2-indolyl imidazo [4,5-d] phenanthroline derivatives and their use in the treatment of cancer

1. A compound of Formula (I):

or a salt thereof, wherein:

R1, R3, R4, R5, and R7 are hydrogen;

R2 is halogen; and

R6 is C1-C4 alkyl.

2. The compound according to claim 1 , wherein:

R6 is CH 3 , isopropyl, or t-butyl.

3. The compound according to claim 1 , wherein:

R6 is CH 3 .

4. The compound according to claim 1 , wherein:

R2 is F or Br.

5. The compound according to claim 1 , wherein:

R2 is F.

6. The compound according to claim 1 , wherein said compound is selected from the group consisting of:

or a salt thereof.

7. The compound according to claim 1 , wherein said compound is:

or a salt thereof.

8. A pharmaceutical composition comprising the compound according to claim 1 , or a salt thereof, and a pharmaceutically acceptable carrier.

9. The pharmaceutical composition according to claim 8 , wherein in the compound of Formula I: R6 is CH 3 , isopropyl, or t-butyl.

10. The pharmaceutical composition according to claim 8 , wherein in the compound of Formula I: R6 is CH 3 .

11. The pharmaceutical composition according to claim 8 , wherein in the compound of Formula I: R2 is F or Br.

12. The pharmaceutical composition according to claim 8 , wherein in the compound of Formula I: R2 is F.

13. The pharmaceutical composition according to claim 8 , wherein the compound is selected from the group consisting of:

or a salt thereof.

14. The pharmaceutical composition according to claim 8 , wherein the compound is:

or a salt thereof.

15. A method of treating cancer in a mammal, comprising administering to said mammal an effective amount of a compound according to claim 1 , or a salt thereof, wherein said cancer is non-small cell lung cancer, colon cancer, breast cancer, ovarian cancer, leukemia, renal cancer, melanoma, prostate cancer or CNS cancer.

16. The method according to claim 15 , wherein in the compound of Formula I: R6 is CH 3 , isopropyl, or t-butyl.

17. The method according to claim 15 , wherein in the compound of Formula I: R6 is CH 3 .

18. The method according to claim 15 , wherein in the compound of Formula I: R2 is F or Br.

19. The method according to claim 15 , wherein in the compound of Formula I: R2 is F.

20. The method according to claim 15 , wherein the compound is selected from the group consisting of:

or a salt thereof.

21. The method according to claim 15 , wherein the compound is:

or a salt thereof.

22. The method according to claim 15 , wherein said cancer is a solid tumour.

23. The method according to claim 22 , wherein said solid tumour is selected from the group of: non-small cell lung tumour, colon tumour, prostate tumour, breast tumour, and melanoma tumour.

24. The method according to claim 15 , wherein said cancer is a leukaemia.

25. The compound according to claim 1 , wherein said salt is an HCl salt.

26. The pharmaceutical composition according to claim 8 , wherein said composition is a liposomal or lipid micelle formulation.

27. The pharmaceutical composition according to claim 8 , wherein said salt is an HCl salt.

28. The pharmaceutical composition according to claim 8 , wherein said composition is formulated for intravenous administration.

29. The method according to claim 15 , wherein said compound is administered as a liposomal or lipid micelle formulation.

30. The method according to claim 15 , wherein said salt is an HCl salt.

31. The method according to claim 15 , wherein said compound is administered to said mammal intravenously.

32. The method according to claim 15 , wherein said CNS cancer is a glioma.

33. The method according to claim 15 , wherein said cancer is non-small cell lung cancer.

34. The method according to claim 15 , wherein said cancer is colon cancer.

35. The method according to claim 21 , wherein said cancer is non-small cell lung cancer.

36. The method according to claim 21 , wherein said cancer is colon cancer.