A compound of Formula (Ib): or a pharmaceutically acceptable salt thereof, wherein: is selected from the group consisting of X 15 is N or CR 43 ; X 16 is N or CR 44 ; X 17 is N or CR 45 ; X 18 is N or CR 46 ; X 19 is N or CR 47 ; R 43 , R 44 , R 45 , R 46 and R 47 are independently selected from the group consisting of hydrogen, cyano, halo, hydroxy, azido, nitro, carboxy, oxo, sulfinyl, sulfanyl, sulfonyl, optionally substituted alkoxy, optionally substituted cycloalkyloxy, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted heterocycloalkyloxy, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocycloalkyl, optionally substituted amino, optionally substituted acyl, optionally substituted alkoxycarbonyl, optionally substituted aminocarbonyl, optionally substituted aminosulfonyl, optionally substituted carbamimidoyl and E; E is selected from the group consisting of: and and R 1 and R 6 are each independently selected from the group consisting of hydrogen, cyano, halo, hydroxy, azido, nitro, carboxy, oxo, sulfinyl, sulfanyl, sulfonyl, optionally substituted alkoxy, optionally substituted cycloalkyloxy, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted heterocycloalkyloxy, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocycloalkyl, optionally substituted amino, optionally substituted acyl, optionally substituted alkoxycarbonyl, optionally substituted aminocarbonyl, optionally substituted aminosulfonyl and optionally substituted carbamimidoyl. is selected from the group consisting of X 15 is N or CR 43 ; X 16 is N or CR 44 ; X 17 is N or CR 45 ; X 18 is N or CR 46 ; X 19 is N or CR 47 ; R 43 , R 44 , R 45 , R 46 and R 47 are independently selected from the group consisting of hydrogen, cyano, halo, hydroxy, azido, nitro, carboxy, oxo, sulfinyl, sulfanyl, sulfonyl, optionally substituted alkoxy, optionally substituted cycloalkyloxy, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted heterocycloalkyloxy, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocycloalkyl, optionally substituted amino, optionally substituted acyl, optionally substituted alkoxycarbonyl, optionally substituted aminocarbonyl, optionally substituted aminosulfonyl, optionally substituted carbamimidoyl and E; E is selected from the group consisting of: and and R 1 and R 6 are each independently selected from the group consisting of hydrogen, cyano, halo, hydroxy, azido, nitro, carboxy, oxo, sulfinyl, sulfanyl, sulfonyl, optionally substituted alkoxy, optionally substituted cycloalkyloxy, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted heterocycloalkyloxy, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocycloalkyl, optionally substituted amino, optionally substituted acyl, optionally substituted alkoxycarbonyl, optionally substituted aminocarbonyl, optionally substituted aminosulfonyl and optionally substituted carbamimidoyl. <EOS>