A compound of formula (I) or a pharmaceutically acceptable salt or solvate or physiologically hydrolysable, solubilizing or immobilizable derivative thereof wherein: any one or two of X., X2 and X3 is a N atom and the remaining two or one of X1, X2 and X3 are independently CR13 Y is selected from SO2 and SO R1, R2, R3, and R7 and the one or two R13 groups are each independently selected from H and R10, R10 is selected from R8, alkyl, aryl, heteroaryl and combinations of two or more thereof and combinations with one or more R9, or R10 is one or more moieties R11 Sinking one or more alkyl, alkoxy, aryl, heteroaryl or R8 or R9 groups or combinations thereof, directly or via a moiety selected from alkylene, arylene, heteroarylene or combinations thereof, wherein alkyl, aryl, heteroaryl groups or moieties thereof may be substituted with one or more groups R12, or R10 is selected from a group R12 R11 is selected from 0-, N—, NH—, N═C, CO—, C00-, CON—, CONH—, S02-, S02N—, S02NH— R12 is selected from halogen, NH2, N02, CN, OH, COOH, CONH2, C(═NH)NH2, S03H, S02NH2, S02CH3, OCH3, OCH2CH3, CF3 R8 and R9 comprise one or more solubilizing moieties independently chosen from i) neutral hydrophilic groups, ii) ionisable organic acids, iii) ionisable organic bases, iv} chemical functions or moieties providing covalent or non-covalent attachment or binding to a solid phase or an immobile receptor and combinations thereof R4, R5 and R6 are each independently selected from H and R10, or two of R4 to R6 are linked to form a cyclic ether or amine containing one or more additional oxygen or nitrogen atoms. The compound may be used for treating a condition mediated by one or more enzymes selected from AKT, Aurora kinase, BCR-ABL, CDK, FLT, GSK3, IKK, JAK, MAPK, PDGF, PI3K, PKA, PKB, PKC, PLK, Src and VEGF family enzymes, or for treating cancer or other proliferative disorder, or for inhibiting growth of cancer cells, or for inducing apoptosis of cancer cells, in a human or animal subject.