic acid are very similar, and it is possible that the entinostat compounds may have similar structures and therefore XRPD patterns.

[0083] Without wishing to be bound, Form A of the entinostat compound with succinic acid is believed to be a hemisuccinic anhydride co-crystal of entinostat.

[0084] Example 4 - Preparation of Form A of Entinostat Compound with Succinic Acid Entinostat (500 mg) and succinic acid (0.5 eq, 84 mg) are dissolved in methanol (5 ml, 10 vol) at 50° C. The solution is then cooled to 5° C. at 0.1° C. / min. After 2 days at 5° C., the resulting suspension is filtered and dried under suction. The isolated solid is dried under vacuum at room temperature for 1.5 hours. The solid is identified by XRPD as Form A of the entinostat compound with succinic acid.

[0085] Example 5 - Preparation of Form B of Entinostat Compound with Succinic Acid A solid mixture of entinostat (750 mg) and 0.5 equivalents of succinic acid (122 mg) is dissolved in MeCN / water (1:1) (45 ml, 60 vol) using sonication. The solution is divided into 4 ml vials, 3 ml each (approximately 50 mg free form equivalent). The solution is frozen in a dry ice / acetone bath and lyophilized over a period of 3 days to obtain the co-amorphous material. The resulting co-amorphous material is wetted with methyl isobutyl ketone (500 μl) and aged for 4 days at approximately 4 hour intervals at each temperature (RT / 50° C.). After 4 days, a suspension is obtained. The suspension is filtered and dried under suction. The dried solid is analyzed by XRPD and determined to be Form B of the entinostat compound with succinic acid.

[0086] Form B of the entinostat compound with succinic acid is characterized by its XRPD pattern peaks. The 2θ and relative % intensity values ​​of the peaks are shown in Table 3.

[0087] [Table 7]

[0088] Angular measurements are ±0.2° 2θ. In one embodiment, the key defining peaks for Form B of the entinostat compound with succinic acid include at least two peaks selected from 21.5, 26.5, 23.9, and 21.7° 2θ. In another embodiment, the key defining peaks for Form B of the entinostat compound with succinic acid further include one or more peaks at 20.8, 25.4, and 17.7° 2θ.

[0089] FIG. 9 provides a representative XRPD pattern of Form B of the entinostat compound with succinic acid.

[0090] FIG. 10 is a representative sample of Form B of the entinostat compound with succinic acid, showing the presence of about 0.5 equivalents of succinic acid and trace amounts of residual methyl isobutyl ketone. 1 H NMR is provided.

[0091] 11 provides a representative overlay of the TGA and DSC plots of Form B of the entinostat compound with succinic acid. The TGA plot shows a loss of about 4.4% by weight between about 110 and 160° C. The DSC plot shows an endotherm beginning at about 134° C.

[0092] Form B of the entinostat compound with succinic acid remains stable at 40° C. / 75% RH for at least 7 days as evidenced by XRPD.

[0093] Example 6 - Preparation of Form C of Entinostat Compound with Succinic Acid A solid mixture of entinostat (750 mg) and 0.5 equivalents of succinic acid (122 mg) is dissolved in MeCN / water (1:1) (45 ml, 60 vol) using sonication. The solution is divided into 4 ml vials, 3 ml each (approximately 50 mg free form equivalent). The solution is frozen in a dry ice / acetone bath and lyophilized over a period of 3 days to obtain the co-amorphous material. The resulting co-amorphous material is moistened with methyl ethyl ketone (500 μl) and aged for 4 days at approximately 4 hour intervals at each temperature (RT / 50° C.). After 4 days, a paste is obtained. The paste is left uncapped and allowed to evaporate to dryness. The dried solid is analyzed by XRPD and determined to be Form C of the entinostat compound with succinic acid.

[0094] Form C of the entinostat compound with succinic acid is characterized by its XRPD pattern peaks. The 2θ and relative % intensity values ​​of the peaks are shown in Table 4.

[0095] [Table 8]

[0096] Angular measurements are ±0.2° 2θ. In one embodiment, the key defining peaks for Form C of the entinostat compound with succinic acid include at least two peaks selected from 4.0, 8.0, 15.7, and 19.0° 2θ. In another embodiment, the key defining peaks for Form C of the entinostat compound with succinic acid further include one or more peaks at 19.4, 26.7, and 24.1° 2θ.

[0097] FIG. 12 provides a representative XRPD pattern of Form C of the entinostat compound with succinic acid.

[0098] FIG. 13 is a representative form C of the entinostat compound. 1 H NMR is provided.

[0099] This indicates the presence of approximately 0.5 equivalents of succinic acid and no residual solvent.

[0100] 14 provides a representative overlay of the TGA and DSC plots of Form C of the entinostat compound with succinic acid. The TGA plot shows a loss of about 3.7% by weight between about 105 and 160° C. The DSC plot shows an endotherm beginning at about 134° C.

[0101] Form C of the entinostat compound with succinic acid remains stable at 40° C. / 75% RH for at least 7 days as evidenced by XRPD.

[0102] Without wishing to be bound, it is believed that Form A of the entinostat compound with succinic acid, Form B of the entinostat compound with succinic acid, and Form C of the entinostat compound with succinic acid are polymorphs of the hemisuccinic acid co-crystal of entinostat.

[0103] The above examples are set forth to aid in the understanding of the present disclosure and are not intended, and should not be construed, as limiting any of the disclosure as set forth in the claims that follow.

Claims

[Claim 1] Entinostat Form A.

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