A compound of Formula: or a free acid, free base, salt, isotopologue, stereoisomer, racemate, enantiomer, diastereomer or tautomer thereof, wherein: R 1 is heterocyclyl; wherein, heterocyclyl is optionally substituted with one, two or three R 3 substituents and optionally, with one additional R 4 substituent; or, wherein, heterocyclyl is optionally substituted with one, two, three or four R 3 substituents; R 2 is heteroaryl; wherein, heteroaryl is optionally substituted with one, two or three R 6 substituents and optionally, with one additional R 7 substituent; R a is, in each instance, independently selected from hydrogen, halogen or C 1-8 alkyl; R b is hydrogen, halogen, C 1-8 alkyl or C 1-8 alkoxy; R c is hydrogen, halogen or C 1-8 alkyl; R 3 is, in each instance, independently selected from cyano, halogen, hydroxy, oxo, C 1-8 alkyl, halo-C 1-8 alkyl, C 1-8 alkyl-carbonyl, C 1-8 alkoxy, halo-C 1-8 alkoxy, C 1-8 alkoxy-C 1-8 alkyl, C 1-8 alkoxy-carbonyl, amino, C 1-8 alkyl-amino, (C 1-8 alkyl) 2 -amino, amino-C 1-8 alkyl, C 1-8 alkyl-amino-C 1-8 alkyl, (C 1-8 alkyl) 2 -amino-C 1-8 alkyl, amino-C 1-8 alkyl-amino, C 1-8 alkyl-amino-C 1-8 alkyl-amino, (C 1-8 alkyl-amino-C 1-8 alkyl) 2 -amino, (C 1-8 alkyl) 2 -amino-C 1-8 alkyl-amino, [(C 1-8 alkyl) 2 -amino-C 1-8 alkyl] 2 -amino, (C 1-8 alkyl-amino-C 1-8 alkyl)(C 1-8 alkyl)amino, [(C 1-8 alkyl) 2 -amino-C 1-8 alkyl](C 1-8 alkyl)amino, C 1-8 alkoxy-C 1-8 alkyl-amino, (C 1-8 alkoxy-C 1-8 alkyl) 2 -amino, (C 1-8 alkoxy-C 1-8 alkyl)(C 1-8 alkyl)amino, C 1-8 alkyl-carbonyl-amino, C 1-8 alkoxy-carbonyl-amino, hydroxy-C 1-8 alkyl, hydroxy-C 1-8 alkoxy-C 1-8 alkyl, hydroxy-C 1-8 alkyl-amino, (hydroxy-C 1-8 alkyl) 2 -amino or (hydroxy-C 1-8 alkyl)(C 1-8 alkyl)amino; R 4 is C 3-14 cycloalkyl, C 3-14 cycloalkyl-C 1-8 alkyl, C 3-14 cycloalkyl-amino, aryl-C 1-8 alkyl, aryl-C 1-8 alkoxy-carbonyl, aryl-sulfonyloxy-C 1-8 alkyl, heterocyclyl or heterocyclyl-C 1-8 alkyl; wherein, each instance of C 3-14 cycloalkyl, aryl and heterocyclyl is optionally substituted with one, two or three R 5 substituents; R 5 is, in each instance, independently selected from halogen, hydroxy, cyano, nitro, C 1-8 alkyl, halo-C 1-8 alkyl, C 1-8 alkoxy, halo-C 1-8 alkoxy, amino, C 1-8 alkyl-amino, (C 1-8 alkyl) 2 -amino or C 1-8 alkyl-thio; R 6 is, in each instance, independently selected from halogen, hydroxy, cyano, nitro, C 1-8 alkyl, C 2-8 alkenyl, halo-C 1-8 alkyl, hydroxy-C 1-8 alkyl, C 1-8 alkoxy, halo-C 1-8 alkoxy, C 1-8 alkoxy-C 1-8 alkyl, amino, C 1-8 alkyl-amino, (C 1-8 alkyl) 2 -amino or C 1-8 alkyl-thio; and, R 7 is C 3-14 cycloalkyl, C 3-14 cycloalkyl-oxy, aryl, heterocyclyl or heteroaryl. R 1 is heterocyclyl; wherein, heterocyclyl is optionally substituted with one, two or three R 3 substituents and optionally, with one additional R 4 substituent; or, wherein, heterocyclyl is optionally substituted with one, two, three or four R 3 substituents; R 2 is heteroaryl; wherein, heteroaryl is optionally substituted with one, two or three R 6 substituents and optionally, with one additional R 7 substituent; R a is, in each instance, independently selected from hydrogen, halogen or C 1-8 alkyl; R b is hydrogen, halogen, C 1-8 alkyl or C 1-8 alkoxy; R c is hydrogen, halogen or C 1-8 alkyl; R 3 is, in each instance, independently selected from cyano, halogen, hydroxy, oxo, C 1-8 alkyl, halo-C 1-8 alkyl, C 1-8 alkyl-carbonyl, C 1-8 alkoxy, halo-C 1-8 alkoxy, C 1-8 alkoxy-C 1-8 alkyl, C 1-8 alkoxy-carbonyl, amino, C 1-8 alkyl-amino, (C 1-8 alkyl) 2 -amino, amino-C 1-8 alkyl, C 1-8 alkyl-amino-C 1-8 alkyl, (C 1-8 alkyl) 2 -amino-C 1-8 alkyl, amino-C 1-8 alkyl-amino, C 1-8 alkyl-amino-C 1-8 alkyl-amino, (C 1-8 alkyl-amino-C 1-8 alkyl) 2 -amino, (C 1-8 alkyl) 2 -amino-C 1-8 alkyl-amino, [(C 1-8 alkyl) 2 -amino-C 1-8 alkyl] 2 -amino, (C 1-8 alkyl-amino-C 1-8 alkyl)(C 1-8 alkyl)amino, [(C 1-8 alkyl) 2 -amino-C 1-8 alkyl](C 1-8 alkyl)amino, C 1-8 alkoxy-C 1-8 alkyl-amino, (C 1-8 alkoxy-C 1-8 alkyl) 2 -amino, (C 1-8 alkoxy-C 1-8 alkyl)(C 1-8 alkyl)amino, C 1-8 alkyl-carbonyl-amino, C 1-8 alkoxy-carbonyl-amino, hydroxy-C 1-8 alkyl, hydroxy-C 1-8 alkoxy-C 1-8 alkyl, hydroxy-C 1-8 alkyl-amino, (hydroxy-C 1-8 alkyl) 2 -amino or (hydroxy-C 1-8 alkyl)(C 1-8 alkyl)amino; R 4 is C 3-14 cycloalkyl, C 3-14 cycloalkyl-C 1-8 alkyl, C 3-14 cycloalkyl-amino, aryl-C 1-8 alkyl, aryl-C 1-8 alkoxy-carbonyl, aryl-sulfonyloxy-C 1-8 alkyl, heterocyclyl or heterocyclyl-C 1-8 alkyl; wherein, each instance of C 3-14 cycloalkyl, aryl and heterocyclyl is optionally substituted with one, two or three R 5 substituents; R 5 is, in each instance, independently selected from halogen, hydroxy, cyano, nitro, C 1-8 alkyl, halo-C 1-8 alkyl, C 1-8 alkoxy, halo-C 1-8 alkoxy, amino, C 1-8 alkyl-amino, (C 1-8 alkyl) 2 -amino or C 1-8 alkyl-thio; R 6 is, in each instance, independently selected from halogen, hydroxy, cyano, nitro, C 1-8 alkyl, C 2-8 alkenyl, halo-C 1-8 alkyl, hydroxy-C 1-8 alkyl, C 1-8 alkoxy, halo-C 1-8 alkoxy, C 1-8 alkoxy-C 1-8 alkyl, amino, C 1-8 alkyl-amino, (C 1-8 alkyl) 2 -amino or C 1-8 alkyl-thio; and, R 7 is C 3-14 cycloalkyl, C 3-14 cycloalkyl-oxy, aryl, heterocyclyl or heteroaryl.