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: wherein Q, V and W independently represent -N= or -C=; B is a divalent radical selected from (B1), (B2), (B3), (B4), (B5) and (B6), 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; -[Linker1]- and [Linker2]-independently represent a bond, or a divalent linker radical; and R is (a) a radical of formula R1R2CHNH-Y-L1-X1-(CH2)Z- or (b) a radical of formula R-L1-Y1-(CH2)Z-.