A compound of the formula I: ** Formula ** in which: A is selected from the group consisting of: (1) pyridyl, (2) quinolinyl, (3) naphthyridinyl, (4) thiazolyl, (5) pyridazinyl , (6) oxazolyl, and (7) pyrazolyl, (8) dihydropyrrolopyrazolyl, (9) dihydrocyclopentapyridinyl, (10) imidazopyridazinyl and (11) pyrazolopyrimidinyl； B is selected from the group consisting of: (1) thiazolyl, (2) pyrazolyl, (3) thiadiazolyl, (4) isoxazolyl, (5) isothiazolyl, (6) pyridyl, and (7) pyrimidinyl； R1a, R1b and R1c are independently selected from the group consisting of: (1) hydrogen, (2) halogen, (3) hydroxyl, (4) - (C>； = O) m-On-C1-6 alkyl, where m is 0 or 1, n is 0 or 1 (where if m is 0 on is 0, a bond is present) and where the alkyl is unsubstituted or substituted with one or more substituents selected from R13, (5) - ( C>； = O) m-On-C3-6 cycloalkyl, where the cycloalkyl is unsubstituted or substituted with one or more substituents selected from R13, (6) - (C>； = O) m-C2-4 alkenyl, where the alkenyl is unsubstituted or substituted with one or more substituents selected from R13, (7) - (C>； = O) m-C2-4 alkynyl, where the alkynyl is unsubstituted or substituted with one or more substituents selected from R13, ( 8) - (C>； = O) m-On-phenyl or - (C>； = O) m-On-naphthyl, where phenyl or naphthyl are unsubstituted or substituted with one or more substituents selected from R13, (9 ) - (C>； = O) m-On-heteroaryl, where the heteroaryl is unsubstituted or substituted with u no or more substituents selected from R13, (10) - (C>； = O) m-NR10R11, (11) -S (O) 2-NR10R11, (12) -S (O) q-R12, where q is 0 , 1 or 2 and where R12 is selected from the definitions of R10 and R11, (13) -CO2H, (14) -CN and (15) -NO2； R2a, R2b and R2c are independently selected from the group consisting of: (1) hydrogen, (2) halogen, (3) hydroxyl, (4) - (C>； = O) m-On-C1-6 alkyl, where the alkyl is unsubstituted or substituted with one or more substituents selected from R13, (5) - (C>； = O) m-C3-6 cyc
