A compound of Formula ( I-a): or a pharmaceutically acceptable salt thereof, wherein X is N, Z is NR 4, and Y is CR 5; or X is NR 4, Z is N, and Y is CR 5; or X is CR 5, Z is NR 4, and Y is N; or X is CR 5, Z is N, and Y is NR 4; R G is -CF 3 or -CF 2 H; R 1 is hydrogen, halo, -CN, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, -O-C 1-6 alkyl-O-C 1-6 alkyl, -O-C 1-6 alkyl-carbocyclyl, -O-C 1-6 alkyl-heterocyclyl, -C 1-6 alkyl-carbocyclyl, or -OR A; R 2 is hydrogen, halo, -CN, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, -OCH CH(CH 3) 2, -O-C 1-6 alkyl-O-C 1-6 alkyl,-OCH 2 CH 2 OH, -OCH 2 CF 3 or -OCH 2 CH 2 CH 2 CF 3, -O-C 1-6 alkyl-carbocyclyl, -O-C 1-6 alkyl-heterocyclyl, -O-C 1-6 alkyl-aryl, -O-C 1-6 alkyl-heteroaryl, -C 1-6 alkyl-carbocyclyl or -OR A; R 7 and R 8 are independently selected from the group consisting of hydrogen, halo,-CN, -NO 2, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, aryl, heterocyclyl, heteroaryl, -OR A, -N(R B) 2, and -SR A; wherein at least one of R 7 and R 8 is not hydrogen; each R A is independently selected from the group consisting of hydrogen, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl; each R B is independently selected from the group consisting of hydrogen, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl, or two R B groups are taken together with their intervening atoms to form a heterocyclic ring; R 3 is hydrogen, or C 1-4 alkyl; R 4 is hydrogen; R 5 is hydrogen; and R x is unsubstituted C 1-4 alkyl; wherein, and unless otherwise specified, heterocyclyl or heterocyclic refers to a radical of a 3-10 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur; carbocyclyl or carbocyclic refers to a radical of a non-aromatic cyclic hydrocarbon group having from 3 to 10 ring carbon atoms and zero heteroatoms in the non-aromatic ring system; aryl refers to a radical of a monocyclic or polycyclic aromatic ring system having 6-14 ring carbon atoms and zero heteroatoms provided in the aromatic ring system; and heteroaryl refers to a radical of a 5-10 membered monocyclic or bicyclic 4n+2 aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen and sulfur; alkyl refers to a radical of a straight-chain or branched saturated hydrocarbon group having from 1 to 20 carbon atoms; alkenyl refers to a radical of a straight-chain or branded hydrocarbon group having from 2 to 20 carbon atoms and one or more carbon-carbon double bonds; and alkenyl refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 20 carbon atoms and one or more carbon-carbon triple bonds. X is N, Z is NR 4, and Y is CR 5; or X is NR 4, Z is N, and Y is CR 5; or X is CR 5, Z is NR 4, and Y is N; or X is CR 5, Z is N, and Y is NR 4; R G is -CF 3 or -CF 2 H; R 1 is hydrogen, halo, -CN, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, -O-C 1-6 alkyl-O-C 1-6 alkyl, -O-C 1-6 alkyl-carbocyclyl, -O-C 1-6 alkyl-heterocyclyl, -C 1-6 alkyl-carbocyclyl, or -OR A; R 2 is hydrogen, halo, -CN, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, -OCH CH(CH 3) 2, -O-C 1-6 alkyl-O-C 1-6 alkyl,-OCH 2 CH 2 OH, -OCH 2 CF 3 or -OCH 2 CH 2 CH 2 CF 3, -O-C 1-6 alkyl-carbocyclyl, -O-C 1-6 alkyl-heterocyclyl, -O-C 1-6 alkyl-aryl, -O-C 1-6 alkyl-heteroaryl, -C 1-6 alkyl-carbocyclyl or -OR A; R 7 and R 8 are independently selected from the group consisting of hydrogen, halo,-CN, -NO 2, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, aryl, heterocyclyl, heteroaryl, -OR A, -N(R B) 2, and -SR A; wherein at least one of R 7 and R 8 is not hydrogen; each R A is independently selected from the group consisting of hydrogen, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl; each R B is independently selected from the group consisting of hydrogen, alkyl optionally substituted with one or more halogens, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl, or two R B groups are taken together with their intervening atoms to form a heterocyclic ring; R 3 is hydrogen, or C 1-4 alkyl; R 4 is hydrogen; R 5 is hydrogen; and R x is unsubstituted C 1-4 alkyl;