Abstract: Activated cytotoxic compounds are described for attachment to targeting molecules for the treatment of a mammalian disease condition which comprise, an activator, a spacer linker, a linker (e.g., self-immolative), and a cytotoxic drug selected from the group consisting of AMINO-SUBSTITUTED (E)-2,6-DIALKOXYSTYRYL 4-SUBSTITUTED BENZYLSULFONES, AMINO-AND-HYDROXY SUBSTITUTED STYRYLSULFONANILIDES, and SUBSTITUTED PHENOXY- AND PHENYLTHIO-STYRYLSULFONE DERIVATIVES. Activated cytotoxic compound attached to a targeting molecule are described wherein the targeting molecule is selected from the group consisting essentially of an antibody, a receptor, a ligand, a cytokine, a hormone, and a signal transduction molecule. The invention is further directed to a method of treatment of disease conditions.