Compounds of formula: (I), and salts, N-oxides, hydrates and solvates thereof are histone deacetylase inhibitors and are useful in the treatment of cell proliferative diseases, including cancers: (I) wherein Q, V and W independently represent -N= or -C=; B is a divalent radical selected from: (IIA), (IIB), (IIC), (IID), and (IIE). Wherein the bond marked * is linked to the ring containing Q, V and W through -[Linker1]- and the bond marked ** is linked to A through -[Linker2]-; A is an optionally substituted mono-, bi- or tri-cyclic carbocyclic or heterocyclic ring system; and -[Linker1]- and -[Linker2]- independently represent a bond, or a divalent linker radical.