A compound of Formula I, or a pharmaceutically acceptable salt thereof: wherein A3 is represented by Formula II or Formula III: wherein Y is N or CH, wherein CH may be substituted with R c1 if R c1 is present in the structure; R 1 is CH3; Each R a is independently CF 3, CH 3, -OCF 3, Cl, F, cyclopropyl, or -CN; R c is azetidine, azetidinone, pyrrolidine, piperidine, morpholine, imidazole, pyrazole, isothiazolidine 1,1-dioxide, a morpholine ring comprising a methylene group bridging between two ring members, or a pyrrolidine ring comprising a fused cyclopropyl ring, wherein R c comprises one N which is bonded to the heteroaromatic ring to which R c is connected and wherein R c is optionally substituted with 1-3 substituent groups which are independently halogen, -OH, -CH 3, -OCH 3, -CF 3, or -OCF 3; Each R c1 is independently -CH 3 or Br; R b is H, -C 1-2 alkyl, -OCH 3, Cl, F, or -O-cyclopropyl; R b1 is F; X is: (a) Cl, -CH 2 CN, -(CH 2) 1 - 3 OH, -(CH 2) 1-3 OCH 3, -CH(CH 3) 2 optionally substituted with 1-3 F and one -OH, -cyclopentyl-OH, -cyclohexyl-CN, or phenyl substituted with 2 substituents which are -OH and -C(=O)CH 3; (b) D 1, wherein D 1 is -CO 2 H or -CO 2 C 1-4 alkyl; (c) -C 1-4 alkyl-D 2, wherein D 2 is -CO 2 H, -CO 2 C 1-4 alkyl, or -C(=O)NR 2 R 3; (d) -C 3-6 cycloalkyl-D 2; (e) -C 3-6 cycloalkyl-CH 2 -D 1; (f) -phenyl-D 1, wherein phenyl is optionally substituted with 1-3 substituent groups which are independently halogen or -CH 3; (g) -HET -D 1, wherein HET is a 5-6 membered heteroaromatic ring having 1-2 heteroatoms which are independently N, O, or S, wherein HET is optionally substituted with 1-3 substituents which are independently halogen, -CH 3 -CF 3 -OCH 3 or -OCF 3; or (h) - 1-2 -HET, wherein HET is a 5-membered heteroaromatic ring having 2-4 N atoms, wherein HET is optionally substituted with 1-2 groups which are independently -CH 3 or halogen; R 2 and R 3 are each independently H or -C 1-3 alkyl, or R 2 and R 3 are optionally joined to form a bridging group having 3-5 carbons, thereby yielding a 4-6 membered cyclic amide group; d is an integer from 0-2; e is an integer from 1-3; and f is an integer from 0-2. wherein A3 is represented by Formula II or Formula III: wherein Y is N or CH, wherein CH may be substituted with R c1 if R c1 is present in the structure; R 1 is CH3; Each R a is independently CF 3, CH 3, -OCF 3, Cl, F, cyclopropyl, or -CN; R c is azetidine, azetidinone, pyrrolidine, piperidine, morpholine, imidazole, pyrazole, isothiazolidine 1,1-dioxide, a morpholine ring comprising a methylene group bridging between two ring members, or a pyrrolidine ring comprising a fused cyclopropyl ring, wherein R c comprises one N which is bonded to the heteroaromatic ring to which R c is connected and wherein R c is optionally substituted with 1-3 substituent groups which are independently halogen, -OH, -CH 3, -OCH 3, -CF 3, or -OCF 3; Each R c1 is independently -CH 3 or Br; R b is H, -C 1-2 alkyl, -OCH 3, Cl, F, or -O-cyclopropyl; R b1 is F; X is: (a) Cl, -CH 2 CN, -(CH 2) 1 - 3 OH, -(CH 2) 1-3 OCH 3, -CH(CH 3) 2 optionally substituted with 1-3 F and one -OH, -cyclopentyl-OH, -cyclohexyl-CN, or phenyl substituted with 2 substituents which are -OH and -C(=O)CH 3; (b) D 1, wherein D 1 is -CO 2 H or -CO 2 C 1-4 alkyl; (c) -C 1-4 alkyl-D 2, wherein D 2 is -CO 2 H, -CO 2 C 1-4 alkyl, or -C(=O)NR 2 R 3; (d) -C 3-6 cycloalkyl-D 2; (e) -C 3-6 cycloalkyl-CH 2 -D 1; (f) -phenyl-D 1, wherein phenyl is optionally substituted with 1-3 substituent groups which are independently halogen or -CH 3; (g) -HET -D 1, wherein HET is a 5-6 membered heteroaromatic ring having 1-2 heteroatoms which are independently N, O, or S, wherein HET is optionally substituted with 1-3 substituents which are independently halogen, -CH 3 -CF 3 -OCH 3 or -OCF 3; or (h) - 1-2 -HET, wherein HET is a 5-membered heteroaromatic ring having 2-4 N atoms, wherein HET is optionally substituted with 1-2 groups which are independently -CH 3 or halogen; (a) Cl, -CH 2 CN, -(CH 2) 1 - 3 OH, -(CH 2) 1-3 OCH 3, -CH(CH 3) 2 optionally substituted with 1-3 F and one -OH, -cyclopentyl-OH, -cyclohexyl-CN, or phenyl substituted with 2 substituents which are -OH and -C(=O)CH 3; (b) D 1, wherein D 1 is -CO 2 H or -CO 2 C 1-4 alkyl; (c) -C 1-4 alkyl-D 2, wherein D 2 is -CO 2 H, -CO 2 C 1-4 alkyl, or -C(=O)NR 2 R 3; (d) -C 3-6 cycloalkyl-D 2; (e) -C 3-6 cycloalkyl-CH 2 -D 1; (f) -phenyl-D 1, wherein phenyl is optionally substituted with 1-3 substituent groups which are independently halogen or -CH 3; (g) -HET -D 1, wherein HET is a 5-6 membered heteroaromatic ring having 1-2 heteroatoms which are independently N, O, or S, wherein HET is optionally substituted with 1-3 substituents which are independently halogen, -CH 3 -CF 3 -OCH 3 or -OCF 3; or (h) - 1-2 -HET, wherein HET is a 5-membered heteroaromatic ring having 2-4 N atoms, wherein HET is optionally substituted with 1-2 groups which are independently -CH 3 or halogen; R 2 and R 3 are each independently H or -C 1-3 alkyl, or R 2 and R 3 are optionally joined to form a bridging group having 3-5 carbons, thereby yielding a 4-6 membered cyclic amide group; d is an integer from 0-2; e is an integer from 1-3; and f is an integer from 0-2.