A compound of Formula (Ia), or a pharmaceutically acceptable salt or tautomer thereof, wherein: A is CR 3; X 1 is CR 8; X 2 is CR 9; X 3 is CR 10; R 2, R 3, R 4, R 5 and R 6 are each, independently, hydrogen, halogen, C 1 -C 6 haloalkyl, NO 2, NR a R b, OH, O(C 1 -C 6 alkyl), S(C 1 -C 6 alkyl), O(C 1 -C 6 haloalkyl), or S(C 1 -C 6 haloalkyl); or R 2 and R 3 together with the carbon atoms to which they attach form a C 6 aryl ring, or R 5 and R 6 together with the carbon atoms to which they attach form a C 6 aryl ring, or R 3 and R 4 together with the carbon atoms to which they attach form a C 6 aryl ring, or R 4 and R 5 together with the carbon atoms to which they attach form a C 6 aryl ring, characterized in that at least one of R 2, R 3, R 4, R 5 and R 6 is O(C 1 -C 6 alkyl) and at least one of R 2, R 3, R 4, R 5 and R 6 is fluorine; R a and R b are each, independently, hydrogen or C 1 -C 6 alkyl; R 8, R 9, R 10, and Z are each, independently, hydrogen, halogen, OH, or O(C 1 -C 6 alkyl); R 11 is -NH-(CH 2) q -R q wherein: q is 2 or 3; R 4 is N-morpholino, 1-piperazinyl or 1-(4-N-(R N))piperazinyl; and R N is C 1 -C 5 alkyl; and R 12 is hydrogen or C 1 -C 6 alkyl; wherein, a) when R 2 is fluorine or chlorine, q is 2 and R 4 is N-morpholino, then at least one of R 3, R 4, R 5 and R 6 is not hydrogen or halogen; and three of R 2, R 3, R 4, R 5 and R 6 are hydrogen; or b) when R 2 is fluorine or chlorine, q is 2 and R 4 is N-morpholino, then at least one of R 8, R 9, R 10, and Z is not hydrogen and R 8 is not OCH 3; or c) when R 2 is fluorine or chlorine, then R 4 is 1-(4-N-(R N))piperazinyl. A is CR 3; X 1 is CR 8; X 2 is CR 9; X 3 is CR 10; R 2, R 3, R 4, R 5 and R 6 are each, independently, hydrogen, halogen, C 1 -C 6 haloalkyl, NO 2, NR a R b, OH, O(C 1 -C 6 alkyl), S(C 1 -C 6 alkyl), O(C 1 -C 6 haloalkyl), or S(C 1 -C 6 haloalkyl); or R 2 and R 3 together with the carbon atoms to which they attach form a C 6 aryl ring, or R 5 and R 6 together with the carbon atoms to which they attach form a C 6 aryl ring, or R 3 and R 4 together with the carbon atoms to which they attach form a C 6 aryl ring, or R 4 and R 5 together with the carbon atoms to which they attach form a C 6 aryl ring, characterized in that at least one of R 2, R 3, R 4, R 5 and R 6 is O(C 1 -C 6 alkyl) and at least one of R 2, R 3, R 4, R 5 and R 6 is fluorine; R a and R b are each, independently, hydrogen or C 1 -C 6 alkyl; R 8, R 9, R 10, and Z are each, independently, hydrogen, halogen, OH, or O(C 1 -C 6 alkyl); R 11 is -NH-(CH 2) q -R q wherein: q is 2 or 3; R 4 is N-morpholino, 1-piperazinyl or 1-(4-N-(R N))piperazinyl; and R N is C 1 -C 5 alkyl; and q is 2 or 3; R 4 is N-morpholino, 1-piperazinyl or 1-(4-N-(R N))piperazinyl; and R N is C 1 -C 5 alkyl; and R 12 is hydrogen or C 1 -C 6 alkyl; wherein, a) when R 2 is fluorine or chlorine, q is 2 and R 4 is N-morpholino, then at least one of R 3, R 4, R 5 and R 6 is not hydrogen or halogen; and three of R 2, R 3, R 4, R 5 and R 6 are hydrogen; or b) when R 2 is fluorine or chlorine, q is 2 and R 4 is N-morpholino, then at least one of R 8, R 9, R 10, and Z is not hydrogen and R 8 is not OCH 3; or c) when R 2 is fluorine or chlorine, then R 4 is 1-(4-N-(R N))piperazinyl. a) when R 2 is fluorine or chlorine, q is 2 and R 4 is N-morpholino, then at least one of R 3, R 4, R 5 and R 6 is not hydrogen or halogen; and three of R 2, R 3, R 4, R 5 and R 6 are hydrogen; or b) when R 2 is fluorine or chlorine, q is 2 and R 4 is N-morpholino, then at least one of R 8, R 9, R 10, and Z is not hydrogen and R 8 is not OCH 3; or c) when R 2 is fluorine or chlorine, then R 4 is 1-(4-N-(R N))piperazinyl.