A compound represented by formula (I-A), or a pharmaceutically acceptable salt thereof, Wherein R 1 is hydrogen, halogen, cyano or hydroxy; C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylsulfanyl, C 1-6 alkylsulfinyl, C 1-6 alkylsulfonyl or (C 1-6 -alkylsulfonyl)amino, any of which groups may be substituted by one or more substituents; R 2 is hydrogen, cyano, or halogen; or C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylsulfanyl, C 1-6 alkylsulfinyl, C 1-6 alkylsulfonyl, C 1-6 alkylsulfonylamino, (C 1-6 alkylsulfonyl)amino(C 1-6 alkyl), C 1-6 alkylamido, (C 1-6 alkylacyl)amino, (C 1-6 alkylacyl)amino(C 1-6 alkyl), or heteroaryl, any of which groups may be substituted by one or more substituents; or R 1 and R 2 are linked together to form with the adjacent aromatic group a heterocycle of formula (i): wherein R 2b is hydrogen or C 1-6 alkylsulfonyl; R 3 is halogen, C 1-6 alkyl, C 1-6 alkoxy or cyano; R 4 is hydrogen, halogen, C 1-6 alkyl, hydroxy, C 1-6 alkoxy, C 1-6 alkylsulfonyl, C 1-6 alkoxycarbonyloxy or C 1-6 alkylaminocarbonyloxy; R 4' is hydrogen, halogen or C 1-6 alkyl; or R 4 and R 4' together form an oxo group; R 5 is hydrogen, cyano or hydroxy; or C 1-6 alkyl; C 1-6- alkylsulfonyl, C 1-6- alkylsulfonylamino; C 1-6- alkylsulfonylamino(C 1-6 alkyl), heterocycle, C 1-6 alkylacylamino(C 1-6 alkyl), C 1-6 alkylureido(C 1-6 alkyl), C 1-6 alkylcarbamate(C 1-6 alkyl); amido; C 1-6 alkoxycarbonyloxy(C 1-6 alkyl); amino group; N-cyano-S-(C 1-6 -alkyl)sulfonimidoyl, N,S-(di-C 1-6 -alkyl)sulfonimidoyl, aminosulfinyl; C 1-6 -alkylsulfinyl; aminosulfonyl; (di-C 1-6 -alkyl)(oxido)-λ 6 -sulfanylidene-amino, amino(C 1-6 alkyl), or amido(C 1-6 alkyl); any of which groups may be optionally substituted by one or more substituents; R 6 is hydrogen; R 7 is hydrogen or (C 1-6 alkylsulfonyl)amino; X is CR 9 or N; wherein R 9 is hydrogen, halogen or C 1-6 -alkyl substituted by hydroxy; Z is CH or N; and wherein the compound is not 2-(2-fluorophenyl)-1-[ -1-methyl-3,4-dihydro-2 -isoquinolinyl]-1-ethanone. R 1 is hydrogen, halogen, cyano or hydroxy; C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylsulfanyl, C 1-6 alkylsulfinyl, C 1-6 alkylsulfonyl or (C 1-6 -alkylsulfonyl)amino, any of which groups may be substituted by one or more substituents; R 2 is hydrogen, cyano, or halogen; or C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylsulfanyl, C 1-6 alkylsulfinyl, C 1-6 alkylsulfonyl, C 1-6 alkylsulfonylamino, (C 1-6 alkylsulfonyl)amino(C 1-6 alkyl), C 1-6 alkylamido, (C 1-6 alkylacyl)amino, (C 1-6 alkylacyl)amino(C 1-6 alkyl), or heteroaryl, any of which groups may be substituted by one or more substituents; or wherein R 2b is hydrogen or C 1-6 alkylsulfonyl; R 3 is halogen, C 1-6 alkyl, C 1-6 alkoxy or cyano; R 4 is hydrogen, halogen, C 1-6 alkyl, hydroxy, C 1-6 alkoxy, C 1-6 alkylsulfonyl, C 1-6 alkoxycarbonyloxy or C 1-6 alkylaminocarbonyloxy; R 4' is hydrogen, halogen or C 1-6 alkyl; or R 4 and R 4' together form an oxo group; R 5 is hydrogen, cyano or hydroxy; or C 1-6 alkyl; C 1-6- alkylsulfonyl, C 1-6- alkylsulfonylamino; C 1-6- alkylsulfonylamino(C 1-6 alkyl), heterocycle, C 1-6 alkylacylamino(C 1-6 alkyl), C 1-6 alkylureido(C 1-6 alkyl), C 1-6 alkylcarbamate(C 1-6 alkyl); amido; C 1-6 alkoxycarbonyloxy(C 1-6 alkyl); amino group; N-cyano-S-(C 1-6 -alkyl)sulfonimidoyl, N,S-(di-C 1-6 -alkyl)sulfonimidoyl, aminosulfinyl; C 1-6 -alkylsulfinyl; aminosulfonyl; (di-C 1-6 -alkyl)(oxido)-λ 6 -sulfanylidene-amino, amino(C 1-6 alkyl), or amido(C 1-6 alkyl); any of which groups may be optionally substituted by one or more substituents; R 6 is hydrogen; R 7 is hydrogen or (C 1-6 alkylsulfonyl)amino; X is CR 9 or N; wherein R 9 is hydrogen, halogen or C 1-6 -alkyl substituted by hydroxy; Z is CH or N; and wherein the compound is not 2-(2-fluorophenyl)-1-[ -1-methyl-3,4-dihydro-2 -isoquinolinyl]-1-ethanone.