Inhibitors of Tryptophan Dioxygenases (IDO1 and TDO) And Their Use In Therapy

Abstract

Pharmaceutical compositions comprising 3-aminoisoxazolopyridine compounds of the Formula I having IDO1 and/or TDO inhibitory activity are described, where W is CR1, N or N-oxide; X is CR2, N or N-oxide; Y is CR3, N or N-oxide; Z is CR4, N or N-oxide; and at least one of W, X, Y, and Z is N or N-oxide; and R9 and R10 are as defined. Also described are methods of using such compounds in the treatment of various conditions, such as cancer.

1 . A pharmaceutical composition comprising:
 a compound of Formula I or a pharmaceutically acceptable salt thereof, wherein:   
       
         
           
           
               
               
           
         
         W is CR 1 , N or N-oxide; 
         X is CR 2 , N or N-oxide; 
         Y is CR 3 , N or N-oxide; 
         Z is CR 4 , N or N-oxide; 
         and where at least one of W, X, Y, and Z is N or N-oxide; 
         R 1 , R 2 , R 3  and R 4  are each independently selected from the following groups: H, halo, R, —OH, —OR, —OC(O)H, —OC(O)R, —OC(O)NH 2 , —OC(O)NHR, —OC(O)NRR, —OP(O)(OH) 2 , —OP(O)(OR) 2 , —NO 2 , —NH 2 , —NHR, —NRR, —NHC(O)H, —NHC(O)R, —NRC(O)R, —NHC(O)NH 2 , —NHC(O)NRR, —NRC(O)NHR, —SH, —SR, —S(O)H, —S(O)R, —SO 2 R, —SO 2 NH 2 , —SO 2 NHR, —SO 2 NRR, —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —CN, —C≡CH, —C≡CR, —CH═CHR, —CH═CRR, —CR═CHR, —CR═CRR, —CO 2 H, —CO 2 R, —CHO, —C(O)R, —C(O)NH 2 , —C(O)NHR, —C(O)NRR, —CONHSO 2 H, —CONHSO 2 R, —CONRSO 2 R, cyclic C 3 -C 7  alkylamino, imidazolyl, C 1 -C 6  alkylpiperazinyl, morpholinyl and thiomorpholinyl; 
         or R 1  and R 2  taken together, or R 2  and R 3  taken together, or R 3  and R 4  taken together can form a saturated or a partially saturated or a fully unsaturated 5- or 6-membered ring of carbon atoms optionally including 1 to 3 heteroatoms selected from O, N and S, and the ring is optionally substituted independently with 1 to 4 substituents selected from R; 
         each R is independently selected from any of the groups defined in paragraphs (a) and (b) below: 
         (a) an optionally substituted C 1-6  alkyl group, an optionally substituted C 2-6  alkenyl group, an optionally substituted C 2-6  alkynyl group and an optionally substituted C 3-7  cyclic alkyl group; wherein the one or more optional substituents for each of said alkyl, alkenyl, alkynyl and cyclic alkyl groups are each independently selected from the following groups: halo, —OH, —OR 5 , —OC(O)R 5 , —OC(O)NH 2 , —OC(O)NHR 5 , —OC(O)NR 5 R 5 , —OP(O)(OH) 2 , —OP(O)(OR 5 ) 2 , —NO 2 , —NH 2 , —NHR 5 , —NR 5 R 5 , —N + (O − )R 5 R 5 , —NHC(O)H, —NHC(O)R 5 , —NR 5 C(O)R 5 , —NHC(O)NH 2 , —NHC(O)NR 5 R 5 , —NR 5 C(O)NHR 5 , —SH, —SR 5 , —S(O)H, —S(O)R 5 , —SO 2 R 5 , —SO 2 NH 2 , —SO 2 NHR 5 , —SO 2 NR 5 R 5 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —CN, —CO 2 H, —CO 2 R 5 , —CHO, —C(O)R 5 , —C(O)NH 2 , —C(O)NHR 5 , —C(O)NR 5 R 5 , —CONHSO 2 H, —C(O)NHSO 2 R 5 , —C(O)NR 5 SO 2 R 5 , cyclic C 3 -C 7  alkylamino, imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl and azetidinyl; wherein each of the groups imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl and azetidinyl are optionally substituted by one or more of the following groups: C 1-6  alkyl, C 2-6  alkenyl, C 2-6  alkynyl, C 3-7  cyclic alkyl, halo, —OH, —OR 7 , —OC(O)R 7 , —OC(O)NH 2 —OC(O)NHR 7 , —OC(O)NR 7 R 7 , —OP(O)(OH) 2 , —OP(O)(OR 7 ) 2 , —NO 2 , —NH 2 , —NHR 7 , —NR 7 R 7 , 
         —N + (O − ) R 7 R 7 , —NHC(O)H, —NHC(O)R 7 , —NR 7 C(O)R 7 , —NHC(O)NH 2 , —NHC(O)NR 7 R 7 , —NR 7 C(O)NHR 7 , —SH, —SR 7 , —S(O)H, —S(O)R 7 , —SO 2 R 7 , —SO 2 NH 2 , —SO 2 NHR 7 , —SO 2 NR 7 R 7 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 7 , —CHO, —C(O)R 7 , —C(O)NH 2 , —C(O)NHR 7 , —C(O)NR 7 R 7 , —CONHSO 2 H, —C(O)NHSO 2 R 7 , —C(O)NR 7 SO 2 R 7 , an optionally substituted aryl, and an optionally substituted heteroaryl group having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; and wherein the one or more optional substituents for each of said aryl and heteroaryl groups are each independently selected from the following groups: C 1-6  alkyl, C 2-6  alkenyl, C 2-8  alkynyl or C 3-7  cyclic alkyl, halo, —OH, —OR 8 , —OC(O)R 8 , —OC(O)NH 2 , —OC(O)NHR 8 , —OC(O)NR 8 R 8 , —OP(O)(OH) 2 , —OP(O)(OR 8 ) 2 , —NO 2 , —NH 2 , —NHR 8 , —NR 8 R 8 , —N + (O)R 8 R 8 , —NHC(O)H, —NHC(O)R 8 , —NR 8 C(O)R 8 , —NHC(O)NH 2 , —NHC(O)NR 8 R 8 , —NR 8 C(O)NHR 8 , —SH, —SR 8 , —S(O)H, —S(O)R 8 , —SO 2 R 8 , —SO 2 NH 2 , —SO 2 NHR 8 , —SO 2 NR 8 R 8 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 8 , —CHO, —C(O)R 8 , —C(O)NH 2 , —C(O)NHR 8 , —C(O)NR 8 R 8 , —CONHSO 2 H, —C(O)NHSO 2 R 8 , and —C(O)NR 8 SO 2 R 8 ; wherein each R 5 , R 7  and R 8  is independently selected from a C 1-6  alkyl group, a C 2-6  alkenyl group, a C 2-6  alkynyl group and a C 3-7  cyclic alkyl group; and 
         (b) an optionally substituted aryl, and an optionally substituted heteroaryl group having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; and wherein the one or more optional substituents are each independently selected from the same optional substituents as those defined in (a) above for R; 
         R 9  and R 10  are each independently selected from any of the groups defined in paragraphs (a) to (d) below, with the proviso that at least one of R 9  and R 10  is selected from any of the groups defined in paragraphs (c) and (d) below: 
         (a) H, an optionally substituted C 1-6  alkyl group, an optionally substituted C 2-6  alkenyl group, an optionally substituted C 2-6  alkynyl group, and an optionally substituted C 3-7  cyclic alkyl group; wherein the one or more optional substituents for each of said alkyl, alkenyl, alkynyl and cyclic alkyl are each independently selected from the following groups: halo, —OH, —OR 11 , —OC(O)R 11 , —OC(O)NH 2 , —OC(O)NHR 11 , —OC(O)NR 11 R 11 , —OP(O)(OH) 2 , —OP(O)(OR 11 ) 2 , —NO 2 , —NH 2 , —NHR 11 , —NR 11 R 11 , —N + (O)R 11 R 11 , —NHC(O)H, —NHC(O)R 11 , —NR 11 C(O)R 11 , —NHC(O)NH 2 , —NHC(O)NR 11 R 11 , —NR 11 C(O)NHR 11 , —SH, —SR 11 , —S(O)H, —S(O)R 11 , —SO 2 R 11 , —SO 2 NH 2 , —SO 2 NHR 11 , —SO 2 NR 11 R 11 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 11 , —CHO, —C(O)R 11 , —C(O)NH 2 , —C(O)NHR 11 , —C(O)NR 11 R 11 , —CONHSO 2 H, —C(O)NHSO 2 R 11 , —C(O)NR 11 SO 2 R 11 , cyclic C 3 -C 7  alkylamino, imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl, azetidinyl, aryl, and heteroaryl having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; wherein each of the groups cyclic C 3 -C 7  alkylamino, imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl azetidinyl, aryl and heteroaryl are optionally substituted by one or more of the following groups: C 1-6  alkyl, C 2-6  alkenyl, C 2-6  alkynyl, C 3-7  cyclic alkyl, halo, —OH, —OR 13 , —OC(O)R 13 , —OC(O)NH 2 , —OC(O)NHR 13 , —OC(O)NR 13 R 13 , —OP(O)(OH) 2 , —OP(O)(OR 13 ) 2 , —NO 2 , —NH 2 , —NHR 13 , —NR 13 R 13 , —N + (O)R 13 R 13 , —NHC(O)H, —NHC(O)R 13 , —NR 13 C(O)R 13 , —NHC(O)NH 2 , —NHC(O)NR 13 R 13 , —NR 13 C(O)NHR 13 , —SH, —SR 13 , —S(O)H, —S(O)R 13 , —SO 2 R 13 , —SO 2 NH 2 , —SO 2 NHR 13 , —SO 2 NR 13 R 13 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 13 , —CHO, —C(O)R 13 , —C(O)NH 2 , —C(O)NHR 13 , —C(O)NR 13 R 13 , —CONHSO 2 H, —C(O)NHSO 2 R 13 , and —C(O)NR 13 SO 2 R 13 ; wherein each R 11  and R 13  is independently selected from a C 1-6  alkyl group, a C 2-6  alkenyl group, a C 2-6  alkynyl group and a C 3-7  cyclic alkyl group; 
         (b) an optionally substituted aryl, and an optionally substituted heteroaryl group having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; and wherein the one or more optional substituents for each of said aryl and heteroaryl are each independently selected from the same optional substituents as those defined in (a) above for R 9  and R 10 ; 
         (c) —C(O)R 14 , —C(O)OR 14 , —C(O)NR 15 R 16 , —C(O)SR 14 , —C(S)R 14 , —C(S)OR 14  C(S)NR 15 R 16 , and —C(S)SR 14 , wherein each R 14  R 15  and R 16  is independently selected from the group consisting of H, optionally substituted C 1-6  alkyl, optionally substituted C 2-6  alkenyl, optionally substituted C 2-6  alkynyl, optionally substituted C 3-7  cyclic alkyl, optionally substituted aryl, and optionally substituted heteroaryl having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S, and wherein the one or more optional substituents for each of said alkyl, alkenyl, alkynyl, cyclic alkyl, aryl and heteroaryl for R 14 , R 15  and R 16  are each independently selected from the same optional substituents as those defined in (a) above for R 9  and R 10 ; and 
         (d) —SO 2 (CRR) n R 17 , wherein n is an integer of from 0 to 6, each R is independently selected from the groups defined above for R, and R 17  is optionally substituted aryl or optionally substituted heteroaryl having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S, and wherein the one or more optional substituents for each of said aryl and heteroaryl are independently selected from the same optional substituents as those defined in (a) above for R 9  and R 10 ; and —SO 2 R 18 , wherein R 18  is optionally substituted C 1-6  alkyl or optionally substituted C 3-7  cyclic alkyl, wherein the one or more optional substituents for each of said alkyl and cyclic alkyl are each independently selected from those defined in (a) above for R 9  and R 10 ; 
         and a pharmaceutically acceptable carrier. 
       
     
     
         2 . A pharmaceutical composition according to  claim 1 , wherein
 (a) Z is N or N-oxide, such as N, W is CR 1 , X is CR 2  and Y is CR 3 ; or   (b) X is N or N-oxide, such as N, W is CR 1 , Y is CR 3  and Z is CR 4 ; or   (c) X and Z are both N or N-oxide, such as N, W is CR 1  and Y is CR 3 .   
     
     
         3 - 4 . (canceled) 
     
     
         5 . A pharmaceutical composition according to  claim 1 , wherein R 1 , R 2 , R 3  and R 4 , where present, are each independently selected from the group consisting of H, halo, optionally substituted C 1 -C 6  alkyl, —O—R wherein R is selected from optionally substituted C 1 -C 6  alkyl and optionally substituted aryl (such as phenyl), —NHR wherein R is optionally substituted aryl, an optionally substituted aryl, and an optionally substituted heteroaryl group having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S. 
     
     
         6 . A pharmaceutical composition according to  claim 5 , wherein
 (a) R 1 , R 2 , R 3  and R 4 , where present, are each independently selected from the group consisting of H, halogen, —CF 3 , —CHF 2 , —OCF 3 , —OCHF 2 , C 1-6  alkyl, such as methyl, substituted aryl, substituted heteroaryl, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl; or   (b) one or two of R 1 , R 2 , R 3  and R 4 , where present, is H, and the others of R 1 , R 2 , R 3  and R 4  that are not H are independently selected from the group consisting of halogen, —CF 3 , —CHF 2 , —OCF 3 , —OCHF 2 , C 1-6  alkyl, such as methyl, substituted aryl, substituted heteroaryl, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl.   
     
     
         7 . (canceled) 
     
     
         8 . A pharmaceutical composition according to  claim 5 , wherein R 3  is present and selected from the group consisting of halogen, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl. 
     
     
         9 . A pharmaceutical composition according to  claim 2 , wherein:
 (a) Z is N or N-oxide, such as N, W is CR 1 , X is CR 2  and Y is CR 3 , and R 3  is selected from the group consisting of halogen, —O—R wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl; or   (b) Z is N or N-oxide, such as N, W is CR 1 , X is CR 2  and Y is CR 3 , R 1  is H, and one or both of R 2  and R 3  are other than H, for example, both R 2  and R 3  are other than H, or R 2  is H and R 3  is other than H, or R 3  is H and R 2  is other than H.   
     
     
         10 . (canceled) 
     
     
         11 . A pharmaceutical composition according to  claim 9 , wherein
 Z is N or N-oxide, such as N, W is CR 1 , X is CR 2  and Y is CR 3 , R 1  is H, and one or both of R 2  and R 3  are other than H, for example, both R 2  and R 3  are other than H, or R 2  is H and R 3  is other than H, or R 3  is H and R 2  is other than H; and   each of R 2  and R 3  that is other than H is independently selected from the group consisting of halogen, optionally substituted C 1 -C 6  alkyl, —OR wherein R is selected from optionally substituted C 1 -C 6  alkyl and optionally substituted aryl, —NHR wherein R is optionally substituted aryl; an optionally substituted aryl, such as substituted phenyl, and an optionally substituted heteroaryl group.   
     
     
         12 . A pharmaceutical composition according to  claim 11 , wherein each of R 2  and R 3  that is other than H is independently selected from the group consisting of halogen, —CF 3 , —CHF 2 , —OCF 3 , —OCHF 2 , C 1-6  alkyl such as methyl, substituted aryl, substituted heteroaryl, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl. 
     
     
         13 . (canceled) 
     
     
         14 . A pharmaceutical composition according to  claim 1 , wherein one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is selected from any of the groups defined in paragraphs (c) and (d); or
 (b) one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is selected from any of the groups defined in paragraph (c); or   (c) one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is selected from the group consisting of —C(O)R 14 , —C(O)OR 14 , —C(S)R 14 , and —C(S)OR 14 ; wherein each R 14  is independently selected from the group consisting of: (a) optionally substituted C 1-6  alkyl, for example C 1-6  alkyl wherein said alkyl is substituted by aryl and optionally one or two further substituents, and wherein said aryl is itself optionally substituted, and (b) optionally substituted aryl.   
     
     
         15 - 16 . (canceled) 
     
     
         17 . A pharmaceutical composition according to  claim 14 ,
 wherein one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is selected from the group consisting of —C(O)R 14 , —C(O)OR 14 , —C(S)R 14 , and —C(S)OR 14 ; wherein each R 14  is independently selected from the group consisting of: (a) optionally substituted C 1-6  alkyl, for example C 1-6  alkyl wherein said alkyl is substituted by aryl and optionally one or two further substituents, and wherein said aryl is itself optionally substituted, and (b) optionally substituted aryl;   where each R 14  is optionally substituted alkyl having the formula —(CH 2 ) n (aryl), wherein n is an integer from 0 to 3, such as 0 or 1, and said aryl is optionally substituted.   
     
     
         18 . A pharmaceutical composition according to  claim 14 , wherein:
 one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is selected from any of the groups defined in paragraph (c), or   one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is selected from the group consisting of —C(O)R 14 , —C(O)OR 14 , —C(S)R 14 , and —C(S)OR 14 ; wherein each R 14  is independently selected from the group consisting of: (a) optionally substituted C 1-6  alkyl, for example C 1-6  alkyl wherein said alkyl is substituted by aryl and optionally one or two further substituents, and wherein said aryl is itself optionally substituted, and (b) optionally substituted aryl; and   one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is —C(O)OR 14 .   
     
     
         19 . A pharmaceutical composition according to  claim 1 , wherein one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is selected from the group consisting of —C(O)NR 15 R 16  and —C(S)NR 15 R 16 , wherein each R 15  and R 16  is independently selected from the group consisting of (a) H, (b) optionally substituted C 1-6  alkyl, for example C 1-6  alkyl wherein said alkyl is substituted by aryl and, optionally, one or two further substituents, and wherein said aryl is itself optionally substituted, and (c) optionally substituted aryl. 
     
     
         20 . A pharmaceutical composition according to  claim 19 , wherein each R 15  and R 16  is independently selected from the group consisting of (a) H and (b) optionally substituted alkyl having the formula —(CH 2 ) n (aryl), wherein n is an integer from 0 to 3, such as 0 or 1, and said aryl is optionally substituted. 
     
     
         21 . A pharmaceutical composition according to  claim 19 , wherein one but not both of R 15  and R 16  is H. 
     
     
         22 . A pharmaceutical composition according to  claim 2 , wherein Z is N or N-oxide, such as N, W is CR 1 , X is CR 2  and Y is CR 3 , one of R 9  and R 10  is selected from the group consisting of H and optionally substituted C 1-6  alkyl (such as C 1-3  alkyl), and the other of R 9  and R 10  is —C(O)OR 14 , wherein each R 14  is independently selected from the group consisting of: (a) optionally substituted C 1-6  alkyl, for example C 1-6  alkyl wherein said alkyl is substituted by aryl and, optionally, one or two further substituents, and wherein said aryl is itself optionally substituted, and (b) optionally substituted aryl. 
     
     
         23 . A pharmaceutical composition according to  claim 22 , wherein R 14  is optionally substituted alkyl having the formula —(CH 2 ) n (aryl), wherein n is an integer from 0 to 3, such as 0 or 1, and said aryl is optionally substituted. 
     
     
         24 . A pharmaceutical composition according to  claim 22 , wherein
 (a) R 1 , R 2  and R 3  are each independently selected from the group consisting of H, halogen, —CF 3 , —CHF 2 , —OCF 3 , —OCHF 2 , C 1-6  alkyl, such as methyl, substituted aryl, substituted heteroaryl, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl; or   (b) R 1 , R 2  and R 3  are each independently selected from the group consisting of H, halogen, C 1-6  alkyl, such as methyl, substituted aryl, and substituted heteroaryl; or   (c) one or two of R 1 , R 2  and R 3  is H, and the others of R 1 , R 2  and R 3  that are not H are independently selected from the group consisting of halogen, —CF 3 , —CHF 2 , —OCF 3 , —OCHF 2 , C 1-6  alkyl, such as methyl, substituted aryl, substituted heteroaryl, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl; or   (d) R 1  is H, and one of both of R 2  and R 3  is other than H, wherein each of R 2  and R 3  that is not H is independently selected from the group consisting of halogen, —CF 3 , —CHF 2 , —OCF 3 , —OCHF 2 , C 1-6  alkyl, such as methyl, substituted aryl, substituted heteroaryl, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl.   
     
     
         25 - 27 . (canceled) 
     
     
         28 . A pharmaceutical composition according to  claim 22 , wherein R 3  is selected from the group consisting of halogen, —OR wherein R is optionally substituted aryl, and —NHR wherein R is optionally substituted aryl. 
     
     
         29 . (canceled) 
     
     
         30 . A pharmaceutical composition according to  claim 1 , wherein the compound of formula 1 is selected from the group consisting of:
 1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(4-(trifluoromethoxy)phenyl)urea (2)   1-(5-chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(4-cyanophenyl)urea (3)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(2-chlorophenyl)urea (6)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(3-chlorophenyl)urea (7)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(4-chlorophenyl)urea (8)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(2-(trifluoromethoxy)phenyl)urea (9)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(3-(trifluoromethoxy)phenyl)urea (10)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(2-methoxyphenyl)urea (11)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(3-methoxyphenyl)urea (12)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(4-methoxyphenyl)urea (13)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(2-(trifluoromethyl)phenyl)urea (14)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(4-(trifluoromethyl)phenyl)urea (16)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-phenylurea (17)   N-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-2-phenylacetamide (18)   N-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-2-(4-(trifluoromethoxy)phenyl)acetamide (19)   Phenyl (5-chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)carbamate (4)   1-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)-3-(3-(trifluoromethyl)phenyl)urea (15)   4-Fluorophenyl (5-chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)carbamate (5)   N-(5-Chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)acetamide (20)
 and pharmaceutically acceptable salts thereof. 
   
     
     
         31 - 33 . (canceled) 
     
     
         34 . A compound of Formula I or a pharmaceutically acceptable salt thereof, wherein: 
       
         
           
           
               
               
           
         
         W is CR 1 , N or N-oxide; 
         X is CR 2 , N or N-oxide; 
         Y is CR 3 , N or N-oxide; 
         Z is CR 4 , N or N-oxide; 
         and where at least one of W, X, Y, and Z is N or N-oxide; 
         R 1 , R 2 , R 3  and R 4  are each independently selected from the following groups: H, halo, R, —OH, —OR, —OC(O)H, —OC(O)R, —OC(O)NH 2 , —OC(O)NHR, —OC(O)NRR, —OP(O)(OH) 2 , —OP(O)(OR) 2 , —NO 2 , —NH 2 , —NHR, —NRR, —NHC(O)H, —NHC(O)R, —NRC(O)R, —NHC(O)NH 2 , —NHC(O)NRR, —NRC(O)NHR, —SH, —SR, —S(O)H, —S(O)R, —SO 2 R, —SO 2 NH 2 , —SO 2 NHR, —SO 2 NRR, —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —CN, —C═CH, —C═CR, —CH═CHR, —CH═CRR, —CR═CHR, —CR═CRR, —CO 2 H, —CO 2 R, —CHO, —C(O)R, —C(O)NH 2 , —C(O)NHR, —C(O)NRR, —CONHSO 2 H, —CONHSO 2 R, —CONRSO 2 R, cyclic C 3 -C 7  alkylamino, imidazolyl, C 1 -C 6 -alkylpiperazinyl, morpholinyl and thiomorpholinyl; 
         or R 1  and R 2  taken together, or R 2  and R 3  taken together, or R 3  and R 4  taken together can form a saturated or a partially saturated or a fully unsaturated 5- or 6-membered ring of carbon atoms optionally including 1 to 3 heteroatoms selected from O, N and S, and the ring is optionally substituted independently with 1 to 4 substituents selected from R; 
         each R is independently selected from any of the groups defined in paragraphs (a) and (b) below: 
         (a) an optionally substituted C 1-6  alkyl group, an optionally substituted C 2-6  alkenyl group, an optionally substituted C 2-6  alkynyl group and an optionally substituted C 3-7  cyclic alkyl group; wherein the one or more optional substituents for each of said alkyl, alkenyl, alkynyl and cyclic alkyl groups are each independently selected from the following groups: halo, —OH, —OR 5 , —OC(O)R 5 , —OC(O)NH 2 , —OC(O)NHR 5 , —OC(O)NR 5 R 5 , —OP(O)(OH) 2 , —OP(O)(OR 5 ) 2 , —NO 2 , —NH 2 , —NHR 5 , —NR 5 R 5 , —N + (O − )R 5 R 5 , —NHC(O)H, —NHC(O)R 5 , —NR 5 C(O)R 5 , —NHC(O)NH 2 , —NHC(O)NR 5 R 5 , —NR 5 C(O)NHR 5 , —SH, —SR 5 , —S(O)H, —S(O)R 5 , —SO 2 R 5 , —SO 2 NH 2 , —SO 2 NHR 5 , —SO 2 NR 5 R 5 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —CN, —CO 2 H, —CO 2 R 5 , —CHO, —C(O)R 5 , —C(O)NH 2 , —C(O)NHR 5 , —C(O)NR 5 R 5 , —CONHSO 2 H, —C(O)NHSO 2 R 5 , —C(O)NR 5 SO 2 R 5 , cyclic C 3 -C 7  alkylamino, imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl and azetidinyl; wherein each of the groups imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl and azetidinyl are optionally substituted by one or more of the following groups: C 1-6  alkyl, C 2-6  alkenyl, C 2-6  alkynyl, C 3-7  cyclic alkyl, halo, —OH, —OR 7 , —OC(O)R 7 , —OC(O)NH 2 —OC(O)NHR 7 , —OC(O)NR 7 R 7 , —OP(O)(OH) 2 , —OP(O)(OR 7 ) 2 , —NO 2 , —NH 2 , —NHR 7 , —NR 7 R 7 , —N + (O − ) R 7 R 7 , —NHC(O)H, —NHC(O)R 7 , —NR 7 C(O)R 7 , —NHC(O)NH 2 , —NHC(O)NR 7 R 7 , —NR 7 C(O)NHR 7 , —SH, —SR 7 , —S(O)H, —S(O)R 7 , —SO 2 R 7 , —SO 2 NH 2 , —SO 2 NHR 7 , —SO 2 NR 7 R 7 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 7 , —CHO, —C(O)R 7 , —C(O)NH 2 , —C(O)NHR 7 , —C(O)NR 7 R 7 , —CONHSO 2 H, —C(O)NHSO 2 R 7 , —C(O)NR 7 SO 2 R 7 , an optionally substituted aryl, and an optionally substituted heteroaryl group having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; and wherein the one or more optional substituents for each of said aryl and heteroaryl groups are each independently selected from the following groups: C 1-6  alkyl, C 2-6  alkenyl, C 2-6  alkynyl or C 3-7  cyclic alkyl, halo, —OH, —OR 8 , —OC(O)R 8 , —OC(O)NH 2 , —OC(O)NHR 8 , —OC(O)NR 8 R 8 , —OP(O)(OH) 2 , —OP(O)(OR 8 ) 2 , —NO 2 , —NH 2 , —NHR 8 , —NR 8 R 8 , —N + (O)R 8 R 8 , —NHC(O)H, —NHC(O)R 8 , —NR 3 C(O)R 8 , —NHC(O)NH 2 , —NHC(O)NR 8 R 8 , —NR 8 C(O)NHR 8 , —SH, —SR 8 , —S(O)H, —S(O)R 8 , —SO 2 R 8 , —SO 2 NH 2 , —SO 2 NHR 8 , —SO 2 NR 8 R 8 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 8 , —CHO, —C(O)R 8 , —C(O)NH 2 , —C(O)NHR 8 , —C(O)NR 8 R 8 , —CONHSO 2 H, —C(O)NHSO 2 R 8 , and —C(O)NR 8 SO 2 R 8 ; wherein each R 5 , R 7  and R 8  is independently selected from a C 1-6  alkyl group, a C 2-6  alkenyl group, a C 2-6  alkynyl group and a C 3-7  cyclic alkyl group; and 
         (b) an optionally substituted aryl, and an optionally substituted heteroaryl group having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; and wherein the one or more optional substituents are each independently selected from the same optional substituents as those defined in (a) above for R; 
         R 9  and R 10  are each independently selected from any of the groups defined in paragraphs (a) to (d) below, with the proviso that at least one of R 9  and R 10  is selected from any of the groups defined in paragraphs (c) and (d) below: 
         (a) H, an optionally substituted C 1-6  alkyl group, an optionally substituted C 2-6  alkenyl group, an optionally substituted C 2-6  alkynyl group, and an optionally substituted C 3-7  cyclic alkyl group; wherein the one or more optional substituents for each of said alkyl, alkenyl, alkynyl and cyclic alkyl are each independently selected from the following groups: halo, —OH, —OR 11 , —OC(O)R 11 , —OC(O)NH 2 , —OC(O)NHR 11 , —OC(O)NR 11 R 11 , —OP(O)(OH) 2 , —OP(O)(OR 11 ) 2 , —NO 2 , —NH 2 , —NHR 11 , —NR 11 R 11 , —N + (O)R 11 R 11 , —NHC(O)H, —NHC(O)R 11 , —NR 11 C(O)R 11 , —NHC(O)NH 2 , —NHC(O)NR 11 R 11 , —NR 11 C(O)NHR 11 , —SH, —SR 11 , —S(O)H, —S(O)R 11 , —SO 2 R 11 , —SO 2 NH 2 , —SO 2 NHR 11 , —SO 2 NR 11 R 11 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 11 , —CHO, —C(O)R 11 , —C(O)NH 2 , —C(O)NHR 11 , —C(O)NR 11 R 11 , —CONHSO 2 H, —C(O)NHSO 2 R 11 , —C(O)NR 11 SO 2 R 11 , cyclic C 3 -C 7  alkylamino, imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl, azetidinyl, aryl, and heteroaryl having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; wherein each of the groups cyclic C 3 -C 7  alkylamino, imidazolyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl, azepanyl, pyrrolidinyl azetidinyl, aryl and heteroaryl are optionally substituted by one or more of the following groups: C 1-6  alkyl, C 2-6  alkenyl, C 2-6  alkynyl, C 3-7  cyclic alkyl, halo, —OH, —OR 13 , —OC(O)R 13 , —OC(O)NH 2 , —OC(O)NHR 13 , —OC(O)NR 13 R 13 , —OP(O)(OH) 2 , —OP(O)(OR 13 ) 2 , —NO 2 , —NH 2 , —NHR 13 , —NR 13 R 13 , —N + (O)R 13 R 13 , —NHC(O)H, —NHC(O)R 13 , —NR 13 C(O)R 13 , —NHC(O)NH 2 , —NHC(O)NR 13 R 13 , —NR 13 C(O)NHR 13 , —SH, —SR 13 , —S(O)H, —S(O)R 13 , —SO 2 R 13 , —SO 2 NH 2 , —SO 2 NHR 13 , —SO 2 NR 13 R 13 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , OCHF 2 , —SCF 3 , —SCF 2 H, —CN, —CO 2 H, —CO 2 R 13 , —CHO, —C(O)R 13 , —C(O)NH 2 , —C(O)NHR 13 , —C(O)NR 13 R 13 , —CONHSO 2 H, —C(O)NHSO 2 R 13 , and —C(O)NR 13 SO 2 R 13 ; wherein each R 11  and R 13  is independently selected from a C 1-6  alkyl group, a C 2-6  alkenyl group, a C 2-6  alkynyl group and a C 3-7  cyclic alkyl group; 
         (b) an optionally substituted aryl, and an optionally substituted heteroaryl group having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S; and wherein the one or more optional substituents for each of said aryl and heteroaryl are each independently selected from the same optional substituents as those defined in (a) above for R 9  and R 10 ; 
         (c) —C(O)R 14 , —C(O)OR 14 , —C(O)NR 15 R 16 , —C(O)SR 14 , —C(S)R 14 , —C(S)OR 14  C(S)NR 15 R 16 , and —C(S)SR 14 , wherein each R 14 , R 15  and R 16  is independently selected from the group consisting of H, optionally substituted C 1-6  alkyl, optionally substituted C 2-6  alkenyl, optionally substituted C 2-6  alkynyl, optionally substituted C 3-7  cyclic alkyl, optionally substituted aryl, and optionally substituted heteroaryl having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S, and wherein the one or more optional substituents for each of said alkyl, alkenyl, alkynyl, cyclic alkyl, aryl and heteroaryl for R 14 , R 15  and R 16  are each independently selected from the same optional substituents as those defined in (a) above for R 9  and R 10 ; and 
         (d) —SO 2 (CRR) n R 17 , wherein n is an integer of from 0 to 6, each R is independently selected from the groups defined above for R, and R 17  is optionally substituted aryl or optionally substituted heteroaryl having up to 12 carbon atoms and having one or more heteroatoms in its ring system which are each independently selected from O, N and S, and wherein the one or more optional substituents for each of said aryl and heteroaryl are independently selected from the same optional substituents as those defined in (a) above for R 9  and R 10 ; and —SO 2 R 18 , wherein R 18  is optionally substituted C 1-6 alkyl or optionally substituted C 3-7  cyclic alkyl, wherein the one or more optional substituents for each of said alkyl and cyclic alkyl are each independently selected from those defined in (a) above for R 9  and R 10 ; 
         with the proviso that at least one of R 1 , R 2 , R 3  and R 4 , where present, is other than H or methyl, and 
         with the further proviso that the compound is not selected from the following: 
         2-Bromo-N-(5-chloro-4,6-dimethylisoxazolo[5,4-b]pyridin-3-yl)acetamide, 
         N-(6-Phenyl-4-(trifluoromethyl)isoxazolo[5,4-b]pyridin-3-yl)cyclopropanecarboxamide, and 
         2-Phenyl-N-(6-phenyl-4-(trifluoromethyl)isoxazolo[5,4-b]pyridin-3-yl)acetamide. 
       
     
     
         35 - 70 . (canceled) 
     
     
         71 . A method of (a) treating cancer, (b) inhibiting indoleamine 2,3-dioxygenase 1 (IDO1) and/or tryptophan 2,3-dioxygenase (TDO), or (c) treating a condition or disorder selected from the group consisting of: an inflammatory condition, an infectious disease, a central nervous system disease or disorder, coronary heart disease, chronic renal failure, post anaesthesia cognitive dysfunction, a condition or disorder relating to female reproductive health, and cataracts in a warm blooded animal, including a human, comprising administering to the animal a therapeutically effective amount of a compound of Formula I, as defined in  claim 1 , or a pharmaceutically acceptable salt thereof. 
     
     
         72 - 80 . (canceled)