A compound of the formula (I): ** Formula ** a pharmaceutically acceptable salt, solvate, isotope, polymorph or tautomer thereof, wherein A is a radical selected from A1, A2, A3 and A4； ** Formula ** A1 is ** Formula ** A2 is ** Formula ** A3 is ** Formula ** A4 is ** Formula ** R1 and R2 are independently selected from hydrogen, C1-4alkyl, haloC1-4alkyl, hydroxyC1-4alkyl and C1-4alkoxyC1-4alkyl； R3, R4, R5, R6 and R7 are independently selected from hydrogen, -OH, halogen, C1-6alkyl, C3-6cycloalkyl, -NR12R13, -N (R12) COR13, -N (R12) SO2R13, haloC1-6alkyl, hydroxyC1 -6alkyl, C1-4alkoxy, C1-4alkoxyC1-6alkyl, -COOR12, -CN, -CONR12R13, -SO2-C1-4alkyl, -SO2-O-C1-4alkyl and -SO2-NR12R13； R8 is selected from C1-6alkyl, C2-6alkenyl, C2-6alkynyl, haloC1-6alkyl, hydroxyC1-4alkyl, C1-4alkoxy, C1-4alkoxyC1-4alkyl, C3-6cycloalkylC1-4alkyl, PhC1-4alkyl and -C1Ralkyl-CON13 ； R9, R10 and R11 are independently selected from hydrogen, C1-6alkyl, C3-6cycloalkylC0-4alkyl, -NR12R13, -N (R12) COR13, -N (R12) SO2R13, haloC1-6alkyl, hydroxyC1-6alkyl, C1-4alkoxy, C1-4alkoxyC1-6alkyl, -COOR12, -CN, -CONR12R13, -SO2-C1-4alkyl, -SO2-O-C1-4alkyl and -SO2-NR12R13； and each R12 and R13 are independently selected from hydrogen and C1-4alkyl； wherein the term C3-6-cycloalkyl, as a group or as part of a group, means a monocyclic, non-aromatic hydrocarbon ring, comprising from 3 to 6 carbon atoms, which may be optionally substituted by one or more substituents independently selected from C1-4alkyl, C1-4alkoxy and halogen； and where the term Ph means a phenyl group that may be optionally substituted by one or more substituents independently selected from C1-4alkyl, C1-4alkoxy and halogen provided the following products are excluded: 1-methyl-6-oxo-1 acid , 6-dihydro-pyridine-2-carboxylic acid N'-phenylhydrazide, 1-benzyl-2-oxo-1,2-dihydro-pyridine-3-carboxylic acid N '- (2- (trifluoromethyl) phenyl) -hydrazide, acid 1-Benzyl-4,6-dimethyl-2-oxo-1,2-dihydro-pyridine-3-carboxylic N'-phenyl-hydrazide, 1-
