Pyrrolidine-2, 5-dione derivatives, pharmaceutical compositions and methods for use as IDO1 inhibitors

1. A pharmaceutical composition comprising a compound of Formula I′, a compound of Formula I″, or a mixture thereof:

or a pharmaceutically acceptable enantiomer, salt, solvate or prodrug thereof, wherein:

X represents —NH— or —CQ 2 =CQ 3 -;

Q 2 and Q 3 each independently represent H or C1 to C6 alkyl;

R 1 and R 2 each independently represent H, halo, cyano, C1 to C6 alkyl or C1 to C6 alkoxy;

and at least one pharmaceutically acceptable carrier.

2. The pharmaceutical composition according to claim 1 , wherein Q 2 and Q 3 each independently represent H or methyl.

3. The pharmaceutical composition according to claim 1 , wherein Q 2 and Q 3 each are H.

4. The pharmaceutical composition according to claim 1 , wherein R 1 and R 2 each independently represent H or halo.

5. The pharmaceutical composition according to claim 1 , wherein the composition comprises a racemate which comprises approximately equal molar amounts of the compound of Formula I′ and the compound of Formula I″.

6. The pharmaceutical composition according to claim 1 , wherein the composition comprises different molar amounts of the compound of Formula I′ and the compound of Formula I″.

7. The pharmaceutical composition according to claim 6 , wherein the composition comprises a mixture of the compound of Formula I′ and the compound of Formula I″, wherein the composition comprises greater than 50% of a compound of Formula I′.

8. The pharmaceutical composition according to claim 7 , wherein the composition comprises at least 95% to 100% of the compound of Formula I′.

9. The pharmaceutical composition according to claim 1 , wherein the compound is of Formula I′ is selected from the group consisting of:

(a) (−)-(R)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(b) (−)-(R)-3-(1H-indol-3-yl)pyrrolidine-2,5-dione;

(c) (−)-(R)-3-(5-chloro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(d) (R)-3-(6-chloro-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione; and

(e) (R)-3-(6-bromo-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione,

or a pharmaceutically acceptable salt or solvate of any of (a) to (e).

10. The pharmaceutical composition according to claim 1 , which comprises a racemic mixture of a compound of Formula I′ and Formula I″, wherein the racemate is selected from the group consisting of:

(i) 3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(ii) 3-(1H-indol-3-yl)pyrrolidine-2,5-dione;

(iii) 3-(5-chloro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(iv) 3-(6-chloro-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(v) 3-(6-bromo-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(vi) 3-(5-bromo-1H-indol-3-yl)pyrrolidine-2,5-dione;

(vii) 3-(5-methyl-1H-indol-3-yl)pyrrolidine-2,5-dione;

(viii) 3-(5-methoxy-1H-indol-3-yl)pyrrolidine-2,5-dione;

(ix) 3-(2,5-dioxopyrrolidin-3-yl)-1H-indole-5-carbonitrile;

(x) 3-(5,6-difluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(xi) 3-(5-fluoro-6-methyl-1H-indol-3-yl)pyrrolidine-2,5-dione;

(xii) 3-(6-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(xiii) 3-(6-chloro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(xiv) 3-(6-bromo-1H-indol-3-yl)pyrrolidine-2,5-dione;

(xv) 3-(6-methyl-1H-indol-3-yl)pyrrolidine-2,5-dione;

(xvi) 3-(6-methoxy-1H-indol-3-yl)pyrrolidine-2,5-dione;

(xvii) 3-(2,5-dioxopyrrolidin-3-yl)-1H-indole-6-carbonitrile;

(xviii) 3-(naphthalen-1-yl)pyrrolidine-2,5-dione;

(xix) 3-(6-fluoronaphthalen-1-yl)pyrrolidine-2,5-dione;

(xx) 3-(7-fluoronaphthalen-1-yl)pyrrolidine-2,5-dione;

(xxii) 3-(6-chloronaphthalen-1-yl)pyrrolidine-2,5-dione; or

(xxiii) 3-(7-chloronaphthalen-1-yl)pyrrolidine-2,5-dione.

11. The pharmaceutical composition according to claim 1 , wherein at least one of the hydrogen atoms of the compound of Formula I′, one of the hydrogen atoms of the compound of Formula I″, or a hydrogen atom in both the compound of Formula I and the compound of Formula I″ are replaced with a deuterium atom.

12. The pharmaceutical composition according to claim 11 , wherein the compound of formula I″ is selected from the group consisting of:

(a″) (S)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(b″) (S)-3-(1H-indol-3-yl)pyrrolidine-2,5-dione;

(c″) (S)-3-(5-chloro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(d″) (S)-3-(6-chloro-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione; and

(e″) (S)-3-(6-bromo-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione,

or a pharmaceutically acceptable salt or solvate thereof.

13. The pharmaceutical composition according to claim 1 , wherein the compound is a free base.

14. The pharmaceutical composition according to claim 1 , which is a salt.

15. The pharmaceutical composition according to claim 14 , wherein the salt is selected from the group consisting of: an aluminium, calcium, choline, potassium, sodium or zinc salt.

16. The pharmaceutical composition according to claim 1 , which is a solvate.

17. The pharmaceutical composition according to claim 1 which is a prodrug.

18. A compound of Formula I′ or I″

or a pharmaceutically acceptable salt, solvate or prodrug thereof, wherein

X represents —NH—;

R 1 and R 2 each independently represent H, halo, cyano, C1 to C6 alkyl or C1 to C6 alkoxy.

19. The compound according to claim 18 , wherein R 1 and R 2 each independently represent H or halo.

20. The compound according to claim 18 , wherein at least one of the hydrogen atoms of the compound of Formula I′ or the compound of Formula I″ is replaced with a deuterium atom.

21. The compound according to claim 18 , wherein the compound of Formula I′ is selected from the group consisting of:

(a) (−)-(R)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(b) (−)-(R)-3-(1H-indol-3-yl)pyrrolidine-2,5-dione;

(c) (−)-(R)-3-(5-chloro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(d) (R)-3-(6-chloro-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione; and

(e) (R)-3-(6-bromo-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione,

or a pharmaceutically acceptable salt or solvate of any of (a) to (e).

22. The compound according to claim 18 , wherein the compound of Formula I″ is selected from the group consisting of:

(a″) (S)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(b″) (S)-3-(1H-indol-3-yl)pyrrolidine-2,5-dione;

(c″) (S)-3-(5-chloro-1H-indol-3-yl)pyrrolidine-2,5-dione;

(d″) (S)-3-(6-chloro-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione; and

(e″) (S)-3-(6-bromo-5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione,

or a pharmaceutically acceptable salt or solvate of any of (a) to (e).

23. The compound according to claim 18 , which is a free base.

24. The compound according to claim 18 , which is a salt.

25. A compound having the structure of Formula II′:

or a pharmaceutically acceptable salt or solvate thereof.

26. The compound according to claim 25 , wherein the compound is a free base.

27. A compound having the structure of Formula II″:

or a pharmaceutically acceptable salt thereof.

28. The compound according to claim 27 , wherein the compound is a free base.

29. A pharmaceutical composition comprising a compound according to claim 27 and a pharmaceutically acceptable carrier.

30. A pharmaceutical composition comprising a compound according to claim 27 and a pharmaceutically acceptable carrier.

31. A pharmaceutical composition comprising a mixture of compounds of Formula II′ and Formula II″

or a pharmaceutically acceptable salt thereof.

32. The pharmaceutical composition according to claim 31 , wherein the compound of Formula II′ and the compound of Formula II″ are present in a molar ration of about at a ratio of about 1:1.

33. The pharmaceutical composition according to claim 31 , wherein the compound of Formula II′ is present in an amount of at least about 75 mol %.

34. The pharmaceutical composition according to claim 31 , wherein the compound of Formula II′ is present in amount of at least about 90 mol %.

35. A pharmaceutical composition comprising a compound of the structure:

or a pharmaceutically acceptable salt or solvate thereof, or a deuterated form thereof, and a pharmaceutically acceptable carrier.

36. The composition according to claim 35 , wherein the compound of Formula II is in free base form.

37. The pharmaceutical composition according to claim 4 , wherein the halo is F.

38. The pharmaceutical composition according to claim 9 , wherein the compound is (−)-(R)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione or a pharmaceutically acceptable salt thereof.

39. The pharmaceutical composition according to claim 10 , wherein the racemate is 3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione or a pharmaceutically acceptable salt thereof.

40. The pharmaceutical composition according to claim 12 , wherein the compound is (S)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione or a pharmaceutically acceptable salt thereof.

41. The compound according to claim 19 , wherein the halo is F.

42. The compound according to claim 21 , wherein the compound is (−)-(R)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione or a pharmaceutically acceptable salt thereof.

43. The compound according to claim 22 , wherein the compound is (S)-3-(5-fluoro-1H-indol-3-yl)pyrrolidine-2,5-dione or a pharmaceutically acceptable salt thereof.

44. A pharmaceutical composition comprising a compound of Formula I′, a pharmaceutically acceptable salt of Formula I′, a compound of Formula I″, a pharmaceutically acceptable salt of Formula I″, or mixture thereof:

wherein:

X represents —NH;

R 1 and R 2 each independently represent H, halogen, cyano, C1 to C6 alkyl or C1 to C6 alkoxy;

and at least one pharmaceutically acceptable carrier, diluent, excipient and/or adjuvant.

45. The pharmaceutical composition according to claim 44 , wherein the compound is Formula I′ or a pharmaceutically acceptable salt thereof.

46. The pharmaceutical composition according to claim 45 , wherein the compound is a salt.

47. The pharmaceutical composition according to claim 45 , wherein the compound is a free base.

48. The pharmaceutical composition according to claim 44 , wherein the compound is of Formula I″ or a pharmaceutically acceptable salt thereof.

49. The pharmaceutical composition according to claim 41 , wherein the compound is a salt.

50. The pharmaceutical composition according to claim 41 , wherein the compound is a free base.

51. The pharmaceutical composition according to claim 41 , wherein R 1 is a halo.

52. The pharmaceutical composition according to claim 51 , wherein the halo is a F.

53. The pharmaceutical composition according to claim 44 , wherein R 2 is H.

54. The pharmaceutical composition according to claim 44 , wherein the composition comprises approximately equal molar amounts of the compound of Formula I′ or salt thereof and the compound of Formula I″ or salt thereof.

55. The pharmaceutical composition according to claim 44 , wherein the composition comprises different molar amounts of the compound of Formula I′ or salt thereof and the compound of Formula I″ or salt thereof.