Claims for Patent: 10,112,942

Summary for Patent: 10,112,942

Title:	Substituted pyrazolo[1,5-A]pyridine compounds as RET kinase inhibitors
Abstract:	Provided herein are compounds of the Formula I: and stereoisomers and pharmaceutically acceptable salts or solvates thereof, in which A, B, X1, X2, X3, X4, Ring D, and E have the meanings given in the specification, which are inhibitors of RET kinase and are useful in the treatment and prevention of diseases which can be treated with a RET kinase inhibitor, including RET-associated diseases and disorders.
Inventor(s):	Steven W. Andrews, Sean Aronow, James F. Blake, Barbara J. Brandhuber, Adam Cook, Julia Haas, Yutong Jiang, Gabrielle R. Kolakowski, Elizabeth A. McFaddin, Megan L. McKenney, Oren T. McNulty, Andrew T. Metcalf, David A. Moreno, Tony P. Tang, Li Ren
Assignee:	Array Biopharma Inc
Application Number:	US15/858,240
Patent Claims:	1. A compound of the Formula I: and pharmaceutically acceptable salts and solvates thereof, wherein: X1, X2, X3 and X4 are independently CH or N, wherein zero, one or two of X1, X2, X3 and X4 is N; A is CN; B is (b) C1-C6 alkyl optionally substituted with 1-3 fluoros, (c) hydroxyC2-C6 alkyl-, wherein the alkyl portion is optionally substituted with 1-3 fluoros or a C3-C6 cycloalkylidene ring, (e) (C1-C6 alkoxy)C1-C6 alkyl- optionally substituted with 1-3 fluoros, (f) (R1R2N)C1-C6 alkyl-, wherein said alkyl portion is optionally substituted with OH and wherein R1 and R2 are independently H or C1-C6 alkyl (optionally substituted with 1-3 fluoros); (g) hetAr1C1-C3 alkyl-, wherein hetAr1 is a 5-6 membered heteroaryl ring having 1-3 ring heteroatoms independently selected from N, O and S and is optionally substituted with one or more independently selected C1-C6 alkyl substituents; or (i) (hetCyca)C1-C3 alkyl-, hetCyca- is a 4-6 membered heterocyclic ring having 1-2 ring heteroatoms independently selected from N and O and optionally substituted with one or more substituents independently selected from OH, C1-C6 alkyl (optionally substituted with 1-3 fluoros), hydroxyC1-C6 alkyl-, C1-C6 alkoxy, (C1-C6 alkyl)C(═O)—, (C1-C6 alkoxy)C1-C6 alkyl- and fluoro, or wherein hetCyca is substituted with oxo; Ring D is (i) a saturated 4-7 membered heterocyclic ring having two ring nitrogen atoms, or (ii) a saturated 7-9 membered bridged heterocyclic ring having two ring nitrogen atoms and optionally having a third ring heteroatom which is oxygen, wherein each of said rings is optionally substituted with (a) one to four groups independently selected from halogen, OH, C1-C3 alkyl which is optionally substituted with 1-3 fluoros, or C1-C3 alkoxy which is optionally substituted with 1-3 fluoros, (b) a C3-C6 cycloalkylidene ring, or (c) an oxo group; E is (h) Ar1C1-C6 alkyl-, (j) hetAr2C1-C6 alkyl-, wherein the alkyl portion is optionally substituted with 1-3 fluoros, or (l) hetAr2C(═O)—, Ar1 is phenyl optionally substituted with one or more substituents independently selected from the group consisting of halogen, CN, C1-C6 alkyl (optionally substituted with 1-3 fluoros), C1-C6 alkoxy (optionally substituted with 1-3 fluoros), ReRfN— wherein Re and Rf are independently H or C1-C6 alkyl, (RpRqN)C1-C6 alkoxy- wherein RP and Rq are independently H or C1-C6 alkyl, and (hetAra)C1-C6 alkyl- wherein hetAra is a 5-6 membered heteroaryl ring having 1-2 ring nitrogen atoms, or Ar1 is a phenyl ring fused to a 5-6 membered heterocyclic ring having 1-2 ring heteroatoms independently selected from N and 0; and hetAr2 is a 5-6 membered heteroaryl ring having 1-3 ring heteroatoms independently selected from N, O and S or a 9-10 membered bicyclic heteroaryl ring having 1-3 ring nitrogen atoms, wherein hetAr2 is optionally substituted with one or more substituents independently selected from the group consisting of halogen, CN, C1-C6 alkyl (optionally substituted with 1-3 fluoros), C1-C6 alkoxy (optionally substituted with 1-3 fluoros), (C1-C6 alkoxy)C1-C6 alkyl-(optionally substituted with 1-3 fluoros), ReRfN— wherein Re and Rf are independently H or C1-C6 alkyl, OH, (C1-C6 alkoxy)C1-C6 alkoxy- and C3-C6 cycloalkyl. 2. A compound according to claim 1, wherein Ring D is wherein the wavy line indicates the point of attachment to the ring comprising X1, X2, X3 and X4, and the asterisk indicates the point of attachment to the E group, and wherein said ring is optionally substituted with (a) one to four groups independently selected from halogen, OH, C1-C3 alkyl which is optionally substituted with 1-3 fluoros, or C1-C3 alkoxy which is optionally substituted with 1-3 fluoros, (b) a C3-C6 cycloalkylidene ring, or (c) an oxo group. 3. A compound according to claim 2, wherein E is: (h) Ar1C1-C6 alkyl-, or (j) hetAr2C1-C6 alkyl- wherein said alkyl portion is optionally substituted with 1-3 fluoros. 4. A compound according to claim 1, wherein Ring D is wherein the wavy line indicates the point of attachment to the ring comprising X1, X2, X3 and X4, and the asterisk indicates the point of attachment to the E group, and wherein said ring is optionally substituted with (a) one to four groups independently selected from halogen, OH, C1-C3 alkyl which is optionally substituted with 1-3 fluoros, or C1-C3 alkoxy which is optionally substituted with 1-3 fluoros, (b) a C3-C6 cycloalkylidene ring, or (c) an oxo group. 5. A compound according to claim 4, wherein E is (j) hetAr2C1-C6 alkyl- wherein said alkyl portion is optionally substituted with 1-3 fluoros, or (l) hetAr2C(═O)—. 6. A compound according to claim 3, wherein B is (c) hydroxyC2-C6 alkyl- wherein the alkyl portion is optionally substituted with a C3-C6 cycloalkylidene ring, (e) (C1-C6 alkoxy)C1-C6 alkyl- optionally substituted with 1-3 fluoros, or (i) (hetCyca)C1-C3 alkyl-. 7. A compound according to claim 5, wherein B is (b) C1-C6 alkyl optionally substituted with 1-3 fluoros, or (c) hydroxyC2-C6 alkyl- wherein the alkyl portion is optionally substituted with a C3-C6 cycloalkylidene ring, (f) (R1R2N)C1-C6 alkyl-, wherein said alkyl portion is optionally substituted with OH and wherein R1 and R2 are independently H or C1-C6 alkyl (optionally substituted with 1-3 fluoros); (g) hetAr1C1-C3 alkyl-, wherein hetAr1 is a 5-6 membered heteroaryl ring having 1-3 ring heteroatoms independently selected from N, O and S and is optionally substituted with one or more independently selected C1-C6 alkyl substituents; or (i) (hetCyca)C1-C3 alkyl-. 8. A compound according to claim 1, wherein X1 is N, and X2, X3 and X4 are CH. 9. A compound according to claim 1, wherein the compound of Formula I is selected from the group consisting of: 4-(6-(4-benzylpiperazin-1-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile; 6-(2-hydroxyethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; (R)-6-(2-hydroxypropoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; 6-(2-methoxyethoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(6-methoxynicotinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; 6-(2-(dimethylamino)ethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; 4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile; 4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-((l-methyl-1H-imidazol-4-yl)methoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile; and 6-ethoxy-4-(5-(6-((5-fluoro-6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyrazin-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile; or a pharmaceutically acceptable salt thereof. 10. A compound according to claim 1, wherein the compound of Formula I is 4-(6-(4-benzylpiperazin-1-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 11. A compound according to claim 1, wherein the compound of Formula I is 6-(2-hydroxyethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 12. A compound according to claim 1, wherein the compound of Formula I is (R)-6-(2-hydroxypropoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 13. A compound according to claim 1, wherein the compound of Formula I is 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 14. A compound according to claim 1, wherein the compound of Formula I is 6-(2-methoxyethoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 15. A compound according to claim 1, wherein the compound of Formula I is 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(6-methoxynicotinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 16. A compound according to claim 1, wherein the compound of Formula I is 6-(2-(dimethylamino)ethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 17. A compound according to claim 1, wherein the compound of Formula I is 4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 18. A compound according to claim 1, wherein the compound of Formula I is 4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-((1-methyl-1H-imidazol-4-yl)methoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 19. A compound according to claim 1, wherein the compound of Formula I is 6-ethoxy-4-(5-(6-((5-fluoro-6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyrazin-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 20. A pharmaceutical composition, comprising a compound according to claim 1, or a pharmaceutically acceptable salt or solvate thereof, in admixture with a pharmaceutically acceptable diluent or carrier. 21. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 4-(6-(4-benzylpiperazin-1-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 22. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 6-(2-hydroxyethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 23. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is (R)-6-(2-hydroxypropoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 24. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 25. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 6-(2-methoxyethoxy)-4-(6-(4-((6-methoxypyridin-3-yl)methyl)piperazin-1-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 26. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 6-(2-hydroxy-2-methylpropoxy)-4-(6-(6-(6-methoxynicotinoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 27. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 6-(2-(dimethylamino)ethoxy)-4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 28. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-(2-morpholinoethoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 29. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 4-(6-(6-((6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyridin-3-yl)-6-((1-methyl-1H-imidazol-4-yl)methoxy)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof. 30. A pharmaceutical composition according to claim 20, wherein the compound of Formula I is 6-ethoxy-4-(5-(6-((5-fluoro-6-methoxypyridin-3-yl)methyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)pyrazin-2-yl)pyrazolo[1,5-a]pyridine-3-carbonitrile, or a pharmaceutically acceptable salt thereof.