WO2023064519A1

WO2023064519A1 - Solid state forms of elacestrant and processes for preparation thereof

Info

Publication number: WO2023064519A1
Application number: PCT/US2022/046645
Authority: WO
Inventors: Lorena KORDIC; Valentina TRAVANCIC; Ivana LANDEKA; Nikolina JANTON
Original assignee: Teva Pharmaceuticals International Gmbh; Teva Pharmaceuticals Usa, Inc.
Priority date: 2021-10-14
Filing date: 2022-10-14
Publication date: 2023-04-20

Abstract

The present invention concerns a co-crystal of Elacestrant dihydrochloride and urea, its use in the preparation of another solid state form of Elecestrant or a salt thereof, and pharmaceutical compositions thereof.

Description

SOLID STATE FORMS OF ELACESTRANT AND PROCESSES FOR PREPARATION THEREOF

FIELD OF THE DISCLOSURE

[0001] The present disclosure encompasses solid state forms of Elacestrant and salts or cocrystals thereof, processes for preparation thereof, and pharmaceutical compositions thereof.

BACKGROUND OF THE DISCLOSURE

[0002] Elacestrant, (6R)-6-(2-(ethyl ((4-(2-(ethylamino) ethyl) phenyl)methylamino)-4- methoxyphenyl)- 5,6,7,8-Tetrahydronaphthalen-2-ol, has the following chemical structure:

[0003] Elacestrant is a selective estrogen receptor modulator and is particularly useful for the treatment of metastatic breast cancer.

[0004] The compound is described in International Publication No. WO 2004/058682. Elacestrant is described as a diHCl salt in International Publication No. WO 2016/176665 and specific crystalline forms of the di-HCl salt of Elacestrant are disclosed in International Publication Nos. WO 2018/0129419 and WO 2020/010216.

[0005] Polymorphism, the occurrence of different crystalline forms, is a property of some molecules and molecular complexes. A single molecule may give rise to a variety of polymorphs having distinct crystal structures and physical properties like melting point, thermal behaviors (e.g., measured by thermogravimetric analysis (“TGA”), or differential scanning calorimetry (“DSC”)), X-ray diffraction (XRD) pattern, infrared absorption fingerprint, and solid state (¹³C) NMR spectrum. One or more of these techniques may be used to distinguish different polymorphic forms of a compound. [0006] Different salts and solid state forms (including solvated forms) of an active pharmaceutical ingredient may possess different properties. Such variations in the properties of different salts and solid state forms and solvates may provide a basis for improving formulation, for example, by facilitating better processing or handling characteristics, changing the dissolution profile in a favorable direction, or improving stability (polymorph as well as chemical stability) and shelf-life. These variations in the properties of different salts and solid state forms may also offer improvements to the final dosage form, for instance, if they serve to improve bioavailability. Different salts and solid state forms and solvates of an active pharmaceutical ingredient may also give rise to a variety of polymorphs or crystalline forms, which may in turn provide additional opportunities to assess variations in the properties and characteristics of a solid active pharmaceutical ingredient.

[0007] Discovering new solid state forms and solvates of a pharmaceutical product may yield materials having desirable processing properties, such as ease of handling, ease of processing, storage stability, and ease of purification or as desirable intermediate crystal forms that facilitate conversion to other polymorphic forms. New solid state forms of a pharmaceutically useful compound can also provide an opportunity to improve the performance characteristics of a pharmaceutical product. It enlarges the repertoire of materials that a formulation scientist has available for formulation optimization, for example by providing a product with different properties, including a different crystal habit, higher crystallinity, or polymorphic stability, which may offer better processing or handling characteristics, improved dissolution profile, or improved shelf-life (chemi cal/phy si cal stability). For at least these reasons, there is a need for additional solid state forms (including solvated forms) of Elacestrant.

SUMMARY OF THE DISCLOSURE

[0008] The present disclosure provides crystalline polymorphs of Elacestrant, as well as cocrystals and/or salts of Elacestrant; processes for preparation thereof, and pharmaceutical compositions thereof. These crystalline polymorphs and crystalline salts and co-crystals can be used to prepare other solid state forms of Elacestrant, Elacestrant co-crystals, Elacestrant salts and their solid state forms.

[0009] The present disclosure also provides uses of the said solid state forms of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts in the preparation of other solid state forms of Elacestrant or Elacestrant co-crystals or salts thereof. [0010] The present disclosure also provides the said solid state forms of Elacestrant, cocrystals and/or Elacestrant salts for use in the preparation of other solid state forms of Elacestrant, or Elacestrant co-crystals or salts thereof.

[0011] The present disclosure provides crystalline polymorphs of Elacestrant, as well as cocrystals and/or salts of Elacestrant for use in the preparation of pharmaceutical compositions and/or formulations for use in medicine, including for the treatment of breast cancer.

[0012] The present disclosure also encompasses the use of crystalline polymorphs of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts of the present disclosure for the preparation of pharmaceutical compositions and/or formulations.

[0013] In another aspect, the present disclosure provides pharmaceutical compositions including crystalline polymorphs of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts according to the present disclosure.

[0014] In yet another embodiment, the present disclosure encompasses pharmaceutical formulations including any one or a combination of the crystalline polymorphs of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts or pharmaceutical compositions including the described crystalline polymorphs of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts and at least one pharmaceutically acceptable excipient.

[0015] The present disclosure includes processes for preparing the above mentioned pharmaceutical compositions. The processes include combining any one or a combination of the crystalline polymorphs of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts with at least one pharmaceutically acceptable excipient.

[0016] The crystalline polymorphs of Elacestrant, as well as co-crystals and/or salts of Elacestrant as defined herein and the pharmaceutical compositions or formulations of the crystalline polymorph of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts may be used as medicaments, such as for the treatment of breast cancer.

[0017] The present disclosure also provides methods of treating breast cancer, by administering a therapeutically effective amount of any one or a combination of the crystalline polymorphs of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts of the present disclosure, or at least one of the above pharmaceutical compositions, to a subject suffering from breast cancer, or otherwise in need of the treatment. [0018] The present disclosure also provides uses of crystalline polymorphs of Elacestrant, Elacestrant co-crystals and/or Elacestrant salts of the present disclosure, or at least one of the above pharmaceutical compositions, for the manufacture of medicaments for treating e.g., breast cancer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 shows a characteristic X-ray powder diffraction pattern (XRPD) of Elacestrant form B 1.

[0020] Figure 2 shows a characteristic X-ray powder diffraction pattern (XRPD) of Elacestrant monohydrochloride salt, form Hl.

[0021] Figure 3 shows a characteristic X-ray powder diffraction pattern (XRPD) of crystalline Elacestrant dihydrochloride; urea form A.

[0022] Figure 4 shows a characteristic X-ray powder diffraction pattern (XRPD) of crystalline Elacestrant dihydrochloride form 6.

[0023] Figure 5 shows a characteristic X-ray powder diffraction pattern (XRPD) of crystalline Elacestrant dihydrochloride form 7.

[0024] Figure 6 shows a characteristic X-ray powder diffraction pattern (XRPD) of crystalline Elacestrant dihydrochloride form 9.

[0025] Figure 7 shows a characteristic solid state ¹³C spectrum of Elacestrant dihydrochloride: urea cocrystal form A.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0026] The present disclosure provides crystalline polymorphs of Elacestrant, as well as cocrystals and/or salts of Elacestrant; processes for preparation thereof, and pharmaceutical compositions thereof.

[0027] Solid state properties of Elacestrant and crystalline polymorphs thereof can be influenced by controlling the conditions under which Elacestrant and crystalline polymorphs thereof are obtained in solid form.

[0028] A solid state form (or polymorph) may be referred to herein as polymorphically pure or as substantially free of any other solid state (or polymorphic) forms. As used herein in this context, the expression "substantially free of any other forms" will be understood to mean that the solid state form contains about 20% (w/w) or less, about 10% (w/w) or less, about 5% (w/w) or less, about 2% (w/w) or less, about 1% (w/w) or less, or about 0% of any other forms of the subject compound as measured, for example, by XRPD. Thus, a crystalline polymorph of Elacestrant described herein as substantially free of any other solid state forms would be understood to contain greater than about 80% (w/w), greater than about 90% (w/w), greater than about 95% (w/w), greater than about 98% (w/w), greater than about 99% (w/w), or about 100% of the subject crystalline polymorph of Elacestrant. In some embodiments of the disclosure, the described crystalline polymorph of Elacestrant may contain from about 1% to about 20% (w/w), from about 5% to about 20% (w/w), or from about 5% to about 10% (w/w) of one or more other crystalline polymorph of the same Elacestrant.

[0029] For example, polymorphically pure Form Hl of Elacestrant monohydrochloride is understood to mean that it is substantially free of other forms of Elacestrant monohydrochloride. Optionally, a solid state form (or polymorph), for example a co-crystal, referred to herein as polymorphically pure or as substantially free of any other solid state (or polymorphic) forms alternatively mean that the solid state form contains about 20% (w/w) or less, about 10% (w/w) or less, about 5% (w/w) or less, about 2% (w/w) or less, about 1% (w/w) or less, or about 0% of any other crystalline material as measured, for example, by XRPD. For example, a cocrystal of Elacestrant described herein as substantially free of any other solid state forms may contain about 20% (w/w) or less, about 10% (w/w) or less, about 5% (w/w) or less, about 2% (w/w) or less, about 1% (w/w) or less, or about 0% of any other crystalline material as measured, for example, by XRPD.

[0030] In any aspect or embodiment of the present disclosure, any of the solid state forms of Elacestrant described herein may be chemically pure or may be substantially free of any other compounds (impurities). As described herein, chemically pure Elacestrant described herein preferably has a purity of: > 95%, > 96%, > 97%, > 98%, > 98.5%, > 99%, > 99.2%, > 99.5%, > 99.8%, > 99.9%, or about 100% by weight, preferably as measured by HPLC.

[0031] Depending on which other crystalline polymorphs a comparison is made, the crystalline polymorphs of Elacestrant of the present disclosure may have advantageous properties selected from at least one of the following: chemical purity, flowability, solubility, dissolution rate, morphology or crystal habit, stability, such as chemical stability as well as thermal and mechanical stability with respect to polymorphic conversion, stability towards dehydration and/or storage stability, low content of residual solvent, a lower degree of hygroscopicity, flowability, and advantageous processing and handling characteristics such as compressibility and bulk density.

[0032] A solid state form, such as a crystal form or an amorphous form, may be referred to herein as being characterized by graphical data “as depicted in” or “as substantially depicted in” a Figure. Such data include, for example, powder X-ray diffractograms and solid state NMR spectra. As is well-known in the art, the graphical data potentially provides additional technical information to further define the respective solid state form (a so-called “fingerprint”) which cannot necessarily be described by reference to numerical values or peak positions alone. In any event, the skilled person will understand that such graphical representations of data may be subject to small variations, e.g., in peak relative intensities and peak positions due to certain factors such as, but not limited to, variations in instrument response and variations in sample concentration and purity, which are well known to the skilled person. Nonetheless, the skilled person would readily be capable of comparing the graphical data in the Figures herein with graphical data generated for an unknown crystal form and confirm whether the two sets of graphical data are characterizing the same crystal form or two different crystal forms. A crystal form of Elacestrant referred to herein as being characterized by graphical data “as depicted in” or “as substantially depicted in” a Figure will thus be understood to include any crystal forms of Elacestrant characterized with the graphical data having such small variations, as are well known to the skilled person, in comparison with the Figure.

[0033] As used herein, Elacestrant monohydrochloride refers to a salt form wherein the molar ratio of Elacestrant and HC1 is approximately 1, e.g., from about 0.7 to about 1.2, or about 0.9 to about 1.0, when taking account of experimental accuracy. Preferably, Elacestrant monohydrochloride refers to a salt form wherein the molar ratio of Elacestrant and HC1 is 1 : 1.

[0034] As used herein, Elacestrant diHCl or Elacestrant di-HCl or Elacestrant dihydrochloride refers to a salt form wherein the molar ratio of Elacestrant and HC1 is approximately 2, e.g., from about 1.7 to about 2.1, or from 1.8 to about 2.0, or about 1.9 to about 2.0.

[0035] As used herein, and unless stated otherwise, the term “anhydrous” in relation to crystalline forms of Elacestrant, relates to a crystalline form of Elacestrant which does not include any crystalline water (or other solvents) in a defined, stoichiometric amount within the crystal. Moreover, an “anhydrous” form would generally not contain more than 1% (w/w), of either water or organic solvents as measured for example by TGA.

[0036] The term "solvate," as used herein and unless indicated otherwise, refers to a crystal form that incorporates a solvent in the crystal structure. When the solvent is water, the solvate is often referred to as a "hydrate." The solvent in a solvate may be present in either a stoichiometric or in a non-stoichiometric amount.

[0037] Co-Crystal" or "Co-crystal" as used herein is defined as a crystalline material including two or more molecules in the same crystalline lattice and associated by non-ionic and non-covalent bonds. In some embodiments, the co-crystal includes two molecules which are in natural state.

[0038] As used herein, crystalline Elacestrant diHCl :urea is a distinct molecular species. Crystalline Elacestrant diHCl: urea may be a co-crystal of Elacestrant diHCl and urea. Alternatively crystalline Elacestrant diHCl: urea may be a salt. Preferably, Elacestrant diHCl: urea is a co-crystal. In embodiments the molar ratio between the active pharmaceutical ingredient (Elacestrant diHCl) and the coformer (urea) is between 1 : 2.

[0039] As used herein, the term "isolated" in reference to crystalline polymorph of Elacestrant, of the present disclosure corresponds to a crystalline polymorph of Elacestrant that is physically separated from the reaction mixture in which it is formed.

[0040] As used herein, unless stated otherwise, the XRPD measurements are taken using copper Kai radiation wavelength 1.54184 A. XRPD peaks reported herein are measured using CuK al radiation, = 1.54184 A, typically at a temperature of 25 ± 3°C.

[0041] As used herein, solid state ¹³C NMR measurements are measured at 500 MHz at a magic angle spinning frequency ®_r/27t = 11 kHz, preferably at a temperature of at 293 K ± 3 °C. [0042] A thing, e.g., a reaction mixture, may be characterized herein as being at, or allowed to come to “room temperature” or “ambient temperature”, often abbreviated as “RT.” This means that the temperature of the thing is close to, or the same as, that of the space, e.g., the room or fume hood, in which the thing is located. Typically, room temperature is from about 20°C to about 30°C, or about 22°C to about 27°C, or about 25°C.

[0043] The amount of solvent employed in a chemical process, e.g., a reaction or crystallization, may be referred to herein as a number of “volumes” or “vol” or “V.” For example, a material may be referred to as being suspended in 10 volumes (or 10 vol or 10V) of a solvent. In this context, this expression would be understood to mean milliliters of the solvent per gram of the material being suspended, such that suspending a 5 grams of a material in 10 volumes of a solvent means that the solvent is used in an amount of 10 milliliters of the solvent per gram of the material that is being suspended or, in this example, 50 mL of the solvent. In another context, the term "v/v" may be used to indicate the number of volumes of a solvent that are added to a liquid mixture based on the volume of that mixture. For example, adding solvent X (1.5 v/v) to a 100 ml reaction mixture would indicate that 150 mL of solvent X was added. [0044] A process or step may be referred to herein as being carried out "overnight." This refers to a time interval, e.g., for the process or step, that spans the time during the night, when that process or step may not be actively observed. This time interval is from about 8 to about 20 hours, or about 10-18 hours, in some cases about 16 hours.

[0045] As used herein, the term “reduced pressure” refers to a pressure that is less than atmospheric pressure. For example, reduced pressure is about 10 mbar to about 50 mbar.

[0046] As used herein and unless indicated otherwise, the term "ambient conditions" refer to atmospheric pressure and a temperature of 22-24°C.

[0047] The present disclosure includes a crystalline polymorph of Elacestrant, designated form Bl. Crystalline form Bl of Elacestrant may be characterized by data selected from one or more of the following: an X-ray powder diffraction pattern substantially as depicted in Figure 1; an X-ray powder diffraction pattern having peaks at 12.0, 13.5, 15.5, 16.1 and 17.7 degrees 2- theta ± 0.2 degrees 2-theta; and combinations of these data.

[0048] Crystalline form B 1 of Elacestrant may be further characterized by an X-ray powder diffraction pattern having peaks at 12.0, 13.5, 15.5, 16.1 and 17.7 degrees 2-theta ± 0.2 degrees 2-theta, and also having any one, two, three, four or five additional peaks selected from 8.3, 11.3, 14.1, 16.8 and 20.0 degrees 2-theta ± 0.2 degrees 2-theta.

[0049] In embodiments of the present disclosure, crystalline form Bl of Elacestrant is isolated.

[0050] Crystalline form Bl of Elacestrant may be anhydrous. In embodiments, crystalline form Bl may contain about 0.5 % to about 1 % of water by weight.

[0051] Crystalline form Bl may be polymorphically pure and/or chemically pure.

[0052] Crystalline form B 1 of Elacestrant may be characterized by each of the above characteristics alone or by all possible combinations, e.g., an XRPD pattern having peaks at 12.0, 13.5, 15.5, 16.1 and 17.7 degrees 2-theta ± 0.2 degrees 2-theta; an XRPD pattern as depicted in Figure 1; and combinations thereof.

[0053] The present disclosure includes a crystalline salt of Elacestrant monohydrochloride, designated form Hl. Crystalline form Hl of Elacestrant monohydrochloride may be characterized by data selected from one or more of the following: an X-ray powder diffraction pattern substantially as depicted in Figure 2; an X-ray powder diffraction pattern having peaks at 12.0, 12.9, 14.7, 17.3 and 21.1 degrees 2-theta ± 0.2 degrees 2-theta; and combinations of these data.

[0054] Crystalline salt of Elacestrant monohydrochloride form Hl may be further characterized by an X-ray powder diffraction pattern having peaks at 12.0, 12.9, 14.7, 17.3 and 21.1 degrees 2-theta ± 0.2 degrees 2-theta, and also having any one, two, three, four or five additional peaks selected from 10.6, 15.8, 21.6, 22.8 and 23.2 degrees 2-theta ± 0.2 degrees 2- theta.

[0055] In embodiments of the present disclosure, crystalline salt of Elacestrant monohydrochloride form Hl is isolated.

[0056] In any embodiment of the present disclosure, crystalline Elacestrant monohydrochloride form Hl may be polymorphically and/or chemically pure.

[0057] Crystalline salt of Elacestrant monohydrochloride form Hl may be a hydrate or an anhydrous form. Preferably Elacestrant monohydrochloride form Hl is an anhydrous form. [0058] Crystalline salt of Elacestrant monohydrochloride form Hl may be characterized by each of the above characteristics alone or by all possible combinations, e.g., an XRPD pattern having peaks at 12.0, 12.9, 14.7, 17.3 and 21.1 degrees 2-theta ± 0.2 degrees 2-theta; an XRPD pattern as depicted in Figure 2; and combinations thereof.

[0059] Crystalline Elacestrant monohydrochloride has been found to be stable upon heating up to 220°C.

[0060] The disclosure encompasses a crystalline form of Elacestrant diHCl: urea, which can be a co-crystal. The disclosure further encompasses a crystalline form of Elacestrant diHCl: urea designated form A. Crystalline form A of Elacestrant diHCl: urea may be characterized by data selected from one or more of the following: (a) an X-ray powder diffraction pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 ± 0.2 degrees 2-theta ± 0.2 degrees 2-theta; (b) a solid state ¹³C NMR spectrum having signals at about 162.9, 116.1, 103.5 and 12.1± 0.2 ppm; (c) a solid state ¹³C NMR spectrum having differences between the characteristic peaks at 162.9, 116.1, 103.5 and 12.1 ± 0.2 ppm and a reference peak at 9.6 ppm ± 0.2 ppm of 153.3, 106.5, 93.9 and 2.5 ± 0.1 ppm; (d) an X-ray powder diffraction pattern substantially as depicted in Figure 3; (e) a solid state ¹³C NMR spectrum substantially as depicted in Figure 7; and combinations of any of (a)- (e). Particularly, crystalline form A of Elacestrant diHCl: urea may be characterized by data selected from one or more of (a), (b) or (c). Crystalline form A of Elacestrant diHCl: urea according to the present disclosure may be characterized by (a) alone; (b) alone; (c) alone, (d) alone or (e) alone. Alternatively crystalline form A of Elacestrant diHCl: urea according to the present disclosure may be characterized by: (a) in combination with (b); (a) in combination with (c); or a combination of (a), (b) and (c).

[0061] Crystalline form A of Elacestrant diHCl: urea may be further characterized by an X- ray powder diffraction pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 degrees 2-theta ± 0.2 degrees 2-theta, and also having any one, two, three, four or five additional peaks selected from 10.4, 19.8, 21.3, 21.8 and 26.2 degrees 2-theta ± 0.2 degrees 2-theta.

[0062] Crystalline form A of Elacestrant diHCl: urea according to the present disclosure may be characterized by an X-ray powder diffraction pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 degrees 2-theta ± 0.2 degrees 2-theta, and also having any one, two, three, four or five additional peaks selected from 10.4, 19.8, 21.3, 21.8 and 26.2 degrees 2-theta ± 0.2 degrees 2- theta; and one or both of data selected from: a solid state ¹³C NMR spectrum having signals at about 162.9, 116.1, 103.5 and 12.1± 0.2 ppm, and a solid state ¹³C NMR spectrum having differences between the characteristic peaks at 162.9, 116.1, 103.5 and 12.1 ± 0.2 ppm and a reference peak at 9.6 ppm ± 0.2 ppm of 153.3, 106.5, 93.9 and 2.5 ± 0.1 ppm.

[0063] Crystalline form A of Elacestrant diHCl: urea may be alternatively characterized by an X-ray powder diffraction pattern having peaks at 9.9, 10.4, 12.3, 17.2, 19.8, 21.3, 21.8, 23.2 and 26.2.

[0064] According to any embodiment of the present disclosure, crystalline form A of Elacestrant diHCl: urea is a co-crystal. Preferably, crystalline form A of Elacestrant diHCl: urea may contain Elacestrant diHCl :urea in a molar ratio of about 1 :2.

[0065] In embodiments of the present disclosure, crystalline form A of Elacestrant diHCl: urea is isolated. [0066] According to any embodiment of the present disclosure, the crystalline form of Elacestrant diHCl: urea, preferably Form A as defined herein, is anhydrous. More preferably, the crystalline form of Elacestrant diHCl: urea, preferably Form A as defined according to any embodiment of the disclosure may contain about 0.5 % to about 1 % of water by weight.

[0067] Crystalline form A of Elacestrant diHCl; urea may be polymorphically pure and/or chemically pure.

[0068] Crystalline form A of Elacestrant diHCl: urea may be characterized by each of the above characteristics alone or by all possible combinations, e.g., an XRPD pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 degrees 2-theta ± 0.2 degrees 2-theta; an XRPD pattern as depicted in Figure 3; and combinations thereof.

[0069] The disclosure further encompasses a crystalline form of Elacestrant diHCl, designated form 9. Crystalline form 9 of Elacestrant dihydrochloride may be characterized by data selected from one or more of the following: an X-ray powder diffraction pattern substantially as depicted in Figure 6; an X-ray powder diffraction pattern having peaks at 10.2, 14.9 and 23.6 degrees two-theta ± 0.2 degrees two-theta; and combinations of these data.

[0070] Crystalline form 9 of Elacestrant dihydrochloride may be further characterized by an X-ray powder diffraction pattern having peaks at 10.2, 14.9 and 23.6 degrees two-theta ± 0.2 degrees two-theta , and also having any one, two, three, four or five additional peaks selected from 9.3, 12.2, 16.2, 21.4 and 22.3 degrees two-theta ± 0.2 degrees 2-theta.

[0071] Alternatively, Crystalline Form 9 of Elacestrant dihydrochloride may be characterized by an X-ray powder diffraction pattern having peaks at 8.2, 10.2, 14.9, 18.7 and

23.6 degrees 2-theta ± 0.2 degrees 2-theta, Crystalline Form 9 of Elacestrant dihydrochloride may be further characterized by an X-ray powder diffraction pattern having peaks 8.2, 10.2, 14.9,

18.7 and 23.6 degrees 2-theta ± 0.2 degrees 2-theta and also having any one, two, three, four or five additional peaks selected from 9.3, 12.2, 16.2, 21.4 and 22.3 degrees 2-theta ± 0.2 degrees 2- theta.

[0072] Crystalline Form 9 of Elacestrant dihydrochloride may be characterized by an X-ray powder diffraction pattern having peaks at 8.2, 9.3, 10.2, 12.2, 14.9, 16.2, 18.7, 21.4, 22.3 and 23.6 degrees 2-theta ± 0.2 degrees 2-theta.

[0073] In embodiments of the present disclosure, crystalline form 9 of Elacestrant dihydrochloride is isolated. [0074] Crystalline form 9 of Elacestrant dihydrochloride may be characterized by each of the above characteristics alone or by all possible combinations, e.g., an XRPD pattern having peaks at 8.2, 10.2, 14.9, 18.7 and 23.6 degrees 2-theta ± 0.2 degrees 2-theta; an XRPD pattern as depicted in Figure 6; and combinations thereof.

[0075] In any embodiment of the present disclosure, crystalline Elacestrant dihydrochloride form 9 may be polymorphically and/or chemically pure.

[0076] The disclosure further encompasses Elacestrant dihydrochloride form 6. Crystalline form 6 of Elacestrant dihydrochloride may be characterized by figure 4. In one embodiment crystalline form 6 is a DMSO (dimethylsulfoxide) solvate.

[0077] In any embodiment of the present disclosure, crystalline Elacestrant dihydrochloride form 6 may be polymorphically and/or chemically pure.

[0078] The disclosure further encompasses Elacestrant dihydrochloride form 7. Crystalline form 7 of Elacestrant dihydrochloride may be characterized by figure 5. In one embodiment crystalline form 7 is a 1 -propanol solvate.

[0079] In any embodiment of the present disclosure, crystalline Elacestrant dihydrochloride form 7 may be polymorphically and/or chemically pure.

[0080] The above crystalline forms can be used to prepare other crystalline polymorphs of Elacestrant, Elacestrant salts or co-crystals and their solid state forms.

[0081] The present disclosure provides the above described crystalline polymorphs of Elacestrant, Elacestrant salts or co-crystals for use in the preparation of pharmaceutical compositions comprising Elacestrant, Elacestrant salts or co-crystals and/or crystalline polymorphs thereof.

[0082] The present disclosure also encompasses the use of crystalline polymorphs of Elacestrant, Elacestrant salts or co-crystals of the present disclosure for the preparation of pharmaceutical compositions of crystalline polymorph Elacestrant, Elacestrant salts or cocrystals and/or crystalline polymorphs thereof.

[0083] The present disclosure includes processes for preparing the above mentioned pharmaceutical compositions. The processes include combining any one or a combination of the crystalline polymorphs of Elacestrant, Elacestrant salts or co-crystals of the present disclosure with at least one pharmaceutically acceptable excipient. [0084] The present disclosure further includes a crystalline polymorph of Elacestrant, Elacestrant salt or co-crystal of the present disclosure for use as a medicament, preferably wherein the medicament is for the treatment of breast cancer.

[0085] The present disclosure further provides a method of treating of breast cancer comprising administering a therapeutically effective amount of a crystalline polymorph of Elacestrant, Elacestrant salt or co-crystal of the present disclosure to a subject in need of treatment.

[0086] Pharmaceutical combinations or formulations of the present disclosure contain any one or a combination of the solid state forms of Elacestrant, Elacestrant salts or co-crystals of the present disclosure. In addition to the active ingredient, the pharmaceutical formulations of the present disclosure can contain one or more excipients. Excipients are added to the formulation for a variety of purposes.

[0087] Diluents increase the bulk of a solid pharmaceutical composition, and can make a pharmaceutical dosage form containing the composition easier for the patient and caregiver to handle. Diluents for solid compositions include, for example, microcrystalline cellulose (e.g. Avicel®), microfine cellulose, lactose, starch, pregelatinized starch, calcium carbonate, calcium sulfate, sugar, dextrates, dextrin, dextrose, dibasic calcium phosphate dihydrate, tribasic calcium phosphate, kaolin, magnesium carbonate, magnesium oxide, maltodextrin, mannitol, polymethacrylates (e.g. Eudragit®), potassium chloride, powdered cellulose, sodium chloride, sorbitol, and talc.

[0088] Solid pharmaceutical compositions that are compacted into a dosage form, such as a tablet, can include excipients whose functions include helping to bind the active ingredient and other excipients together after compression. Binders for solid pharmaceutical compositions include acacia, alginic acid, carbomer (e.g. carbopol), carboxymethylcellulose sodium, dextrin, ethyl cellulose, gelatin, guar gum, hydrogenated vegetable oil, hydroxyethyl cellulose, hydroxypropyl cellulose (e.g. Klucel®), hydroxypropyl methyl cellulose (e.g. Methocel®), liquid glucose, magnesium aluminum silicate, maltodextrin, methylcellulose, polymethacrylates, povidone (e.g. Kollidon®, Plasdone®), pregelatinized starch, sodium alginate, and starch.

[0089] The dissolution rate of a compacted solid pharmaceutical composition in the patient's stomach can be increased by the addition of a disintegrant to the composition. Disintegrants include alginic acid, carboxymethylcellulose calcium, carboxymethylcellulose sodium (e.g. Ac- Di-Sol®, Primellose®), colloidal silicon dioxide, croscarmellose sodium, crospovidone (e.g. Kollidon®, Polyplasdone®), guar gum, magnesium aluminum silicate, methyl cellulose, microcrystalline cellulose, polacrilin potassium, powdered cellulose, pregelatinized starch, sodium alginate, sodium starch glycolate (e.g. Explotab®), and starch.

[0090] Glidants can be added to improve the flowability of a non-compacted solid composition and to improve the accuracy of dosing. Excipients that can function as glidants include colloidal silicon dioxide, magnesium trisilicate, powdered cellulose, starch, talc, and tribasic calcium phosphate.

[0091] When a dosage form such as a tablet is made by the compaction of a powdered composition, the composition is subjected to pressure from a punch and dye. Some excipients and active ingredients have a tendency to adhere to the surfaces of the punch and dye, which can cause the product to have pitting and other surface irregularities. A lubricant can be added to the composition to reduce adhesion and ease the release of the product from the dye. Lubricants include magnesium stearate, calcium stearate, glyceryl monostearate, glyceryl palmitostearate, hydrogenated castor oil, hydrogenated vegetable oil, mineral oil, polyethylene glycol, sodium benzoate, sodium lauryl sulfate, sodium stearyl fumarate, stearic acid, talc, and zinc stearate.

[0092] Flavoring agents and flavor enhancers make the dosage form more palatable to the patient. Common flavoring agents and flavor enhancers for pharmaceutical products that can be included in the composition of the present disclosure include maltol, vanillin, ethyl vanillin, menthol, citric acid, fumaric acid, ethyl maltol, and tartaric acid.

[0093] Solid and liquid compositions can also be dyed using any pharmaceutically acceptable colorant to improve their appearance and/or facilitate patient identification of the product and unit dosage level.

[0094] In liquid pharmaceutical compositions of the present invention, Elacestrant, Elacestrant salts or co-crystals and any other solid excipients can be dissolved or suspended in a liquid carrier such as water, vegetable oil, alcohol, polyethylene glycol, propylene glycol, or glycerin.

[0095] Liquid pharmaceutical compositions can contain emulsifying agents to disperse uniformly throughout the composition an active ingredient or other excipient that is not soluble in the liquid carrier. Emulsifying agents that can be useful in liquid compositions of the present invention include, for example, gelatin, egg yolk, casein, cholesterol, acacia, tragacanth, chondrus, pectin, methyl cellulose, carbomer, cetostearyl alcohol, and cetyl alcohol.

[0096] Liquid pharmaceutical compositions of the present invention can also contain a viscosity enhancing agent to improve the mouth-feel of the product and/or coat the lining of the gastrointestinal tract. Such agents include acacia, alginic acid bentonite, carbomer, carboxymethylcellulose calcium or sodium, cetostearyl alcohol, methyl cellulose, ethylcellulose, gelatin guar gum, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, maltodextrin, polyvinyl alcohol, povidone, propylene carbonate, propylene glycol alginate, sodium alginate, sodium starch glycolate, starch tragacanth, xanthan gum and combinations thereof.

[0097] Sweetening agents such as sorbitol, saccharin, sodium saccharin, sucrose, aspartame, fructose, mannitol, and invert sugar can be added to improve the taste.

[0098] Preservatives and chelating agents such as alcohol, sodium benzoate, butylated hydroxyl toluene, butylated hydroxyanisole, and ethylenediamine tetraacetic acid can be added at levels safe for ingestion to improve storage stability.

[0099] According to the present disclosure, a liquid composition can also contain a buffer such as gluconic acid, lactic acid, citric acid, or acetic acid, sodium gluconate, sodium lactate, sodium citrate, or sodium acetate. Selection of excipients and the amounts used can be readily determined by the formulation scientist based upon experience and consideration of standard procedures and reference works in the field.

[00100] The solid compositions of the present disclosure include powders, granulates, aggregates, and compacted compositions. The dosages include dosages suitable for oral, buccal, rectal, parenteral (including subcutaneous, intramuscular, and intravenous), inhalant, and ophthalmic administration. Although the most suitable administration in any given case will depend on the nature and severity of the condition being treated, in embodiments the route of administration is oral. The dosages can be conveniently presented in unit dosage form and prepared by any of the methods well-known in the pharmaceutical arts.

[00101] Dosage forms include solid dosage forms like tablets, powders, capsules, suppositories, sachets, troches, and lozenges, as well as liquid syrups, suspensions, and elixirs. [00102] The dosage form of the present disclosure can be a capsule containing the composition, such as a powdered or granulated solid composition of the disclosure, within either a hard or soft shell. The shell can be made from gelatin and optionally contain a plasticizer such as glycerin and/or sorbitol, an opacifying agent and/or colorant.

[00103] The active ingredient and excipients can be formulated into compositions and dosage forms according to methods known in the art.

[00104] A composition for tableting or capsule filling can be prepared by wet granulation. In wet granulation, some or all of the active ingredients and excipients in powder form are blended and then further mixed in the presence of a liquid, typically water, that causes the powders to clump into granules. The granulate is screened and/or milled, dried, and then screened and/or milled to the desired particle size. The granulate can then be tableted, or other excipients can be added prior to tableting, such as a glidant and/or a lubricant.

[00105] A tableting composition can be prepared conventionally by dry blending. For example, the blended composition of the actives and excipients can be compacted into a slug or a sheet and then comminuted into compacted granules. The compacted granules can subsequently be compressed into a tablet.

[00106] As an alternative to dry granulation, a blended composition can be compressed directly into a compacted dosage form using direct compression techniques. Direct compression produces a more uniform tablet without granules. Excipients that are particularly well suited for direct compression tableting include microcrystalline cellulose, spray dried lactose, dicalcium phosphate dihydrate, and colloidal silica. The proper use of these and other excipients in direct compression tableting is known to those in the art with experience and skill in particular formulation challenges of direct compression tableting.

[00107] A capsule filling of the present disclosure can include any of the aforementioned blends and granulates that were described with reference to tableting, but they are not subjected to a final tableting step.

[00108] A pharmaceutical formulation of Elacestrant, Elacestrant salts or co-crystals can be administered. Elacestrant, Elacestrant salts or co-crystals may be formulated for administration to a mammal, in embodiments to a human, by injection. Elacestrant, Elacestrant salts or cocrystals can be formulated, for example, as a viscous liquid solution or suspension, such as a clear solution, for injection. The formulation can contain one or more solvents. A suitable solvent can be selected by considering the solvent's physical and chemical stability at various pH levels, viscosity (which would allow for syringeability), fluidity, boiling point, miscibility, and purity. Suitable solvents include alcohol USP, benzyl alcohol NF, benzyl benzoate USP, and Castor oil USP. Additional substances can be added to the formulation such as buffers, solubilizers, and antioxidants, among others. Ansel et al., Pharmaceutical Dosage Forms and Drug Delivery Systems, 7th ed.

[00109] The crystalline polymorphs of Elacestrant, Elacestrant salts or co-crystals and the pharmaceutical compositions and/or formulations of Elacestrant, Elacestrant salts or co-crystals of the present disclosure can be used as medicaments, in embodiments in the treatment of breast cancer.

[00110] Having thus described the disclosure with reference to particular preferred embodiments and illustrative examples, those in the art can appreciate modifications to the disclosure as described and illustrated that do not depart from the spirit and scope of the disclosure as disclosed in the specification. The Examples are set forth to aid in understanding the disclosure but are not intended to, and should not be construed to limit its scope in any way.

[00111] Further aspects and embodiments of the present disclosure are set out in the numbered clauses below:

1. A crystalline form, designated form Bl, which is characterized by data selected from one or more of the following: a. an XRPD pattern having peaks at 12.0, 13.5, 15.5, 16.1 and 17.7 degrees 2-theta ± 0.2 degrees 2-theta; b. an XRPD pattern as depicted in Figure 1; and c. combination of these data.

2. A crystalline product according to Clause 1, designated form Bl, characterized by the XRPD pattern having peaks at 12.0, 13.5, 15.5, 16.1 and 17.7 degrees 2-theta ± 0.2 degrees 2-theta and also having one, two, three or four additional peaks selected from 8.3, 11.3, 14.1, 16.8 and 20.0 degrees two theta ± 0.2 degrees two theta.

3. A crystalline form, designated form Bl, according to any one of Clauses 1 or 2 wherein the form is anhydrous.

4. A crystalline product according to any one of Clauses 1-3 designated form Bl which contains: no more than about 20%, no more than about 10%, no more than about 5%, no more than about 2%, no more than about 1% or about 0% of any other crystalline forms of Elacestrant. A crystalline product according to any one of Clauses 1-3 or 4, designated form Bl, which contains: no more than about 20%, no more than about 10%, no more than about 5%, no more than about 2%, no more than about 1% or about 0% of amorphous Elacestrant. Elacestrant monohydrochloride. Crystalline Elacestrant monohydrochloride. Amorphous Elacestrant monohydrochloride. Crystalline Elacestrant monohydrochloride, designated form Hl which is characterized by data selected from one or more of the following: a. an XRPD pattern having peaks at 12.0, 12.9, 14.7, 17.3 and 21.1 degrees 2-theta ± 0.2 degrees 2-theta; b. an XRPD pattern as depicted in Figure 2; and c. combination of these data. A crystalline product according to Clause 9, designated form Hl, characterized by the XRPD pattern having peaks at 12.0, 12.9, 14.7, 17.3 and 21.1 degrees 2-theta ± 0.2 degrees 2-theta, and also having one, two, three or four additional peaks selected from 10.6, 15.8, 21.6, 22.8 and 23.2 degrees two theta ± 0.2 degrees two theta. A crystalline form, designated form Hl, according to any of Clauses 9 or 10 wherein the form is anhydrous or a hydrate, preferably anhydrous. A crystalline product according to any one of Clauses 9-11 designated form Hl which contains: no more than about 20%, no more than about 10%, no more than about 5%, no more than about 2%, no more than about 1% or about 0% of any other crystalline forms of Elacestrant. A crystalline product according to any one of Clauses 9-12, designated form Hl, which contains: no more than about 20%, no more than about 10%, no more than about 5%, no more than about 2%, no more than about 1% or about 0% of amorphous Elacestrant. Crystalline Elacestrant dihydrochloride: urea. Crystalline Elacestrant dihydrochloride: urea which is a co-crystal. Crystalline Elacestrant dihydrochloride: urea which is a salt. A crystalline product according to any one of Clauses 14-16, designated form A, which is characterized by data selected from one or more of the following: a. an XRPD pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 degrees 2- theta ± 0.2 degrees 2-theta; b. an XRPD pattern as depicted in Figure 3; and c. combinations of these data. A crystalline product according to any one of Clauses 14-17, designated form A, characterized by the XRPD pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 degrees 2-theta ± 0.2 degrees 2-theta, and also having one, two, three or four additional peaks selected from 10.4, 19.8, 21.3, 21.8 and 26.2 degrees two theta ± 0.2 degrees two theta. A crystalline product according to any of Claims 1 to 18, which has a purity of at least 95%, at least 96%, at least 97%, at least 98%, at least 98.5%, at least 99%, at least 99.2%, at least 99.5%, at least 99.8%, at least 99.9%, or about 100%. Use of a crystalline product according to any of Claims 1 to 19, in the preparation of another solid state form of Elacestrant, or Elacestrant salt or solid state form thereof. A process for preparing another solid state form of Elacestrant or Elacestrant salt or a solid state form thereof comprising preparing a crystalline product according to any of Claims 1 to 19, and converting it to another solid state form of Elacestrant or Elacestrant salt or a solid state form thereof. A pharmaceutical composition comprising a crystalline product according to any of Claims 1 to 19. Use of a crystalline product according to any of Claims 1 to 19 for the preparation of a pharmaceutical composition and/or pharmaceutical formulation. A pharmaceutical formulation comprising a crystalline product according to any of Claims 1 to 19, or a pharmaceutical composition of Claim 22, with at least one pharmaceutically acceptable excipient. A crystalline product according to any of Claims 1 to 19, a pharmaceutical composition according to Claim 22, or a pharmaceutical formulation according to Claim 24, for use as a medicament. A crystalline product according to any of Claims 1 to 19, for use according to Claim 25, wherein the medicament is for the treatment of breast cancer A method of treating of breast cancer comprising administering a therapeutically effective amount of a crystalline product according to any of Claims 1 to 19, a pharmaceutical composition according to Claim 22, or a pharmaceutical formulation according to Claim 24, to a subject in need of treatment.

Powder X-ray Diffraction ("XRPD") method

[00112] The sample was powdered in a mortar and pestle and applied directly on a silicon plate holder. The X-ray powder diffraction pattern was measured with a Philips X'Pert PRO X- ray powder diffractometer, equipped with Cu irradiation source =1.54184 A (Angstrom), X’Celerator (2.022° degrees 2theta) detector. Scanning parameters: angle range: 3-40 degrees 2theta, step size 0.0167, time per step 37 s, and continuous scan. ss-¹³C NMR measurement method

[00113] Solid-state ¹³C NMR spectra is measured at 11.7 T using a Bruker Avance III HD 500 US/WB NMR spectrometer (Karlsruhe, Germany, 2013) with a 4-mm probe head. The ¹³C CP/MAS NMR spectra employing cross-polarization are acquired using the standard cross- polarization pulse scheme at spinning frequency of 11 kHz. The dipolar decoupling SPINAL64 is applied during the data acquisition. The number of scans is set for the signal -to-noise ratio SINO reaches at least the value ca. 50. The ¹³C scale is referenced to a-glycine (176.03 ppm for ¹³C. Frictional heating of the spinning samples is compensated by active cooling, and the temperature calibration is performed with Pb(NO3)2. The NMR spectrometer is always completely calibrated and all experimental parameters are carefully optimized prior the recording of the spectra. Magic angle is set using KBr during the standard optimization procedure and homogeneity of magnetic field is optimized using adamantane sample (resulting line-width at half-height AVI/2 was less than 3.5 Hz at 250 ms of acquisition time).

EXAMPLES

Preparation of starting materials

[00114] Elacestrant can be prepared according to methods known from the literature, for example as described in International Publication No. WO 2004/058682. Elacestrant di-HCl can be prepared by methods as described in International Publication No. WO 2018/0129419. Example 1. Preparation of Elacestrant base form Bl

[00115] Elacestrant (20 mg) was dissolved in Acetonitrile (0.5 ml) by heating up to about 46°C until complete dissolution. The solution was left to cool down followed by evaporation at room temperature until crystallization occurred after approximately 24 hours. The solid was filtered and analyzed by XRPD and identified as Elacestrant form Bl (Figure 1).

Example 2. Preparation of Elacestrant monohydrochloride salt

[00116] Elacestrant form Bl (100 mg) was dissolved in a mixture of ethanokethyl acetate (1 :3, 2 ml) at about 46 °C. After the solution was left to cool to room temperature, hydrochloric acid (0.2 ml, 1.1 eq.) was added. Next, ethyl acetate (8 ml) was added dropwise. Crystallization occurred and suspension was vacuum filtered. Sample was analyzed by XRPD and Elacestrant monohydrochloride salt, form Hl, was obtained (Figure 2).

Example 3. Preparation of Elacestrant diHCl;Urea

[00117] Elacestrant diHCl (1,170 mg) and Urea (249.8 mg, 2 eq.) were suspended in acetonitrile (10 ml) at room temperature. After 24 hours, the suspension was vacuum filtered, analyzed by XRPD and identified as Elacestrant diHCl and urea co-crystal. The XRPD pattern is presented in Figure 3.

Example 4. Preparation of Elacestrant diHCl;Urea form A

[00118] Urea (228mg, 10 eq) was dissolved in 96% Ethanol solution (3mL), at 65 °C. Then 200 mg of Elacestrant diHCl was added solution was obtained. The solution was cooled down to room temperature, during which the material started to crystalize. The obtained suspension was vacuum filtered and analyzed by XRPD. Elacestrant diHCl and urea co-crystal form A was obtained

Example 5. Preparation of Elacestrant Dihydrochloride form 6

[00119] Elacestrant diHCl (0.66 gram) was dissolved in an anhydrous dimethylsulfoxide (2 mL) at about 58°C in inert atmosphere (argon). Then, solution was left to cool to room temperature and anhydrous methyl isobutyl ketone was added dropwise (6 mL). Obtained suspension was stirred overnight at room temperature in inert atmosphere (argon). Next day it was filtered off over blue ribbon filter paper, under vacuum. Then dried in oven, under vacuum at 60°C for 5 hours. Material was analyzed by XRPD and Elacestrant dihydrochloride salt, form 6, was obtained (Figure 4).

Example 6. Preparation of Elacestrant Dihydrochloride form 7

[00120] Elacestrant base (1 gram) was dissolved in 1-propanol (20 mL) at 55 °C. Concentrated hydrochloric acid solution (1.7 mL) was added, after which heating was discontinued; solution was left to cool to room temperature and stirred overnight. The obtained precipitate was vacuum filtered and analyzed by XRPD. Elacestrant dihydrochloride salt, form 7, was obtained (Figure 5).

Example 7. Preparation of Amorphous Elacestrant Dihydrochloride

[00121] Elacestrant diHCl (1.5 gram) was dissolved in methanol (20mL) at 50°C. Obtained solution was hot filtrated over black ribbon filter paper and placed on rotary evaporator, where it was continuously evaporated. The obtained powder was analyzed by XRPD and indicated that Amorphous Elacestrant diHCl was obtained.

Example 8. Preparation of Elacestrant Dihydrochloride form 9

[00122] Amorphous Elacestrant diHCl (0.2 gram) was exposed to 75% of relative humidity (“RH”) on 40°C for 6 days. Material was analyzed by XRPD and Elacestrant dihydrochloride salt, form 9, was obtained, as presented in Figure 6.

Example 9. Solubility of Elacestrant diHCl: urea

[00123] Suspensions of Elacestrant dihydrochloride forms (100 mg), in 9 mL of buffer and water were stirred at 37°C for 24 hours (shaker; 160 rpm). The concentration of Elacestrant was determined by HPLC according to corresponding standard. Solubility class was defined according to European Pharmacopoeia criteria, i.e.: <0.1 mg/mL - practically insoluble; 0.1-1 mg/mL - very slightly soluble; 1-10 mg/mL - slightly soluble; 10-33 mg/mL - sparingly soluble; 33-100 mg/mL - soluble; 100-1000 mg/mL - freely soluble. The obtained results are shown in Table 1 :

Table 1

[00124] The results show that Elacestrant diHCl: urea co-crystal has a significantly higher solubility at physiologically relevant pH values, compared with Elacestrant dihydrochloride form 1 and Elacestrant dihydrochloride form IB.

Example 10. Stability and stress tests for Elacestrant dihydrochloride: urea co-crystal

[00125] Hygroscopicity experiments at stress condition 20-100% RH / 25°C for 7 days and 20-80% RH / 25°C for 30 days, show that form A is polymorphically stable. Form A is also stable to strong grinding.

[00126] Solvent drop grinding were done on the crystalline material, as well the crystalline material in the presence of acetone, ethanol, or isopropanol. About 20 mg of the sample is placed in a mortar and ground with a pestle for 2 minutes. The solvents, when used, were added to the crystalline material before grinding, in a volume of 10 microlitres.

[00127] Sauna experiments were conducted by exposure of about 20 mg of a sample in a tube, which is placed in a bottle containing acetone, ethanol or isopropanol, and sealed for 7 days.

[00128] As indicated below, Elacestrant dihydrochloride: urea co-crystal is stable to the tests as shown in Table 2:

Table 2

[00129] As disclosed in W02020010216, Figure 1, Forms 1-3 of Elacestrant dihydrochloride interconvert depending on temperature and relative humidity. Form 1 converts to Form 3 upon exposure to > 90%RH. At less than 40% RH, Form 3, which is a hydrate, converts to an anhydrous Form 2. At greater than 40% RH, Form 2 converts to hydrate Form 3.

[00130] Liquid assisted grinding results for forms 1 and IB as disclosed in WO2018129419 and W02020010216, respectively, in 2-propanol, acetone and ethanol, are presented below in Table 3:

*VLC - very low crystallinity; LC - low crystallinity

Table 3

[00131] As can be seen from the data in Table 3, Elacestrant dihydrochloride: urea cocrystal exhibits enhanced polymorphic stability compared with Elacestrant dihydrochloride forms 1 and IB.

Example 11. Stability and stress tests for Elacestrant monohydrochloride form Hl

[00132] Elacestrant monohydrochloride form Hl is polymorphically stable on all tested stress conditions as described in Example 9, as well as to heating, as shown in Table 4 below:

Table 4

[00133] As can be seen from the data in Table 4, Elacestrant monohydrochloride form Hl exhibits enhanced polymorphic stability compared with Elacestrant dihydrochloride forms 1 and IB.

Example 12. Stability of Elacestrant Form Bl

[00134] Elacestrant Form Bl was observed to be stable to heating up to 250°C. DVS experiments further show that Elacestrant form Bl is stable at high relative humidity. In contrast, Elacestrant dihydrochloride form 1 and Elacestrant dihydrochloride form IB both show a greater hygroscopicity under the same conditions (Table 5):

Table 5

Claims

28 CLAIMS:

1. A co-crystal of Elacestrant dihydrochloride and urea.

2. A co-crystal of Elacestrant dihydrochloride and urea according to Claim 1, which is designated form A, and which is characterized by data selected from one or more of the following: (a) an XRPD pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 degrees 2- theta ± 0.2 degrees 2-theta; (b) a solid state ¹³C NMR spectrum having signals at about 162.9, 116.1, 103.5 and 12.1± 0.2 ppm; (c) a solid state ¹³C NMR spectrum having differences between the characteristic peaks at 162.9, 116.1, 103.5 and 12.1 ± 0.2 ppm and a reference peak at 9.6 ppm ± 0.2 ppm of 153.3, 106.5, 93.9 and 2.5 ± 0.1 ppm.

3. A co-crystal according to claim 1 or claim 2 which is characterized by the XRPD pattern having peaks at 9.9, 12.3, 17.2, 23.2 and 24.8 degrees 2-theta ± 0.2 degrees 2-theta, and also having one, two, three or four additional peak selected from 10.4, 19.8, 21.3, 21.8 and 26.2 degrees two theta ± 0.2 degrees two theta; or which is characterized by an XRPD pattern having peaks at 9.9, 10.4, 12.3, 17.2, 19.8, 21.3, 21.8, 23.2 and 26.2.

4. A co-crystal according to any of Claims 1-3, which is further characterized by an XRPD pattern substantially as depicted in figure 3, and/or a solid state ¹³C NMR spectrum substantially as depicted in figure 7.

5. A co-crystal according to any of claims 1-4 wherein the molar ratio of Elacestrant dihydrochloride and urea is about 1 :2.

6. A co-crystal according to any of Claims 1 to 5, which is polymorphically pure, optionally wherein the co-crystal contains: about 20% or less, about 10% or less, about 5% or less, about 2% or less, about 1% or less, or about 0% of any other crystalline material; optionally wherein the co-crystal contains: about 20% or less, about 10% or less, about 5% or less, about 2% or less, about 1% or less, or about 0% of any other solid state forms of Elacestrant or Elacestrant dihydrochloride or Elacestrant dihydrochloride and urea; and preferably containing: greater than about 80%, greater than 90%, greater than about 95%, %, greater than about 98% or less, %, greater than about 99% or less, or about 100% of the co-crystal of Elacestrant dihydrochloride and urea. A co-crystal according to any of Claims 1 to 6, which has a chemical purity of at least 95%, at least 96%, at least 97%, at least 98%, at least 98.5%, at least 99%, at least 99.2%, at least 99.5%, at least 99.8%, at least 99.9%, or about 100%. Use of a co-crystal according to any one of Claims 1 to 7, in the preparation of another solid state form of Elacestrant, or Elacestrant salt or solid state form thereof. A process for preparing another solid state form of Elacestrant or Elacestrant salt or a solid state form thereof comprising preparing a co-crystal according to any one of Claims 1 to 7, and converting it to another solid state form of Elacestrant or Elacestrant salt or a solid state form thereof. A pharmaceutical composition comprising a co-crystal according to any of Claims 1 to 7. Use of a co-crystal according to any of Claims 1 to 7 for the preparation of a pharmaceutical composition and/or pharmaceutical formulation. A pharmaceutical formulation comprising a co-crystal according to any of Claims 1 to 7, or a pharmaceutical composition of Claim 10, with at least one pharmaceutically acceptable excipient. A co-crystal according to any one of Claims 1 to 7, a pharmaceutical composition according to Claim 10, or a pharmaceutical formulation according to Claim 12, for use as a medicament. A co-crystal according to any of Claims 1 to 7, for use according to Claim 13, wherein the medicament is for the treatment of breast cancer A method of treating of breast cancer comprising administering a therapeutically effective amount of a co-crystal according to any of Claims 1-7, a pharmaceutical composition according to Claim 10, or a pharmaceutical formulation according to Claim 12, to a subject in need of treatment.