Dihydropyridophthalazinone inhibitors of poly(ADP-ribose)polymerase (PARP)

1. A method of treating breast cancer in a subject, comprising administering to the subject a therapeutically effective amount of (8S,9R)-5-fluoro-8-(4-fluorophenyl)-9-(1-methyl-1H-1,2,4-triazol-5-yl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one, or a pharmaceutically acceptable salt or solvate thereof.

2. The method of claim 1 , wherein said administration is in combination with ionizing radiation, one or more chemotherapeutic agents, or a combination thereof.

3. The method of claim 2 , wherein the compound is used in combination with one or more chemotherapeutic agents, wherein each chemotherapeutic agent is independently methyl methanesulfonate, temozolomide, dacarbazine (DTIC), a topoisomerase-1 inhibitor, Topotecan, Irinotecan, Rubitecan, Exatecan, Lurtotecan, Gimetecan, Diflomotecan, a homocamptothecin, Doxorubicin, a platinum based antineoplastic agent, a 7-substituted non-silatecan, a 7-silyl camptothecin, paclitaxel, cetuximab, daunorubicin, methotrexate, a hormone, an antiestrogen, an antiandrogen, a gonadotropin releasing hormone analog, an interferon, alpha interferon, a tyrosine kinase inhibitor, gefitinib, imatinib, gemtuzumab, or BNP 1350.

4. The method of claim 2 , wherein the compound is used in combination with one or more chemotherapeutic agents, wherein each chemotherapeutic agent is independently irinotecan, cisplatin, carboplatin, paclitaxel, or temozolomide.

5. A method of treating breast cancer in a subject, comprising administering to the subject a therapeutically effective amount of a compound having the structure:

wherein:

Y is an aryl or heteroaryl group optionally substituted with at least one R 6 ;

Z is an aryl group optionally substituted with at least one R 6 ;

A and B are each independently selected from hydrogen, Br, Cl, F, I, OH, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, alkoxy, and alkoxyalkyl;

wherein the C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, alkoxy, and alkoxyalkyl are each optionally substituted with at least one substituent selected from OH, NO 2 , CN, Br, Cl, F, I, C 1 -C 6 alkyl, and C 3 -C 8 cycloalkyl; and

wherein B is not OH;

each R 6 is independently selected from OH, NO 2 , CN, Br, Cl, F, I, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, C 2 -C 8 heterocycloalkyl, C 2 -C 6 alkenyl, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxycarbonylalkyl, C 2 -C 6 alkynyl, aryl, arylalkyl, C 3 -C 8 cycloalkylalkyl, haloalkoxy, haloalkyl, hydroxyalkylene, oxo, heteroaryl, heteroarylalkoxy, heteroaryloxy, heteroarylthio, heteroarylalkylthio, heterocycloalkoxy, C 2 -C 8 heterocycloalkylthio, heterocyclooxy, heterocyclothio, NR A R B , (NR A R B )C 1 -C 6 alkylene, (NR A R B )carbonyl, (NR A R B )carbonylalkylene, (NR A R B )sulfonyl, and (NR A R B )sulfonylalkylene;

R 2 is selected from hydrogen, Br, Cl, I, and F;

R A and R B are each independently selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, and alkylcarbonyl; or R A and R B taken together with the atom to which they are attached form a 3-10 membered heterocycle ring optionally having one to three heteroatoms or hetero functionalities selected from the group consisting of —O—, —NH—, —N(C 1 -C 6 alkyl)-, —NCO(C 1 -C 6 alkyl)-, —NCO(C 3 -C 8 cycloalkyl)-, —N(aryl)-, —N(aryl-C 1 -C 6 alkyl-)-, —N(substituted-aryl-C 1 -C 6 alkyl-)-, —N(heteroaryl)-, —N(heteroaryl-C 1 -C 6 alkyl-)-, —N(substituted-heteroaryl-C 1 -C 6 alkyl-)-, —S—, and S(O) q —;

wherein q is 1 or 2; and

wherein the 3-10 membered heterocycle ring is optionally further substituted with one or more substituents, and the substituted-aryl and substituted-heteroaryl are aryl or heteroaryl rings each independently substituted with one or more substituents;

wherein the one or more substituents are each independently selected from alkenyl, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkyl, alkylcarbonyl, alkylcarbonyloxy, alkylthio, alkylthioalkyl, alkenyl, carboxy, cyano, formyl, haloalkoxy, haloalkyl, halogen, hydroxyl, hydroxyalkylene, mercapto, and nitro;

or a pharmaceutically acceptable salt or solvate thereof.

6. The method of claim 5 , wherein the compound is:

(8S,9R)-5-fluoro-8-(4-fluorophenyl)-9-(1-methyl-1H-1,2,4-triazol-5-yl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one;

(8S,9R)-8-(4-fluorophenyl)-9-(1-methyl-1H-imidazol-2-yl)-8,9-dihydro-2H-pyrido [4,3,2-de]phthalazin-3(7H)-one;

(8S,9R)-8-(4-fluorophenyl)-9-(1-methyl-1H-1,2,4-triazol-5-yl)-8,9-dihydro-2H-pyrido [4,3,2-de]phthalazin-3(7H)-one;

(8S,9R)-5-fluoro-8-(4-fluorophenyl)-9-(1-methyl-1H-imidazol-2-yl)-8,9-dihydro-2H-pyrido [4,3,2-de]phthalazin-3(7H)-one;

(8S,9R)-5-fluoro-9-(1-methyl-1H-imidazol-2-yl)-8-phenyl-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one;

(8S,9R)-8-(4-(azetidin-1-ylmethyl)phenyl)-9-(4-fluorophenyl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one; or

(8S,9R)-8-(4-((dimethylamino)methyl)phenyl)-5-fluoro-9-(1-methyl-1H-1,2,4-triazol-5-yl)-8,9-dihydro-2H-pyrido[4,3,2-de]phthalazin-3(7H)-one;

or a pharmaceutically acceptable salt or solvate thereof.

7. The method of claim 5 , wherein the cancer is deficient in Homologous Recombination (HR) dependent DNA double strand break (DSB) repair pathway.

8. The method of claim 7 , wherein the cancer comprises one or more cancer cells having a reduced or abrogated ability to repair DNA DSB by HR relative to normal cells.

9. The method of claim 8 , wherein the cancer cells have a BRCA1 or BRCA2 deficient phenotype.

10. The method of claim 9 , wherein the cancer cells are deficient in BRCA1 or BRCA2.

11. The method of claim 7 , wherein the cancer comprises one or more cancer cells deficient in proteins involved in DNA DSB repair by HR.

12. The method of claim 11 , wherein the one or more cancer cells are deficient in one or more of ATM, Rad51, Rad52, Rad54, Rad50, MRE11, NBS1, XRCC2, XRCC3, cABL, RPA, CtIP, and MBC.

13. The method of claim 5 , wherein the subject is heterozygous for a mutation in a gene encoding a component of the HR dependent DNA DSB repair pathway.

14. The method of claim 5 , wherein the subject is heterozygous for a mutation in BRCA1 and/or BRCA2.

15. The method of claim 5 , wherein the breast cancer is locally advanced or metastatic breast cancer or advanced ovarian cancer.

16. The method of claim 1 , wherein the cancer is deficient in Homologous Recombination (HR) dependent DNA double strand break (DSB) repair pathway.

17. The method of claim 16 , wherein the cancer comprises one or more cancer cells having a reduced or abrogated ability to repair DNA DSB by HR relative to normal cells.

18. The method of claim 17 , wherein the cancer cells have a BRCA1 or BRCA2 deficient phenotype.

19. The method of claim 18 , wherein the cancer cells are deficient in BRCA1 or BRCA2.

20. The method of claim 16 , wherein the cancer comprises one or more cancer cells deficient in proteins involved in DNA DSB repair by HR.

21. The method of claim 20 , wherein the one or more cancer cells are deficient in one or more of ATM, Rad51, Rad52, Rad54, Rad50, MRE11, NBS1, XRCC2, XRCC3, cABL, RPA, CtIP, and MBC.

22. The method of claim 1 , wherein the subject is heterozygous for a mutation in a gene encoding a component of the HR dependent DNA DSB repair pathway.

23. The method of claim 1 , wherein the subject is heterozygous for a mutation in BRCA1 and/or BRCA2.

24. The method of claim 1 , wherein the breast cancer is locally advanced or metastatic breast cancer or advanced ovarian cancer.

25. The method of claim 5 , wherein said administering is in combination with ionizing radiation, one or more chemotherapeutic agents, or a combination thereof.

26. The method of claim 25 , wherein said administering is in combination with one or more chemotherapeutic agents, wherein each chemotherapeutic agent is independently methyl methanesulfonate, temozolomide, dacarbazine (DTIC), a topoisomerase-1 inhibitor, Topotecan, Irinotecan, Rubitecan, Exatecan, Lurtotecan, Gimetecan, Diflomotecan, a homocamptothecin, Doxorubicin, a platinum based antineoplastic agent, a 7-substituted non-silatecan, a 7-silyl camptothecin, paclitaxel, cetuximab, daunorubicin, methotrexate, a hormone, an antiestrogen, an antiandrogen, a gonadotropin releasing hormone analog, an interferon, alpha interferon, a tyrosine kinase inhibitor, gefitinib, imatinib, gemtuzumab, or BNP 1350.

27. The method of claim 26 , wherein the compound is used in combination with one or more chemotherapeutic agents, wherein each chemotherapeutic agent is independently irinotecan, cisplatin, carboplatin, paclitaxel, or temozolomide.