A compound of formula (1): ** Formula ** where A is a group of the following formula (A-1): ** Formula ** R1a and R1b are the same or different and each is independently C1-6 alkyl which it may be optionally substituted with 1 to 3 halogen atoms； m and n are each independently an integer from 0 to 5； X1 is hydroxyl or aminocarbonyl； Z1 is a single bond, oxygen atom, a sulfur atom, -SO-, -SO2- or -N (R3) -； R2 is cyano, optionally substituted C1-6 alkyl, optionally substituted C3-7 cycloalkyl, optionally substituted C6-10 aryl, optionally substituted C7-16 aralkyl, optionally substituted heterocycle, optionally substituted heterocyclic C1-6 alkyl, mono or polycyclic heteroaryl of 5 optionally substituted 12-membered, optionally substituted 5 to 12-membered mono or polycyclic heteroaryl-C 1-6 alkyl or optionally substituted 5 to 7-membered cyclic amino； with the proviso that if R2 is cyano and optionally substituted 5-7 membered cyclic amino, then Z1 is a single bond； R3 is a hydrogen atom, optionally substituted C1-6 alkyl, optionally substituted C3-7 cycloalkyl, optionally substituted C6-10 aryl, optionally substituted C7-16 aralkyl, optionally substituted heterocycle, optionally substituted heterocyclic C1-6 alkyl, mono or heteroaryl optionally substituted 5 to 12 membered polycyclic, or optionally substituted 5 to 12 membered mono or polycyclic heteroaryl-C 1-6 alkyl； wherein the optionally substituted C6-10 aryl substituent group, optionally substituted 5 to 12 membered mono or polycyclic heteroaryl, optionally substituted C7-16 aralkyl and optionally substituted 5 to 12 membered mono or polycyclic heteroaryl-C1-6 alkyl in R2 is selected from the group consisting of: (1) a halogen atom, (2) cyano, (3) hydroxy, (4) C1-4 alkoxy (in which the alkoxy may be optionally substituted with (a) 1 a 3 halogen atoms, (b) C1-4 alkoxy, (c) carboxy, (d) C1-4 alkoxycarbonyl, (e) C7-16 aralkyloxycarbonyl, (f) mono or di- C 1-6 alkylaminocarbonyl, (g) aminocarbonyl 5-7 membered cy
