A compound having structural Formula I, or a pharmaceutically acceptable salt thereof: wherein: is an 8- or 9-membered heteroaryl; R a and R b are independently selected at each occurrence from the group consisting of -H and -C 1 -C 6 alkyl; R c is independently selected at each occurrence from the group consisting of -C 1 -C 6 alkyl, -CF 3, and aryl; R 1 is independently selected at each occurrence from the group consisting of -H, halo, aryl, heteroaryl, -C 1 -C 6 alkyl, -C 3 - 10 cycloalkyl, -OR, -NO 2, -CN, -CO 2 R a, -NR a R b, -S p R c, thioxo, azido, -C(=O)R a, -OC n R a, -OC(=O)OR a, -OC(=O)NR a R b, -SO 2 NR a NR b -NR a (C=O) n R b, -NR a SO 2 R b, -NR a C(=O)OR b, -NR a C NR a R b, -NR a SO 2 NR a R b, -C 2-10 alkenyl, and -C 2-10 alkynyl, said aryl, heteroaryl, alkyl, cycloalkyl, alkenyl and alkynyl optionally being substituted with one to three substituents selected from halo, -C 1 -C 6 alkyl, -OR, oxo, aryl, heteroaryl, -C 3 - 10 cycloalkyl, -NO 2 -CN, -CO 2 R a NR a R b, -S p R c, thioxo, azido, -C(=O)R a, -O(C=O) n R a, -OC(=O)OR a, -OC(=O)NR a Rb, -SO 2 NR a NR b -NR a (C=O) n R b, -NR a SO 2 R b, -NR a C(=O)OR b -NR a C(=O)NR a R b, -NR a SO 2 NR a R b and -CF 3; R 2 is selected from the group consisting of -C 1 -C 6 alkyl, -(CR a 2) r OR, -(CR a 2) r S p R c, -(CR a 2) r CF 3, -(CR a) r -C 3 - 10 cycloalkyl, -(CR a 2) r aryl, -(CR a 2) r heteroaryl, -(CR a 2) r- C 2-10 alkenyl, -(CR a 2) r- C 2-10 alkynyl, and -(CR a 2) r C Oalkyl, said alkyl, cycloalkyl, aryl, hetetoaryl, alkenyl and alkynyl being optionally substituted with one to three substituents selected from halo, -C 1 -C 6 alkyl,-CF 3, -CN and -OR; R is independently selected at each occurrence from the group consisting of -H, -C 1 -C 6 alkyl, -CF 3, and aryl; R 3 and R 4 are independently selected from the group consisting of -H and -C 1 -C 6 alkyl; when R 3 and R 4 are C 1 -C 6 alkyl they may optionally be joined to form a cycloalkyl; m is 0, 1, 2, or 3; p is 0,1 or 2; r is 0, 1, 2, 3, 4, 5, or 6; and z is 0 or 1, wherein 'aryl' is a mono- or bicyclic aromatic ring containing 6-12 carbon atoms; 'heteroaryl' is a mono- or bicyclic aromatic ring or ring system having 5 to 10 atoms and containing at least one heteroatom selected from O, S, and N; and 'cycloalkyl' is cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl or decahydronaphthyl. is an 8- or 9-membered heteroaryl; R a and R b are independently selected at each occurrence from the group consisting of -H and -C 1 -C 6 alkyl; R c is independently selected at each occurrence from the group consisting of -C 1 -C 6 alkyl, -CF 3, and aryl; R 1 is independently selected at each occurrence from the group consisting of -H, halo, aryl, heteroaryl, -C 1 -C 6 alkyl, -C 3 - 10 cycloalkyl, -OR, -NO 2, -CN, -CO 2 R a, -NR a R b, -S p R c, thioxo, azido, -C(=O)R a, -OC n R a, -OC(=O)OR a, -OC(=O)NR a R b, -SO 2 NR a NR b -NR a (C=O) n R b, -NR a SO 2 R b, -NR a C(=O)OR b, -NR a C NR a R b, -NR a SO 2 NR a R b, -C 2-10 alkenyl, and -C 2-10 alkynyl, said aryl, heteroaryl, alkyl, cycloalkyl, alkenyl and alkynyl optionally being substituted with one to three substituents selected from halo, -C 1 -C 6 alkyl, -OR, oxo, aryl, heteroaryl, -C 3 - 10 cycloalkyl, -NO 2 -CN, -CO 2 R a NR a R b, -S p R c, thioxo, azido, -C(=O)R a, -O(C=O) n R a, -OC(=O)OR a, -OC(=O)NR a Rb, -SO 2 NR a NR b -NR a (C=O) n R b, -NR a SO 2 R b, -NR a C(=O)OR b -NR a C(=O)NR a R b, -NR a SO 2 NR a R b and -CF 3; R 2 is selected from the group consisting of -C 1 -C 6 alkyl, -(CR a 2) r OR, -(CR a 2) r S p R c, -(CR a 2) r CF 3, -(CR a) r -C 3 - 10 cycloalkyl, -(CR a 2) r aryl, -(CR a 2) r heteroaryl, -(CR a 2) r- C 2-10 alkenyl, -(CR a 2) r- C 2-10 alkynyl, and -(CR a 2) r C Oalkyl, said alkyl, cycloalkyl, aryl, hetetoaryl, alkenyl and alkynyl being optionally substituted with one to three substituents selected from halo, -C 1 -C 6 alkyl,-CF 3, -CN and -OR; R is independently selected at each occurrence from the group consisting of -H, -C 1 -C 6 alkyl, -CF 3, and aryl; R 3 and R 4 are independently selected from the group consisting of -H and -C 1 -C 6 alkyl; when R 3 and R 4 are C 1 -C 6 alkyl they may optionally be joined to form a cycloalkyl; m is 0, 1, 2, or 3; p is 0,1 or 2; r is 0, 1, 2, 3, 4, 5, or 6; and z is 0 or 1,