Crystalline form of the compound (S)-3-{4-[5-(2-cyclopentyl-6-methoxy-pyridin-4-yl)-[1,2,4]oxadiazol-3-yl]-2-ethyl-6-methyl-phenox

1. A method of treating multiple sclerosis comprising administering a pharmaceutically active amount of a crystalline form of the compound (S)-3-{4-[5-(2-cyclopentyl-6-methoxy-pyridin-4-yl)-[1,2,4]oxadiazol-3-yl]-2-ethyl-6-methyl-phenoxy}-propane-1,2-diol to a subject in need thereof, wherein the crystalline form is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 5.4°, 8.5°, and 10.8°.

2. The method according to claim 1 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, and 10.8°.

3. The method according to claim 1 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, 10.8°, 12.7°, 14.4°, 17.7°, 20.4°, and 21.3°.

4. The method according to claim 1 , wherein the crystalline form of the compound has a melting point of about 79° C. as determined by differential scanning calorimetry.

5. The method according to claim 2 , wherein the crystalline form of the compound has a melting point of about 79° C. as determined by differential scanning calorimetry.

6. The method according to claim 3 , wherein the crystalline form of the compound has a melting point of about 79° C. as determined by differential scanning calorimetry.

7. A method of treating multiple sclerosis comprising administering a pharmaceutical composition to a subject in need thereof; wherein the pharmaceutical composition comprises a crystalline form of the compound (S)-3-{4-[5-(2-cyclopentyl-6-methoxy-pyridin-4-yl)-[1,2,4]oxadiazol-3-yl]-2-ethyl-6-methyl-phenoxy}-propane-1,2-diol, wherein the crystalline form is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 5.4°, 8.5°, and 10.8°; and wherein the pharmaceutical composition comprises about 2 mg or about 4 mg of the compound.

8. The method according to claim 7 , wherein the pharmaceutical composition comprises about 2 mg of the compound (S)-3-{4-[5-(2-cyclopentyl-6-methoxy-pyridin-4-yl)-[1,2,4] oxadiazol-3-yl]-2-ethyl-6-methyl-phenoxy}-propane-1,2-diol.

9. The method according to claim 7 , wherein the pharmaceutical composition comprises about 4 mg of the compound (S)-3-{4-[5-(2-cyclopentyl-6-methoxy-pyridin-4-yl)-[1,2,4] oxadiazol-3-yl]-2-ethyl-6-methyl-phenoxy}-propane-1,2-diol.

10. The method according to claim 7 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, and 10.8°.

11. The method according to claim 8 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, and 10.8°.

12. The method according to claim 9 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, and 10.8°.

13. The method according to claim 7 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, 10.8°, 12.7°, 14.4°, 17.7°, 20.4°, and 21.3°.

14. The method according to claim 8 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, 10.8°, 12.7°, 14.4°, 17.7°, 20.4°, and 21.3°.

15. The method according to claim 9 , wherein the crystalline form of the compound is characterized by the presence of peaks in the X-ray powder diffraction diagram at the following angles of refraction 2θ: 4.2°, 5.4°, 8.0°, 8.5°, 10.8°, 12.7°, 14.4°, 17.7°, 20.4°, and 21.3°.

16. The method according to claim 11 , wherein the crystalline form of the compound has a melting point of about 79° C. as determined by differential scanning calorimetry.

17. The method according to claim 12 , wherein the crystalline form of the compound has a melting point of about 79° C. as determined by differential scanning calorimetry.

18. The method according to claim 14 , wherein the crystalline form of the compound has a melting point of about 79° C. as determined by differential scanning calorimetry.

19. The method according to claim 15 , wherein the crystalline form of the compound has a melting point of about 79° C. as determined by differential scanning calorimetry.