HK1220965B - Novel abexinostat salt, associated crystalline form, preparation method thereof and the pharmaceutical compositions containing same - Google Patents

Description

The present invention relates to the tosylate of N-hydroxy-4-{2-[3-(N,N-dimethylaminomethyl)benzofuran-2-ylcarbonylamino]ethoxy}benzamide, or one of its solvates.

Alternatively, the subject matter of the invention relates to a toxylate salt of abexinostat of formula (I): - What?

In particular, the salt of formula (II) is intended for: - What?

The present invention also relates to the crystalline form I of N-hydroxy-4-{2-[3-(N,N-dimethylaminomethyl)benzofuran-2-ylcarbonylamino]ethoxy}benzamide tosylate, its preparation process and the pharmaceutical compositions containing it.

N-hydroxy-4-{2-[3-(N,N-dimethylaminomethyl) benzofuran-2-ylcarbonylamino] ethoxy}benzamide, also known as abexinostat, is a histone deacetylase inhibitor (HDAC) described in patent application WO2004/092115. It inhibits cell growth and induces apoptosis in in vitro cultured tumor cells, and inhibits tumor growth in vivo in xenograft models (Buggy et al. 2006 Ther Ther Mol. Cancer 1305).

From an industrial point of view, it is essential to be able to synthesize the compound with excellent purity, and in particular in a perfectly reproducible form, with interesting characteristics of dissolution, filtration, drying, ease of formulation and stability allowing its prolonged storage without special conditions of temperature, light, humidity or oxygen levels.

The patent application WO2004/092115 describes two different routes to obtain abexinostat. In both cases, 3-methyl-benzofuran-2-carboxylic acid is used as the starting product, but the functionalization of this central nucleus by the dimethylaminomethyl group at position 3 is performed at different stages of the synthesis process, in this case before or after coupling of the derivative of benzofuran-2-carboxylic acid with 4- (((2-aminoethoxy) methyl benzoate. Obtaining abexinostat hydrochloride is specifically described in application WO2004/092115. However, the use of this salt on an industrial scale is made difficult by its hygroscopic properties.

The present invention describes a process for obtaining abexinostat tosylate (4-methylbenzenesulfonate of abexinostat) in a well-defined crystalline form, perfectly reproducible, and with very good stability compatible with the industrial constraints of preparation (in particular drying) and preservation of pharmaceutical compositions.

The crystalline form I of abexinostat tosylate is characterised by an X-ray diffraction diagram on powder with the following diffraction lines (Bragg angle 2 theta, expressed in degrees ±0.2°): 6.50; 9.94; 11.35; 12.33; 14.08; 18.95; 21.08; 27.05. More specifically, the crystalline form I of abexinostat tosylate is characterised by the following diffraction lines: 6.50; 9.94; 11.35; 12.33; 14.08; 18.95; 19.61; 19.96; 21.08; 22.82; 23.61; 27.05.

Specifically, the I crystal form of abexinostat tosylate is characterised by the following X-diffraction diagram on powder, measured with a PANalytical X'Pert Pro MPD diffractometer with an X'Celerator detector, and expressed in terms of line position (Bragg angle 2 theta, expressed in ±0,2°) and inter-reticular distance d (expressed in Å): - What?

1	6,50	13,581
2	9,94	8,894
3	11,35	7,789
4	12,33	7,173
5	14,08	6,285
6	18,95	4,683
7	19,61	4,526
8	19,96	4,449
9	21,08	4,215
10	22,82	3,897
11	23,61	3,768
12	27,05	3,296

In addition, the crystalline form I of abexinostat tosylate was characterised by Raman spectroscopy.

Alternatively, the I crystal form of abexinostat tosylate can be characterised by the X-diffraction diagram on powder with the 12 significant lines presented above, as well as by a Raman spectrum with a significant peak at 1608 cm-1.

Finally, the crystalline form I of abexinostat tosylate was also characterised by solid state NMR spectroscopy. Significant peaks were observed at 121.2 ppm, 122.1 ppm, 123.5 ppm, 126.0 ppm, 126.8 ppm, 128.2 ppm, 128.9 ppm, 143.4 ppm, 144.6 ppm, 153.8 ppm, 159 ppm, 161.2 ppm and 162.1 ppm. Specifically, the 13C CP/MAS (Cross Polarization Magic Angle Spinning) spectra have the following peaks (expressed in ppm ± 0,2 ppm): - What?

1	162,1	10	126,0
2	161,2	11	123,5
3	159,0	12	122,1
4	153,8	13	121,3
5	144,6	14	65,9
6	143,4	15	50,6
7	128,9	16	46,9
8	128,2	17	45,0
9	126,8	18	21,9

Err1:Expecting ',' delimiter: line 1 column 446 (char 445)

The preferred alcohols are ethanol and isopropanol, and the preferred solvents are acetone and methylethyl ketone for ketones and ethyl acetate for esters.

Alternatively, the polar medium is a binary mixture of which one of the constituents is water. More preferably still, the polar medium is a binary mixture chosen from acetone/water, ethanol/water, isopropanol/water and methylethyl ketone/water.

In the crystallization process of the invention, abexinostat (free base) obtained by any process may be used.

The invention also extends to another method of preparation of the crystalline form I of abexinostat tosylate, in which crystallization is initiated by a very small amount of the crystalline form 1 of abexinostat tosylate. In this second crystallization process according to the invention, the abexinostat (free base) obtained by any process can also be used.

The advantage of obtaining the crystalline form 1 of abexinostat tosylate is that it allows the preparation of pharmaceutical formulations with a consistent and reproducible composition, with good dissolution and stability characteristics, which is particularly advantageous when the formulations are intended for oral administration.

The crystalline form I of abexinostat tosylate is intended for the treatment of cancer, and in particular for the treatment of carcinoma, tumour, neoplasm, lymphoma, melanoma, glioma, sarcoma or blastoma.

The present invention also covers pharmaceutical formulations containing as the active substance a toxylate salt of abexinostat, and in particular the crystalline form I of abexinostat toxylate, with one or more inert, non-toxic and suitable excipients. The pharmaceutical formulations of the invention may include in particular those suitable for oral, parenteral (intravenous or subcutaneous), nasal administration, single or compound tablets, granules, sublingual tablets, drops, tablets, suppositories, creams, ointments, dermal gels, injectable preparations, oral suspensions and chewable tablets.

Orally administered pharmaceutical formulations are preferred.

The useful dose varies with patient sex, age and weight, route of administration, nature of cancer and possible associated treatments and the useful dose ranges from 20 mg to 480 mg of N-hydroxy-4-{2-[3-(N,N-dimethylaminomethyl) benzo-furan-2-ylcarbonylamino]ethoxy}benzamide expressed as free base per day.

The following examples illustrate the invention, but do not limit it in any way.

Example 1: Process for obtaining the crystalline form I of abexinostat tosylate

1.66 kg of abexinostat (free base) is placed in 9.48 kg of isopropanol/water (50/50 mass/mass) mixture at room temperature. Para-toluenesulfonic acid monohydrate (0.83 kg) is added to 2.36 kg of water at room temperature. The medium is then heated to 75°C for 30 minutes before being cooled to 0°C. When the crystallization is complete, the suspension is filtered at 20°C. After drying, the crystalline form I of abexinostat tosylate is obtained with a yield of about 85% and a purity of over 99%. The solid has been characterized by the diffraction diagram on X-ray, the Raman spectrum and the RMN spectrum detailed in Examples 3-6 below.

Example 2: Method for obtaining the crystalline form I of abexinostat tosylate (seeding)

33.9 kg of abexinostat (free base) is placed in 170 kg of isopropanol/water mixture (45.6/54.4 mass/mass) at room temperature. A solution of para-toluenesulfonic acid monohydrate (17.06 kg) in water (24.1 kg) is added. The medium is then heated to 70-75°C, cooled and pre-heated with 1.935 kg of crystalline form I of abexinostat tosylate. The suspension is then filtered at 20°C. After drying, the crystalline form I of abexinostat tosylate is obtained with an efficiency of about 86% and a purity of more than 99%. The solid has been characterized by the X-ray, the Raman powder and the Raman RN spectrum detailed in the following Examples 3-6 .

Example 3: Crystalline form I of the abexinostat tosylate (X diffraction diagram on powder)

Data were recorded on a PANalytical X'Pert Pro MPD diffractometer with an X'Celerator detector under the following conditions: 45 kV voltage, intensity 40 mA,Theta/theta mounting,Anode: copper,Wavelength K alpha-1: 1.54060 Å,Wavelength K alpha-2: 1.54443 Å,Ratio K alpha-2/K alpha-1: 0.5Mode of measurement: continuous from 3° to 55° (Bragg angle 2 theta) with an increment of 0.017°,Measurement time by step: 35.53 s.

The X-diffraction diagram on powder of shape I of abexinostat tosylate obtained by the method in Example 1 or 2 is expressed in terms of line position (Bragg angle 2 theta, expressed in degrees ±0.2°), inter-reticular distance d (expressed in Å) and relative intensity (expressed as a percentage of the most intense line).

1	6,50	13,581	75,6
2	9,94	8,894	58,4
3	11,35	7,789	19,1
4	12,33	7,173	23,7
5	14,08	6,285	33,1
6	18,95	4,683	100
7	19,61	4,526	53,9
8	19,96	4,449	50,9
9	21,08	4,215	93,5
10	22,82	3,897	28,5
11	23,61	3,768	32,6
12	27,05	3,296	16,0

Example 4: Crystalline form I of the abexinostat tosylate (crystalline mesh)

A solution of abexinostat tosylate saturated in 2,2,2-trifluoroethanol is prepared by agitating a suspension for 24 hours at room temperature, followed by filtration. 1 mL of this saturated solution is then poured into a 1.8 mL HPLC vial to which 0.25 mL of water is added. The solution is maintained at room temperature for 75 minutes. After centrifugation, the solid is isolated for analysis.

The crystal structure was determined on the previous monocrystal by means of a Bruker Kappa CCD diffractometer equipped with a molybdenum anticathode FR590 generator ((λMoKα1 = 0.7093 Å) with an angular range of 2° to 27.5° in θ. The following parameters were established: The following is a list of the three-dimensional crystalline meshes: a = 10,467 Å, b = 14,631 Â, c = 20,159 Å, α = 73,971°, β = 79,040°, γ = 72,683° spatial group: P - number of molecules in the meshes: 4volume of the meshes: V - volume = 2813,0 Å3density: d = 1,345 g/cm3.

Example 5: Crystalline form I of the abexinostat tosylate (Raman spectrum)

The spectra were acquired with maximum power (100% of the laser capacity), spot size of 100 μm, twenty 2-second exposures, and spectral resolution of 2 cm-1. The spectral range explored ranges between 0 and 3278-1 cm.

Significant peaks were observed at the following positions: 940 cm-1, 1088 cm-1, 1132 cm-1, 1242 cm-1, 1360 cm-1, 1608 cm-1.

Example 6: Crystalline form I of the abexinostat tosylate (solid NMR spectrum)

The 13C NMR spectra were recorded at room temperature using a Bruker SB Avance spectrometer with a 4 mm CP/MAS SB VTN probe under the following conditions: Frequency: 125.76 MHz,Spectral width: 40 kHz,Speed of rotation of the sample at the magic angle: 10 kHz,Pulse sequence: CP (Cross Polarization) with SPINAL64 decoupling (decoupling power 80 kHz),Repetition time: 10 s,Acquisition time: 35 ms,Contact time: 4 msNumber of scans: 4096.

A 5 Hz line broadening function is applied to the signal collected before the Fourier transform, and the resulting spectra are referenced to a sample of adamantane (the highest frequency peak of adamantane has a chemical displacement of 38.48 ppm).

The observed peaks were summarised in the following table (expressed in ppm ± 0,2 ppm): - What?

1	162,1	10	126,0
2	161,2	11	123,5
3	159,0	12	122,1
4	153,8	13	121,3
5	144,6	14	65,9
6	143,4	15	50,6
7	128,9	16	46,9
8	128,2	17	45,0
9	126,8	18	21,9

Example 7: Pharmaceutical composition

Formulation for 1000 tablets at 100 mg of abexinostat (expressed as baseline equivalent): - What?

Tosylate d'abexinostat	143,4 g
Lactose monohydrate	213,1 g
Stéarate de Magnésium	2,5 g
Amidon de maïs	75 g
Maltodextrine	50 g
Silice colloïdale anhydre	1 g
Carboxymethyl cellulose sodique	15 g

Example 8: Hygroscopy

The hygroscopicity of abexinostat tosylate form I was assessed by Dynamic Vapor Sorption (DVS) gravimetry. A 5 to 10 mg sample of the drug substance, weighed with precision, was placed in a DVS sample tank operating at 25°C under controlled humidity. Mass variation was recorded during drying below 0 per cent (relative humidity) and during two subsequent cycles of linear increase and decrease in relative humidity in the 0-90 per cent HR range at a 10 per cent limit rate. Relative humidity was maintained at 90 per cent, with a variation of up to 0.002 per cent HR for this mass, with a time limit of 15 minutes.

An increase in weight of less than 0,5% was detected by DVS analysis after exposure of a sample to relative humidities between 0% and 90% at 25°C.

Claims (18)

1. N-hydroxy-4-{2-[3-(N,N-dimethylammomethyl)benzofuran-2-ylcarbonylamino]ethoxy}benzamide tosylate or one of its solvates.
2. Salt according to claim 1 of formula (II):
3. Crystalline form I of abexinostate tosylate according to one of claims 1 or 2, characterised in that it has an X-ray powder diffraction diagram having the following diffraction lines (Bragg's angle 2 theta, expressed in degrees ±0.2°): 6.50; 9.94; 11.35; 12.33; 14.08; 18.95; 21.08; 27.05.
4. Crystalline form I of abexinostate tosylate according to claim 3, characterised in that it has an X-ray powder diffraction diagram having the following diffraction lines (Bragg's angle 2 theta, expressed in degrees ±0.2°) : 6.50; 9.94; 11.35; 12.33; 14.08; 18.95; 19.61; 19.96; 21.08; 22.82; 23.61; 27.05.
5. Crystalline form I of abexinostate tosylate according to claim 3 or 4, characterised in that it has the following X-ray powder diffraction diagram measured on a PANalytical X'Pert Pro MPD diffractometer with an X'Celerator detector and expressed in terms of line position (Bragg's angle 2, expressed in degrees ±0.2°) and interreticular distance d (expressed in Å): 1 6.50 13.581 2 9.94 8.894 3 11.35 7.789 4 12.33 7.173 5 14.08 6.285 6 18.95 4.683 7 19.61 4.526 8 19.96 4.449 9 21.08 4.215 10 22.82 3.897 11 23.61 3.768 12 27.05 3.296
6. Crystalline form I of abexinostate tosylate according to one of claims 3 to 5, characterised in that it has a Raman spectrum having a significant peak at position 1608 cm^-1.
7. Crystalline form I of abexinostate tosylate according to one of claims 1 to 6, characterised in that it has a Raman spectrum having significant peaks at positions 940 cm^-1, 1088 cm^-1, 1132 cm^-1, 1242 cm^-1, 1360 cm^-1, 1608 cm^-1.
8. Crystalline form I of abexinostate tosylate according to one of claims 1 or 2, characterised in that it has a solid-state ¹³C CP/MAS NMR spectrum having the following peaks (expressed in ppm ± 0.2 ppm): 121.2 ppm, 122.1 ppm, 123.5 ppm 126.0 ppm, 126.8 ppm, 128.2 ppm, 128.9 ppm, 143.4 ppm, 144.6 ppm, 153.8 ppm, 159 ppm, 161.2 ppm and 162.1 ppm.
9. Crystalline form I of abexinostate tosylate according to claim 8, characterised in that it has a solid-state ¹³C CP/MAS NMR spectrum having the following peaks (expressed in ppm ± 0.2 ppm): 1 162.1 10 126.0 2 161.2 11 123.5 3 159.0 12 122.1 4 153.8 13 121.3 5 144.6 14 65.9 6 143.4 15 50.6 7 128.9 16 46.9 8 128.2 17 45.0 9 126.8 18 21.9
10. Pharmaceutical composition containing abexinostate tosylate according to one of claims 1 or 2 as active ingredient in association with one or more pharmaceutically acceptable excipients.
11. Pharmaceutical composition containing the crystalline form I of abexinostate tosylate according to one of claims 3 to 9 as active ingredient in association with one or more pharmaceutically acceptable excipients.
12. Pharmaceutical composition according to claim 10 or 11 for use in the treatment of cancer.
13. Pharmaceutical composition intended to be used according to one of claims 10 to 12, in which the cancer is a carcinoma, a tumour, a neoplasm, a lymphoma, a melanoma, a glioma, a sarcoma or a blastoma.
14. Process for preparing the crystalline form I of abexinostate tosylate according to one of claims 3 to 9, in which the abexinostate is crystallised in the presence of paratoluenesulphonic acid in a polar medium.
15. Process for preparing the crystalline form I of abexinostate tosylate according to claim 14, in which the polar medium is composed of one or more solvents selected from water, alcohols, ketones and esters.
16. Process for preparing the crystalline form I of abexinostate tosylate according to claim 15, in which the polar medium is a binary mixture, in which one of the constituents is water.
17. Process for preparing the crystalline form I of abexinostate tosylate according to claim 16, in which the polar medium is a binary mixture selected from: acetone/water, ethanol/water, isopropanol/water and methyl ethyl ketone/water.
18. Process for preparing the crystalline form I of abexinostate tosylate according to one of claims 14 to 17, in which the crystallisation is activated by a very small quantity of the crystalline form I of abexinostate tosylate.