A compound selected from compounds of Formula ( Ia) and pharmaceutically acceptable salts, solvates, hydrates, and N -oxides thereof: wherein: X is -SO 2 - or absent; R 1 is selected from: aryl, C 1 -C 6 -alkylene-aryl, C 1 -C 6 -alkylene-heteroaryl, C 3 -C 7 cycloalkyl, heteroaryl, and heterocyclyl; each optionally substituted with one or more substituents selected from: C 1 -C 6 alkoxy, C 1 -C 6 alkoxycarbonyl, C 1 -C 7 alkyl, C 1 -C 6 alkylamino, C 1 -C 6 alkylcarboxamide, C 1 -C 6 alkylsulfonamido, C 1 -C 6 alkylsulfonyl, amino, aryloxy, arylsulfonyl, carboxamide, carbamimidoyl, carboxy, cyano, C 3 -C 7 cycloalkyl, C 2 -C 8 dialkylamino, C 2 -C 8 dialkylsulfamoyl, C 1 -C 6 haloalkoxy, C 1 -C 6 haloalkyl, halogen, heterocyclyl, hydroxycarbamimidoyl, hydroxyl, oxo, and sulfamoyl; and wherein said C 1 -C 6 alkoxy, C 1 -C 7 alkyl, C 1 -C 6 alkylamino, aryloxy, C 3 -C 7 cycloalkyl, and C 2 -C 8 dialkylamino are each optionally substituted with one or more substituents selected from: amino, C 1 -C 6 alkoxy, C 1 -C 6 alkylamino, C 1 -C 6 alkylcarboxamide, carboxy, -Y-C 1 -C 6 -alkylene-Z optionally substituted with oxo, C 3 -C 7 cycloalkyl, cyano, C 2 -C 6 dialkylamino, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkylamino, heterocyclyl, hydroxyl, oxo, and phenyl; Y is selected from: -O- and -NH-; Z is selected from: C 1 -C 6 alkoxy, amino, C 1 -C 6 alkylamino, cyano, C 2 -C 6 dialkylamino, hydroxyl, and phenyl; R 2a is H or selected from: C 1 -C 6 alkoxy, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, and heterocyclyl; each optionally substituted with one or more substituents selected from: C 1 -C 6 alkoxy, C 1 -C 6 alkylamino, C 1 -C 6 alkyl, C 1 -C 6 alkylenehydroxyl, amino, C 3 -C 7 cycloalkyl, cyano, C 2 -C 8 dialkylamino, heterocyclyl optionally substituted with one oxo group, halogen, hydroxyl, and oxo; and R 2b is H or C 1 -C 6 alkyl. X is -SO 2 - or absent; R 1 is selected from: aryl, C 1 -C 6 -alkylene-aryl, C 1 -C 6 -alkylene-heteroaryl, C 3 -C 7 cycloalkyl, heteroaryl, and heterocyclyl; each optionally substituted with one or more substituents selected from: C 1 -C 6 alkoxy, C 1 -C 6 alkoxycarbonyl, C 1 -C 7 alkyl, C 1 -C 6 alkylamino, C 1 -C 6 alkylcarboxamide, C 1 -C 6 alkylsulfonamido, C 1 -C 6 alkylsulfonyl, amino, aryloxy, arylsulfonyl, carboxamide, carbamimidoyl, carboxy, cyano, C 3 -C 7 cycloalkyl, C 2 -C 8 dialkylamino, C 2 -C 8 dialkylsulfamoyl, C 1 -C 6 haloalkoxy, C 1 -C 6 haloalkyl, halogen, heterocyclyl, hydroxycarbamimidoyl, hydroxyl, oxo, and sulfamoyl; and wherein said C 1 -C 6 alkoxy, C 1 -C 7 alkyl, C 1 -C 6 alkylamino, aryloxy, C 3 -C 7 cycloalkyl, and C 2 -C 8 dialkylamino are each optionally substituted with one or more substituents selected from: amino, C 1 -C 6 alkoxy, C 1 -C 6 alkylamino, C 1 -C 6 alkylcarboxamide, carboxy, -Y-C 1 -C 6 -alkylene-Z optionally substituted with oxo, C 3 -C 7 cycloalkyl, cyano, C 2 -C 6 dialkylamino, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkylamino, heterocyclyl, hydroxyl, oxo, and phenyl; Y is selected from: -O- and -NH-; Z is selected from: C 1 -C 6 alkoxy, amino, C 1 -C 6 alkylamino, cyano, C 2 -C 6 dialkylamino, hydroxyl, and phenyl; R 2a is H or selected from: C 1 -C 6 alkoxy, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, and heterocyclyl; each optionally substituted with one or more substituents selected from: C 1 -C 6 alkoxy, C 1 -C 6 alkylamino, C 1 -C 6 alkyl, C 1 -C 6 alkylenehydroxyl, amino, C 3 -C 7 cycloalkyl, cyano, C 2 -C 8 dialkylamino, heterocyclyl optionally substituted with one oxo group, halogen, hydroxyl, and oxo; and R 2b is H or C 1 -C 6 alkyl.