Rabeximod Compound

Abstract

The present invention relates to a rabeximode compound selected from the HCl, methanesulfonate and malonate salts of rabeximode.

Description

[Technical field]

[0001] The present invention relates to a novel rabeximide compound.Furthermore, the present invention relates to a pharmaceutical composition comprising the rabeximide compound of the present invention.The rabeximide compound selected from the hydrochloride (HCl), methanesulfonate and malonate salts of rabeximide is particularly useful for treating a mammal, such as a human, suffering from or diagnosed with rheumatoid arthritis. [Background technology]

[0002] The compound known by the INN “rabeximode” has the IUPAC name 9-chloro-2,3-dimethyl-6-(N,N-dimethylaminoethylamino-2-oxoethyl)-6H-indolo-[2,3-b]quinoxaline and the following molecular structure: [ka]

[0003] The compound rabeximide is described in European Patent Application Publication No. EP1756111A1 and its US counterpart US2005 / 288296. In these patent publications, the preparation of rabeximide is specifically described as compound E. The process described is a small-scale process, which produces rabeximide in the form of a free base. Rabeximod as a free base is a very stable compound, nearly insoluble in water at room temperature. EP1756111 and US2005 / 288296 describe initial testing of rabeximide (compound E) in animal models of rheumatoid arthritis and multiple sclerosis. Unpublished International Application No. PCT / EP2021 / 065697 discloses the treatment of human RA patients by oral administration of rabeximide (free base). Unpublished international application PCT / EP2021 / 065693 describes the use of rabeximode (free base) for the treatment of acute respiratory syndromes, in particular those associated with pathogenic infections such as influenza virus, respiratory syncytial virus, filoviruses, arenaviruses, and coronaviruses.

[0004] To fully exploit the potential of rabeximode in these (and other) therapeutic applications in clinical practice, it is desirable to develop a rabeximode compound that combines more favorable pharmacokinetic ("PK") properties, such as high (relative) bioavailability, low peak-and-through variability, and / or low interpatient variability, with good manufacturability, formulation, and stability properties. Good manufacturability usually means that the compound is easily obtained in high purity and in a large-scale and economically viable manner. From a dosage form perspective, the compound should be easily processable into the desired dosage form(s), such as a solid oral dosage form, and also into other types of formulations, for example, keeping in mind subgroups of patients who have difficulty (or are unable) to swallow a solid oral dosage form, such as elderly patients or patients on oxygen. Of course, the drug compound, both as the (bulk) drug compound and as the finished drug product, should have sufficient chemical and / or physicochemical stability during storage and be compatible with excipients.

[0005] In practice, achieving both of these objectives is often very difficult, and there is no simple approach to develop drug compounds that combine good PK properties with optimal formulation, manufacturability, and stability characteristics.

[0006] It is an object of the present invention to provide new rabeximide compounds which have superior PK, formulation, manufacturability and / or stability properties than rabeximide free base and which, overall, are favorable candidates for practical use in clinical practice. Summary of the Invention

[0007] The present invention provides a novel rabeximide compound that meets the above objectives. More specifically, the present invention provides rabeximide in the form of a salt selected from the group consisting of hydrochloride, methanesulfonate and malonate.

[0008] As shown in the Examples, the rabeximide compounds of the invention were found to have significantly improved (oral) bioavailability in mice, as reflected by an increased AUC at comparable doses. Furthermore, the rabeximide compounds of the invention were found to produce a more favorable plasma profile, characterized by a slower decline in plasma concentrations, upon (single) oral administration.

[0009] Additionally, the raveximide compounds of the present invention are significantly more water soluble (<0.005 mg / ml) than the free base. At the same time, the raveximide compounds of the present invention are less hygroscopic and remain stable when exposed to changing humidity conditions.

[0010] Thus, in one aspect, the present invention relates to a compound selected from the group consisting of the HCl, methanesulfonic acid (mesylate) and malonate salts of a compound of formula (I). [ka]

[0011] In one embodiment, the compound is an HCl salt.

[0012] In a further embodiment, the compound is a methanesulfonate salt.

[0013] In yet another embodiment, the compound is a malonate salt.

[0014] In a further embodiment, the compounds of the invention are in solid form, preferably crystalline form, in particular the salts are in polymorphic form.

[0015] In a further embodiment, the compound is selected from salts obtainable by reaction of raveximdo, as a free base, with an acid selected from HCl, malonic acid and methanesulfonic acid.

[0016] In one embodiment, the compound is in a solid and / or undissociated form, i.e., amorphous or crystalline form. In another embodiment, the compound is in a dissolved and / or dissociated form. In a further embodiment, the compound is in a crystalline form. In yet another embodiment, the compound is in a hydrated form.

[0017] In a further embodiment, the compound is selected from salts obtainable by reaction of raveximdo, as a free base, with an acid selected from HCl, malonic acid and methanesulfonic acid.

[0018] In certain embodiments, the compound is a crystalline form of the HCl salt, more preferably a crystalline form of the HCl salt characterized by the following XRPD peaks: [Table 1]

[0019] In another particular embodiment, the compound is a crystalline form of the methanesulfonate salt, more preferably a crystalline form of the methanesulfonate salt characterized by the following XRPD peaks: [Table 2]

[0020] In a further particular embodiment, the compound is a crystalline form of the malonate salt, more preferably a crystalline form of the malonate salt characterized by the following XRPD peaks: [Table 3]

[0021] In yet another embodiment, the compound is a) mixing HCl, methanesulfonic acid or malonic acid with raveximide free base in a liquid or solvent to produce a solution or suspension of the corresponding salt; b) obtaining the salt as a solid by precipitation or crystallization, such as by cooling, evaporation of the solvent, addition of or to an antisolvent, or by addition of a co-crystallizing agent, followed by filtration or centrifugation and purification of the salt as required. Typically, the salt can be obtained by a process as described in the experimental section of this specification.

[0022] Each compound of the invention has a water solubility of greater than 0.3 mg / ml at room temperature. Some compounds have a water solubility of at least 5 mg / ml, for example 5 to 15 mg / ml, at room temperature.

[0023] In a further aspect, the invention relates to a composition comprising a compound of the invention, e.g., a compound according to any one of the above embodiments. In a further embodiment, the composition comprises the compound in solid and / or undissociated form, e.g., when the composition is a bulk powder, granule, or solid finished dosage form. In a further embodiment, the composition comprises a salt in dissolved and / or dissociated form, e.g., when the composition is a liquid finished dosage form, or an aqueous solution formed and / or used in the manufacture of a solid dosage form, etc.

[0024] In a further aspect, the invention relates to a pharmaceutical composition comprising a compound of the invention, such as a compound according to any one of the above embodiments, and optionally a pharma- ceutically acceptable excipient.

[0025] In yet another aspect, the present invention relates to a compound of the present invention, such as a compound according to any one of the above embodiments, for use in a method of treating a mammal, preferably a human subject, in need of treatment, such as a human subject suffering from or diagnosed with rheumatoid arthritis, preferably moderate rheumatoid arthritis, severe rheumatoid arthritis, or moderate to severe rheumatoid arthritis, or a human subject suffering from an acute respiratory syndrome that may be associated with a pathogenic infection. In yet another aspect, the present invention relates to a compound of the present invention, such as a compound according to any one of the above embodiments, for use in a method of treating rheumatoid arthritis, preferably moderate rheumatoid arthritis, severe rheumatoid arthritis, or moderate to severe rheumatoid arthritis, or for treating an acute respiratory syndrome that may be associated with a pathogenic infection in a mammal, such as a human subject in need of treatment.

[0026] In a further aspect, the invention relates to a method of treating a mammal, preferably a human subject, in need of treatment, such as a human subject suffering from or diagnosed with rheumatoid arthritis, preferably moderate rheumatoid arthritis, severe rheumatoid arthritis, or moderate to severe rheumatoid arthritis, comprising administering to the mammal a compound of the invention, such as a salt as described in any one of the above embodiments. In yet another aspect, the invention relates to a method of treating rheumatoid arthritis, preferably moderate rheumatoid arthritis, severe rheumatoid arthritis, or moderate to severe rheumatoid arthritis, or a method of treating an acute respiratory syndrome possibly associated with a pathogenic infection in a human subject, comprising administering to the mammal a compound of the invention, such as a salt as described in any one of the above embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Throughout this application, the terms "rabeximode", "rabeximide" and "9-chloro-2,3-dimethyl-6-(N,N-dimethylaminoethylamino-2-oxoethyl)-6H-indolo-[2,3-b]quinoxaline" may be used interchangeably and refer to any solid or liquid form of the compound, unless otherwise indicated or implied under specific circumstances.

[0028] Rabeximod can be obtained and subsequently purified and isolated from the processes described in EP1756111A1 and US2005 / 288296. Additionally, rabeximide free base in crystalline form can be obtained as described in European Patent Application No. 20179279.3 (unpublished).

[0029] Several HCl, Mao, and Mes salts of rabeximide have been crystallized to obtain new salt forms with improved physicochemical properties compared to rabeximide free base. These rabeximide compounds possess a highly advantageous combination of properties with respect to solubility, crystallinity, physical stability, thermal behavior, processability, and hydration properties, as illustrated by the experiments described in the experimental section.

[0030] As used herein, the term "counterion" refers to an acidic counterion that forms a salt with the protonated laveximide free base. When laveximide salts are described herein, they may be designated using a three-letter code that identifies the counterion. The following table lists and defines certain three-letter codes used in the literature herein. The use of three-letter codes identifies laveximide salts, e.g., the hydrochloride salt of laveximide is designated by the code HCl. The description of laveximide salts, such as HCl, includes any form of the salt, such as solid, amorphous, dissolved, or polymorphic.

[0031] As mentioned above, the compositions disclosed herein, particularly the pharmaceutical compositions, may further comprise at least one pharma- ceutically acceptable adjuvant, diluent, excipient and / or carrier in addition to the compounds disclosed herein. Such pharma-ceutically acceptable adjuvant, diluent, excipient and / or carrier may be selected from the group consisting of, but not limited to, oleic acid, Tween 80, sodium carboxymethylcellulose.

[0032] In some embodiments, the pharmaceutical composition comprises 1-99% by weight of said at least one pharma- ceutically acceptable adjuvant, diluent, excipient and / or carrier, and 1-99% by weight of the compound of formula I disclosed herein. The total amount of active ingredient and pharma- ceutically acceptable adjuvant, diluent, excipient and / or carrier should not exceed 100% (100% w / w) by weight of the composition, in particular the pharmaceutical composition.

[0033] According to various aspects of the present invention, the composition is preferably provided in the form of a unit dosage form. The term "unit dosage form" refers to a physically discrete unit suitable as a unit dosage for a human subject, each unit containing a predetermined amount of active agent calculated to produce a desired therapeutic effect, in association with any suitable pharmaceutical carrier(s) and / or excipient(s). Exemplary, non-limiting unit dosage forms include tablets (e.g., chewable tablets), caplets, capsules (e.g., hard or soft capsules), and the like. According to a preferred embodiment of the present invention, the unit dosage form is a unit dosage form suitable for oral administration. Most preferably, it is a solid unit dosage form such as a tablet or capsule, most preferably a capsule, such as a standard gelatin capsule filled with powder as defined elsewhere herein.

[0034] In another embodiment of the present invention, the rabeximide compound may be provided in the form of a liquid oral dosage form, which is a preferred or necessary oral dosage form for patients who have difficulty swallowing. Liquid oral dosage forms require a stable, dissolved, or suspended form of the drug that meets the release, bioavailability, stability, and taste requirements.

[0035] In another embodiment of the present invention, the rabeximide compound may be provided in the form of a sterile solution suitable for parenteral administration, such as administration by intravenous injection or infusion. Such parenteral formulations may be the preferred or necessary mode of administration for patients suffering from severe respiratory disease, such as those intubated and artificially kept in a coma. Sterile parenteral dosage forms require the drug to be in a stable, dissolved, or suspended form that meets the release, bioavailability, and stability requirements.

[0036] A person of average skill in the art can devise and develop suitable formulations based on the present teachings and relying on common general knowledge as reflected in textbooks such as Remington's Pharmaceutical Sciences (Meade Publishing Co., Easton, Pa., 20th Ed., 2000), the entire disclosures of which are incorporated herein by reference.

[0037] In a broader sense, the present invention also relates to a method of treating a subject in need thereof, said treatment comprising administering to said subject a composition, formulation or unit dosage form comprising a rabeximide compound of the present invention, preferably said rabeximide compound as defined herein. In a preferred embodiment of the present invention, the subject to be treated is a human subject, preferably a human.

[0038] In a first embodiment, the present invention also relates to a method of treating a subject suffering from and / or diagnosed with rheumatoid arthritis or a related condition, the method comprising administration of a rabeximide compound of the present invention.

[0039] In a further embodiment, the present invention also relates to a method of treating a subject suffering from acute respiratory syndrome, optionally related to a pathogenic infection, such as a coronavirus infection, comprising administration of a rabeximide compound of the present invention.

[0040] The terms "treatment" and "treating" as used herein refer to the management and care of a patient for the purpose of combating a condition, such as a disease or disorder. The terms are intended to include the full range of treatments for a given condition suffered by a patient, such as administration of active compounds to slow the progression of a disease, disorder or condition, to alleviate or relieve symptoms or complications, and / or to cure or eliminate a disease, disorder or condition, as well as to prevent a condition, and prevention is understood to refer to the management and care of a patient for the purpose of combating a disease, condition or disorder, including administration of active compounds to prevent the onset of symptoms or complications. Treatment can be performed in either an acute or chronic manner. The patient to be treated is preferably a mammal, particularly a human, but may also include animals such as dogs, cats, cows, sheep, pigs, etc.

[0041] Specific embodiments of processes for making the compounds of the invention are described in the experimental section of this specification, and each individual process and each starting material constitutes an embodiment that may form part of an embodiment.

[0042] As used herein, the term "and / or" is intended to refer to each alternative individually as well as both alternatives. For example, the phrase "xxx and / or yyy" means "xxx and yyy," "xxx," or "yyy," with all three alternatives being subject to separate embodiments.

[0043] As used herein, "pharmaceutical acceptable excipients" include, but are not limited to, carriers, excipients, diluents, adjuvants, colorants, flavorings, preservatives, and the like that a person skilled in the art would consider using when formulating raveximide to produce a pharmaceutical composition.

[0044] Adjuvants, diluents, excipients and / or carriers that may be used in the compositions of the present invention should be pharma- ceutically acceptable, in the sense of being compatible with rabexim- od and other components of the pharmaceutical composition and not harmful to the recipient. Desirably, the compositions do not contain any substances that may cause adverse reactions, such as allergic reactions. Adjuvants, diluents, excipients and carriers that may be used in the pharmaceutical compositions of the present invention are well known to those skilled in the art.

[0045] Unless otherwise indicated, all exact values ​​provided herein represent corresponding approximations (e.g., all exact exemplary values ​​provided with respect to a particular factor or measurement can also be considered to provide corresponding approximate measurements, modified by "about" where appropriate).

[0046] All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context.

[0047] Any and all examples provided herein, or the use of exemplary language (e.g., "etc.") are intended merely to better clarify the invention and do not pose limitations on the scope of the invention unless otherwise indicated. No language in the specification should be construed as indicating any element as essential to the practice of the invention unless expressly so stated.

[0048] The citation and incorporation of patent documents herein is done for convenience only and does not reflect any opinion as to the validity, patentability and / or enforceability of such patent documents.

[0049] Any aspect or embodiment of the invention using terms such as "comprising," "having," "including," or "containing" in reference to an element or elements is intended to support similar aspects or embodiments of the invention that "consist," "consist essentially of," or "substantially comprise" that particular element, unless otherwise indicated or clearly contradicted by context (e.g., a composition described herein as comprising a particular element should be understood to also describe a composition consisting of that element, unless otherwise indicated or clearly contradicted by context).

[0050] This invention includes all modifications and equivalents of the subject matter recited in the embodiments and claims presented herein to the fullest extent permitted by applicable law.

[0051] The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of protection. The features disclosed in the foregoing description and in the following examples may, both individually and in any combination thereof, be material for realizing the invention in diverse forms thereof.

[0052] The above embodiments should be considered to refer to any of the aspects described herein (such as "methods of treatment," "pharmaceutical compositions," "compounds for use as medicaments," or "compounds for use in methods"), as well as any of the embodiments described herein, unless the embodiment is specified to be related to a particular aspect or aspects of the invention.

[0053] All references cited in this specification, including published applications, patent applications, and patents, are hereby incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference in its entirety.

[0054] All headings and sub-headings used herein are used for convenience only and should not be construed as limiting the invention.

[0055] Any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

[0056] The recitation of ranges of values ​​herein, unless otherwise indicated herein, is intended to serve merely as a shorthand method of referring individually to each separate value falling within the range, and each separate value is incorporated herein as if it were individually recited herein. Unless otherwise indicated, all precise values ​​provided herein represent corresponding approximations (e.g., all precise exemplary values ​​provided with respect to a particular factor or measurement can also be considered to provide a corresponding approximate measurement, modified by "about" where appropriate).

[0057] All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context.

[0058] Any and all examples provided herein, or the use of exemplary language (e.g., "etc.") are intended merely to better clarify the invention and do not pose limitations on the scope of the invention unless otherwise indicated. No language in the specification should be construed as indicating any element as essential to the practice of the invention unless expressly so stated. [Brief description of the drawings]

[0059] [Figure 1] FIG. 1 shows the XRPD diffractogram of the prepared crystalline HCl salt form. [Diagram 2] 1 shows XRPD diffractograms of prepared crystalline Mao salt forms. [Diagram 3]1 shows the XRPD diffractogram of the prepared crystalline Mes salt form. [Figure 4] Figure 1 shows the temperature profile applied in the crystallization experiments of the methanesulfonate salt. The temperature was varied from 5 to 50°C at a rate of 0.17°C / min. The initial and final temperatures were 25°C. [Diagram 5] Figure 1 shows the temperature profile applied in the crystallization experiments of the hydrochloride and malonate salts. The temperature was varied from 5 to 50°C at a rate of 0.17°C / min. The initial and final temperatures were 25°C. [Figure 6] TGMS analysis of Mes salt (experiment ID: TCS35) between 25 and 300 °C (heating rate 10 °C / min) is shown. From 25 to 220 °C, a mass loss of 4.9% was measured. [Figure 7] Figure 1 shows the DSC trace of Mes salt (Experiment ID: TCS35) between 25 and 300 °C (heating rate 10 °C / min). The endothermic event between room temperature and 110 °C can be attributed to the loss of moisture. The melting of the API can be associated with a sudden endothermic reaction at 257 °C. [Figure 8] LCMS chromatogram of Mes salt (Experiment ID: TCS35) is shown. The retention time of API was 1.66 min. MS spectrum confirmed the molecular weight of the compound to be 409.9 g / mol and the [M+H]+ ion was m / z 410.3. [Figure 9] The H-NMR spectra of the Mes salt (Experiment ID: TCS35, top) and the free base (SM, top) measured in DMSO-d6 are shown. In addition to rabeximide, signals for water (3.4 ppm), DMSO (2.5 ppm), and methanesulfonic acid (CH3 at 2.53 ppm, OH at 9.3 ppm) were detected. [Figure 10] 13C-NMR-APT spectrum of Mes salt (Experiment ID: TCS35) measured in DMSO-d6. CH and CH3 groups are positive signals, while CH2 and quaternary carbons are negative signals. In addition to API, methanesulfonic acid and DMSO signals are present. [Figure 11A]Plots of moisture adsorption kinetics (A) and isotherm (B) for Mes salt (experiment ID: TCS35) are shown, with the first adsorption cycle from 40% RH to 95% RH, followed by desorption from 95% RH to 0% RH, and then from 0% RH to 40% RH in 10% RH increments, with a minimum step time of 10 min and a maximum step time of 6 h. [Figure 11B] Plots of moisture adsorption kinetics (A) and isotherm (B) for Mes salt (experiment ID: TCS35) are shown, with the first adsorption cycle from 40% RH to 95% RH, followed by desorption from 95% RH to 0% RH, and then from 0% RH to 40% RH in 10% RH increments, with a minimum step time of 10 min and a maximum step time of 6 h. [Figure 12] TGMS analysis of the HCl salt (Experiment ID: TCS160) between 25 and 300 °C (heating rate 10 °C / min). A mass loss of about 0.3% was recorded between about 25 and 80 °C. An endothermic event at 285 °C probably indicates melting. [Figure 13] Shown is the DSC trace of the HCl salt (Experiment ID: TCS160) between 25 and 300°C (heating rate 10°C / min). The melting of the API can be associated with a sharp endothermic reaction at 294°C. [Figure 14] 1H-NMR spectrum of the HCl salt (Experiment ID: TCS160). In addition to the API, signals of DMSO-d6, 2-propanol and TMS were detected. [Figure 15A] Plots of moisture adsorption kinetics (A) and isotherm (B) for HCl salt (Experiment ID: TCS160) are shown, where the first adsorption cycle was from 40% RH to 95% RH, followed by desorption from 95% RH to 0% RH, and then from 0% RH to 40% RH in 10% RH increments, with a minimum step time of 10 min and a maximum step time of 6 h. [Figure 15B] Plots of moisture adsorption kinetics (A) and isotherm (B) for HCl salt (Experiment ID: TCS160) are shown, where the first adsorption cycle was from 40% RH to 95% RH, followed by desorption from 95% RH to 0% RH, and then from 0% RH to 40% RH in 10% RH increments, with a minimum step time of 10 min and a maximum step time of 6 h. [Figure 16]1 shows the mean (±SD) plasma concentration versus time profiles of raveximide and raveximide salt following intravenous administration at a nominal dose of 3.00 mg / kg to male CD1 mice (n=3 / time point). [Figure 17] 1 shows the mean (±SD) plasma concentration versus time profiles of rabeximide and rabeximide salts following oral administration at a nominal dose of 30.00 mg / kg to male CD1 mice (n=3 / time point). EXAMPLES

[0060] General Experimental Information Common Abbreviations 1 H-NMR Proton Nuclear Magnetic Resonance 13 C-NMR carbon-13 nuclear magnetic resonance AAC accelerated aging conditions (40℃ and 75%RH) Am amorphous APT Attached Proton Test API Active Pharmaceutical Ingredient DSC Differential Scanning Calorimetry GEN Amorphous Feasibility Test Experiment ID HR-XRPD High Resolution X-ray Powder Diffraction HT-XRPD High Throughput X-ray Powder Diffraction LCMS High Performance Liquid Chromatography / Mass Spectrometry MS mass spectrometry Pc crystallinity is poor PAMPA Parallel Artificial Membrane Permeability Assay PLM Polarizing Microscope RF Response Factor RH Relative Humidity RT room temperature Ssm Experiment ID for salt crystallization experiment under isothermal conditions TCS Experiment ID for salt crystallization experiment involving thermal cycling TGMS Thermogravimetric analysis / mass spectrometry

[0061] chemicals Ace Acetone AcN Acetonitrile EtOH Ethanol IPA Isopropanol, 2-propanol MeOH Methanol MEK Methyl ethyl ketone THF Tetrahydrofuran

[0062] Analysis method X-ray powder diffraction XRPD patterns were obtained using a high-throughput XRPD instrument. The plates were mounted on a Bruker General Area Detector Diffraction System (GADDS) equipped with a VÅNTEC-500 gas area detector corrected for intensity and shape variations. Calibration of measurement accuracy (peak positions) was performed using NIST SRM1976 standards (Corundum).

[0063] Data collection was performed at room temperature using monochromatic Cu Kα radiation in the 2θ region of 1.5°-41.5°, which is the most characteristic part of the XRPD pattern. Diffraction patterns for each well were collected in two 2θ ranges (1.5°≦2θ≦21.5° for the first frame, and 19.5°≦2θ≦41.5° for the second frame) with an exposure time of 90 seconds for each frame. No background subtraction or curve smoothing was applied to the XRPD patterns.

[0064] High-resolution X-ray powder diffraction measurements HR-XRPD data were collected at room temperature using a germanium monochromator at Cu K α1 The diffraction data were collected on a D8 Advance diffractometer using a 1.5 nm NMR radiation (1.54056 Å). Diffraction data were collected in the range 2-41.5° 2θ. Detector scans on a solid-state LynxEye detector were performed using 0.015° per step at a scan rate of 10 s / step. Samples were measured in 8 mm long glass capillaries with an outer diameter of 0.5 mm.

[0065] TGA / SDTA and TGMS analysis Mass loss due to solvent or water loss from the crystals was determined by TGA / DSC. The weight of the sample was monitored during heating on a TGA / DSC3+STARe system (Mettler-Toledo GmbH, Switzerland), providing weight vs. temperature curves and heat flow signals. The TGA / DSC3+ was temperature calibrated using indium and aluminum samples. Samples (approximately 1 mg) were weighed into 100 μL aluminum crucibles and sealed. A pinhole was pierced in the lid and the crucibles were heated in the TGA from 25 to 300 °C at a heating rate of 10 °C / min. Dry N2 gas was used for purging.

[0066] The gases evolved from the TGA samples were analyzed by a mass spectrometer Omnistar GSD301T2 (Pfeiffer Vacuum GmbH, Germany), which is a quadrupole mass spectrometer that analyzes mass in the temperature range of 0 to 200 amu.

[0067] DSC analysis Thermal events were taken from DSC thermograms recorded on a heat flux DSC3+STARe system (Mettler-Toledo GmbH, Switzerland). The DSC3+ was calibrated for temperature and enthalpy using small pieces of indium (mp=156.6°C, δHf=28.45 J / g) and zinc (mp=419.6°C; δHf=107.5 J / g). Samples (approximately 1 mg) were sealed in standard 40 μL aluminum pans, pin-punctured, and heated in the DSC from 25°C to 300°C at a heating rate of 10°C / min unless otherwise specified. Dry N2 gas was used to purge the DSC instrument during the measurements at a flow rate of 50 mL / min.

[0068] cDSC analysis Cycling DSC was measured in standard 40 μL aluminum pans, pinhole drilled and heated in the DSC to various temperatures starting from 25° C. and then cooled to 25° C. The heating and cooling rates were 10° C. / min. Dry N2 gas was used to purge the DSC instrument during the measurements at a flow rate of 50 mL / min. After the experiment, the solids were removed from the pans and analyzed by HT-XRPD.

[0069] Polarizing microscope Polarized light micrographs were collected on a Leica DM2500M optical microscope. Samples were mounted on glass slides and measured as dry solids.

[0070] LCMS analysis method LC parameters [Table 4]

[0071] Compound integrity is expressed as a percentage of the peak area calculated from the area of ​​each peak in the chromatogram excluding the "injection peak" and the total peak area as follows:

number

[0072] The peak area percentage of the compound of interest is utilized as an indication of the purity of the constituents in the sample.

[0073] For the HPLC assay, a solution of raveximide (SM) was measured as a reference and the peak area was assigned to 100% recovery after taking into account the amount of solvent determined by TGMS. Salt samples were measured in the same way and the recovery was calculated again taking into account the amount of solvent. For all salts measured, recoveries <100% could be assigned to the API and the remaining % recovery could be assigned to the counterion, from which the API:counterion ratio could be determined.

[0074] 1 H-NMR In DMSO-d6 1 H-NMR spectroscopy was used to characterize the integrity of the compounds and to determine the salt stoichiometry. Spectra were recorded at room temperature (32 scans) on a 500 MHz instrument (Bruker BioSpin GmbH) using standard pulse sequences. Data were processed using ACD Labs software Spectrus Processor 2016.2.2 (Advanced Chemistry Development Inc. Canada).

[0075] 13 C-NMR Compound integrity characterization was performed using DMSO-d6 13 C-NMR-APT spectroscopy was used. Spectra were recorded at room temperature (2048 scans) on a 500 MHz instrument (Bruker BioSpin GmbH) using standard pulse sequences. Data were processed using ACD Labs software Spectrus Processor 2016.2.2 (Advanced Chemistry Development Inc. Canada).

[0076] Dynamic Vapor Sorption Differences in hygroscopicity (water absorption) of solid materials in various forms provide a measure of their relative stability against increasing relative humidity. Moisture sorption isotherms of small samples were obtained using a DVS-1 system from Surface Measurement Systems (London, UK). This instrument is suitable for use with a few milligrams of sample, with an accuracy of 0.1 μg. Relative humidity was varied during adsorption-desorption-adsorption (40-95-0-40% RH) at a constant temperature of 25 °C. Weight balance for each step was set at dm / dt < 0.0002 mg / min for a minimum of 1 h or a maximum of 6 h. Samples were then measured by HT-XRPD.

[0077] Hygroscopicity was classified according to the European Pharmacopoeia Hygroscopicity Classification. The water absorption rate at 25°C / 80% RH (24 hours) is as follows: Mass change <0.2% - non-hygroscopic Mass change >0.2% & <2% - slightly hygroscopic Mass change >2% & <15% - moderate hygroscopicity Mass change rate >15% - Very hygroscopic

[0078] The particular crystalline form of raveximide free base is designated "Form 1." Form 1 was an anhydrous material that melted at 260°C. The chemical purity of the starting material was high as determined by 1H-NMR and LCMS. Form 1 was slightly hygroscopic and remained physically stable when exposed to relative humidity values ​​of 0-95%.

[0079] Example 1: Preparation of compounds of the present invention Materials and Methods All chemicals were obtained from Fisher Scientific or Sigma Aldrich. Chemicals used were of at least research grade. Solvents used for UPLC analysis were of HPLC grade.

[0080] Salt formation and crystallization A set of 1.8 ml vials was prepared, each containing 20 mg of raveximide free base. To each vial was added a magnetic stir bar and 1.1 equivalents of the selected acid. The acid was added as a 1 M or 2 M aqueous solution. In addition, a set of 1.8 ml vials was prepared containing only the API. 750 μl of the selected solvent was then added. The vials were transferred to a Crystal16™ parallel crystallizer and the suspension was stirred at 750 rpm. The experiments with methanesulfonic acid were performed following the temperature profile shown in Figure 4. Slightly different temperature profiles were applied for hydrochloric and malonic acids (Figure 5).

[0081] All mixtures were heated from 25° C. to 50° C., after which the mixtures were stirred at 50° C. for 1 hour. The temperature was then reduced to 5° C., and the mixtures were stirred at 5° C. for 1 hour. Another heating-cooling cycle was applied, and the mixtures were again stirred at 50° C. for 1 hour. The applied heating and cooling rates were -0.17° C. / min. Depending on the type of acid used, the final steps of the temperature program were as follows: In the experiments involving hydrochloric acid, the temperature was set from 50° C. to 25° C. immediately. After reaching 25° C., the mixture was incubated at 25° C. for 3 days without stirring.

[0082] After completion of the temperature program, the suspension was centrifuged to separate the solids, dried under vacuum (50° C., 5 mbar, 18 h) and analyzed by HT-XRPD. In experiments where no suspension was obtained, the solvent was evaporated completely. The mother liquor from most experiments where a solid formed was also evaporated to dryness. The solids obtained by solvent evaporation were analyzed by HT-XRPD.

[0083] All solids were exposed to AAC (40° C. / 75% RH, 3 days) and re-measured by HT-XRPD. Afterwards, 750 μl of selected solvent was added. The vials were transferred to a Crystal16™ parallel crystallizer and the suspension was stirred at 750 rpm and 50° C. for 18 hours, after which the suspension was centrifuged and the solids were separated, dried under vacuum (50° C., 5 mbar, 18 hours) and analyzed by HT-XRPD. The experimental conditions and results are shown in Tables 1 and 2 below for the first and second set of experiments, respectively. The obtained XRPD patterns of the prepared crystalline salts are shown in Figure 1 (HCl), Figure 2 (Mao) and Figure 3 (Mes). [Table 5]

[0084] Methanesulfonic acid experimental conditions and results. In all experiments, 750 μl of solvent was used. The counterion (CI) abbreviations refer to the pure counterion, whereas counterions with numbers refer to the new salt form. After subjecting API:CI suspensions to thermal cycling (TCS experiments) or isothermal conditions (Ssm experiments), the solids were isolated, dried (5 mbar, 50 °C, 18 h) and analyzed by XRPD. In some experiments, the liquid phase was dried and the resulting solids were analyzed by XRPD. Most solids were subjected to AAC (40 °C, 75% RH, 3 days) and re-measured by XRPD. [Table 6]

[0085] Experimental conditions and results of crystallization experiments of the hydrochloride and malonate salts. 750 μl of solvent was used in all experiments. The abbreviation of counterion (CI) refers to the pure counterion, whereas the counterion with a number refers to the new salt form. After subjecting the API:CI suspension to thermal cycling, the solid was isolated, dried (5 mbar, 50° C., 18 h) and analyzed by XRPD. The liquid phase was dried and the resulting solid was analyzed by XRPD. Most of the solid was subjected to AAC (40° C., 75% RH, 3 days) and re-measured by XRPD. [Table 7] *=pyrolysis<150℃ AAC refers to accelerated aging conditions (40°C, 75% RH for 3 days).

[0086] Table 3 provides an overview of the salt forms obtained in this study. The solubility of the salts in water at room temperature was estimated by adding water until the salt dissolved. All salts showed higher solubility than the free base (<0.005mg / ml) as indicated by the way the salts interacted with water. All salts had good solution in water, while the free base showed no signs of dissolution. From the TGMS data it was estimated whether the salts were stoichiometric hydrates.

[0087] Example 2: Scale-up experiments Preparations of selected salts were carried out on a larger scale to obtain additional material for further analytical characterization. Experiments started with either 100 mg (first set) or 1200 mg (second set) of raveximode free base (Form 1, starting material). For the 100 mg experiments, the starting material was weighed into an 8 ml vial containing a magnetic stir bar. The 1200 mg experiments were carried out in a 100 ml Mettler Toledo MultiMax™ crystallizer equipped with an overhead stirrer. The selected acid was added as a 1 M or 2 M aqueous solution. The selected solvent was then added and stirred at a stirring speed of 750 rpm. The stirred suspension was subjected to a temperature profile similar to that described in Figure 5, but with a final 9 hour incubation period at 25°C.

[0088] After temperature cycling, the suspension was filtered using vacuum filtration combined with a Buchner funnel. The solids were dried at ambient conditions for 18 hours and samples were measured by XRPD. The solids from runs TCS32-34 and TCS36 were further dried at 50° C. and 5 mbar for 18 hours. The solids from run TCS35 were further dried at room temperature and 200 mbar for 4 days, and the solids from run TCS37 were further dried at 50° C. and 5 mbar for 4 days.

[0089] The experimental conditions and XRPD results of scale-up experiments of selected raveximide salts are shown in Table 4. The abbreviation of counterion (CI) indicates the pure counterion, while the counterion with a number indicates the new salt form of the API. "AAC" means that the sample was exposed to 40°C / 75% RH for 3 days before analysis by XRPD. The materials were dried under vacuum conditions, the details of which are described below. [Table 8] a At room temperature and 200 mbar for 4 days, b 1 day at room temperature and 5 mbar.

[0090] TGMS, DSC, LCMS of MES salt and HCl salt 1 H-NMR,13 The results of C-NMR-APT and moisture sorption analysis are shown in Figures 6-11 and 7-15, respectively. These results confirm that each product is of high purity and has good stability properties.

[0091] Example 3: Solubility Qualitative solubility measurement The solubility of selected salts from the salt screen was estimated in water at room temperature: 50 μl aliquots of solvent were added to approximately 2 mg of salt until the material was dissolved as observed by the naked eye.

[0092] Qualitative solubility measurement The thermodynamic solubility of raveximide free base (Form 1) was measured in three different USP buffers (50 mM) ranging from pH 1.2 to pH 7.4 and in water (Experiment ID: QSA21-24) by the shake flask method at 25 °C (Table 5). Approximately 30 mg was added to approximately 1 ml of the selected buffer and the resulting suspension was equilibrated for 4 hours at room temperature with continuous stirring. After stirring for 15 minutes and 4 hours, the pH of the solution was recorded. Upon completion of the equilibration time, the suspension was centrifuged. The solution was filtered and diluted, followed by LCMS analysis to determine the API concentration in the solution. The residue was dried under vacuum and the resulting dry solid was analyzed by XRPD. A standard LC calibration curve was constructed and the diluted mother liquor was measured to determine the API concentration.

[0093] The solubility of the free base (form 1) and salts prepared by scale-up was measured in water at room temperature. The suspension was stirred for 18 hours, after which the liquid phase was separated and measured against a calibration curve by LCMS. The solid was dried and measured by XRPD to determine the form of the solid. The results are summarized in the table below. The lowest solubility was determined for the free base (form 1). Since the signal was lower than the calibration curve, the solubility was determined to be <0.005 mg / ml. The solubility in water of the two anhydrous salts Mao1 and HCl1 was 5.3 mg / ml and 5.5 mg / ml, respectively. The highest solubility was tested for Mes1, which showed a solubility of 13.3 mg / ml. The experimental details are given in Table 5. Table 5. Experimental details and results for solubility measurements of raveximide free base form 1) and salt Mes1 in water and three buffers ranging from pH 1.2 to 7.4. The pH of the solutions after 15 min and 4 h is reported. Solubility was determined by measuring the liquid phase against a calibration line by LCMS after 4 h of equilibration. [Table 9]

[0094] Example 4: Pharmacokinetic properties Preparation of formulations IV formulations were prepared on the day of dosing. Formulations were prepared by weighing compound into brown glass vials. On the day of dosing, ClinOleic 20% intravenous lipid emulsion (200 μg / mL, Tamro) was added to the tube (1.5 mg / mL in 20% ClinOleic). Formulations were homogenized 5 minutes prior to dosing. IV formulations were administered within 5 hours of preparation.

[0095] PO formulations were prepared the day before dosing. Formulations were prepared by combining the test items in the PO vehicle (6 mg / ml in 0.45% (v / v) Tween 80 in tap water, 0.11% (w / v) sodium carboxymethylcellulose (CMC)). The suspension was mixed by vortexing and kept refrigerated (+4°C) overnight. On the day of dosing, the formulations were homogenized 15 min prior to dosing.

[0096] Animal testing Naïve animals were used in this study (see Table 6). Groups of six mice were housed in individually ventilated (IVC) cages. The cages were equipped with aspen bedding (4HP and PM90L, Tapvei, Estonia) and paper bundles (Sizzlenest, Datesand, UK) as nesting materials, and with paper pulp cabins and red polycarbonate cylinders (Datesand, UK) as cage enrichment. Temperature (22 ± 2°C), humidity (55 ± 10%), air exchange rate (75 times / h), and a 12 / 12-h light / dark cycle (lights on at 6 am, 500 lux, lights on at 6 pm, 1.5 lux) of the animal room were automatically controlled and maintained. Animals were allowed to acclimate to the site for at least 5 days prior to the study. Animals had free access to food (SDS diet, RM1(E)801002, Special Diets Services, UK) and tap water at all times and their wellness was ensured by daily observation. [Table 10] *All animals were weighed the day before dosing.

[0097] The study compounds were administered by the designated route, and the time of administration and blood collection were recorded. Within 30 min after sampling, blood was centrifuged to separate plasma (room temperature, 10 min, 2700G). Plasma samples were transferred to plastic tubes and stored frozen at -20°C until analysis. Clinical signs and general behavior of the animals were recorded, as appropriate.

[0098] Pharmacokinetic analysis Pharmacokinetic parameters were calculated by non-compartmental analysis (NCA) using Phoenix64 (Build 6.4.0.768) WinNonlin (Version 6.4) software. Nominal doses were used for all animals. Terminal half-life (T 1 / 2 ) was calculated by least-squares regression analysis of the terminal linear portion of the log concentration-time curve. The area under the plasma concentration-time curve (AUC) was calculated as the area under the plasma concentration-time curve (AUC) relative to the last measurable concentration (AUC 0-last) were determined using the linear trapezoidal rule for increasing values ​​and the logarithmic trapezoidal rule for decreasing values, with extrapolation to infinity of the terminal elimination phase used where possible. The following criteria were used: -Minimum 3 points (C max (excluding) is used (R 2 Adjustment value > 0.85) T 1 / 2 is less time than is used to compute lambda AUC inf_Extrap %<20%

[0099] Maximum plasma concentration (C max ) and C max Time to reach (t max ) were derived directly from the plasma concentration data.

[0100] The mean (±SD) plasma concentration versus time profiles following intravenous and oral administration of raveximode and raveximode salt are shown in Figures 16 and 17. These figures show the following results:

[0101] After intravenous administration of raveximode at 3.00 mg / kg as the free base, plasma concentrations peaked at the first sampling time of 0.0833 hours post-dose, with a mean C max was 150ng / ml, and the mean C0 was 351ng / ml. AUC 0-inf and T 1 / 2 The values ​​of CL and V were 681h*ng / ml and 8.99h, respectively. ss The values ​​of C and D were 73.4 ml*min / kg (61.2% of mouse liver blood flow (120 ml / min / kg; Ring et al., 2011)) and 49.4 l / kg, respectively. After oral administration of 30.0 mg / kg raveximode, the plasma concentration peaked at 4.00 hours after administration, and the mean C max The AUC 0-last The value was 8330h*ng / ml.

[0102] After intravenous administration of rabeximide HCl at 3.00 mg / kg, plasma concentrations peaked at the first sampling time of 0.0833 hours post-dose, with a mean C max was 454ng / ml, and the mean C0 was 600ng / ml. AUC 0-inf and T 1 / 2 The values ​​of CL and V were 2220h*ng / ml and 8.43h, respectively. ss The AUC values ​​were 22.6 ml*min / kg (18.8% of mouse liver blood flow (120 ml / min / kg)) and 14.2 l / kg, respectively. After oral administration of 30.0 mg / kg raveximide HCl, the plasma concentration peaked at 4.00 hours after administration, with a mean Cmax of 893 ng / ml. 0-last The value was 13,700h*ng / ml.

[0103] After intravenous administration of rabeximide at 3.00 mg / kg, plasma concentrations peaked at the first sampling time of 0.0833 hours post-dose, with a mean C max The mean C0 was 390ng / ml. AUC 0-inf and T 1 / 2 The values ​​of CL and V were 1870h*ng / ml and 8.43h, respectively. ss The values ​​of raveximide (Mao) were 26.8 ml*min / kg (22.3% of the mouse liver blood flow (120 ml / min / kg)) and 16.9 l / kg, respectively. After oral administration of 30.0 mg / kg, the plasma concentration peaked 0.17 hours after administration, and the mean C max The AUC 0-last The value was 11,400h*ng / ml.

[0104] After intravenous administration of rabeximide Mes at 3.00 mg / kg, plasma concentrations peaked at the first sampling time of 0.0833 hours post-dose, with a mean C max The mean C0 was 507ng / ml. AUC 0-inf and T 1 / 2 The values ​​of CL and V were 2320h*ng / ml and 9.80h, respectively.ss The values ​​of rabeximide Mes were 21.5 ml*min / kg (17.9% of the mouse liver blood flow (120 ml / min / kg)) and 15.9 l / kg, respectively. After oral administration of 30.0 mg / kg, the plasma concentration peaked at 2.00 hours after administration, and the mean C max The AUC 0-last and T 1 / 2 The values ​​were 11 600h*ng / ml and 8.93h, respectively.

[0105] In conclusion, AUC 0-last When comparing the values, the ranking of exposure after oral administration was raveximode HCl > raveximode Mes > raveximode Mao > raveximode.

Claims

1. A compound selected from the group consisting of HCl salt, methanesulfonic acid (mesylate) salt and malonate salt of the compound of formula (I). 【Chemistry 1】

2. 10. The compound of claim 1, wherein the compound is in solid form.

3. 3. The compound of claim 1 or 2, wherein the compound is in a crystalline form.

4. 4. The compound according to any one of claims 1 to 3, wherein the compound is selected from the group consisting of salts obtained by reaction of raveximide with an acid selected from HCl, malonic acid and methanesulfonic acid.

5. 5. The compound according to any one of claims 1 to 4, wherein the compound is an HCl salt in crystalline form, preferably in a crystalline form characterized by the following XRPD peaks: Table 1

6. 5. The compound according to any one of claims 1 to 4, wherein the compound is the methanesulfonate salt in crystalline form, preferably in a crystalline form characterized by the following XRPD peaks: Table 2

7. 5. The compound according to any one of claims 1 to 4, wherein the compound is a crystalline form of the malonate salt, preferably a crystalline form characterized by the following XRPD peaks: Table 3

8. The compound is a salt, and the salt is a) adding HCl, methanesulfonic acid or malonic acid as a suspension or solution to the free base of raveximide as a solid, suspension or solution to provide a solution or suspension of the corresponding salt; b) obtaining the salt as a solid by precipitation or crystallization, such as by cooling, evaporation of the solvent, addition of or to an antisolvent, or by addition of a co-crystallization agent, followed by filtration or centrifugation and, if necessary, purification of the salt.

9. The compound according to any one of claims 1 to 8, wherein said compound is a salt obtainable by the process described in the experimental section of this specification.

10. A compound according to any one of claims 1 to 9, wherein the compound has a solubility in water at room temperature of at least 5 mg / ml, for example 5 to 15 mg / ml.

11. A pharmaceutical composition comprising a compound according to any one of claims 1 to 10, and optionally a pharmaceutically acceptable excipient.

12. 1. A pharmaceutical composition for the treatment of a mammal, such as a human, suffering from or diagnosed with rheumatoid arthritis, preferably moderate rheumatoid arthritis, severe rheumatoid arthritis, or moderate to severe rheumatoid arthritis, comprising: A pharmaceutical composition comprising a compound according to any one of claims 1 to 10 as an active ingredient.

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