Patent ID: 7833528

Claim:
A method for treating target cells, tissues or pathogens in a subject comprising: a) mixing (i) a multispecific targeting protein comprising at least one target-binding site and one hapten-binding site, and (ii) a hapten-enzyme covalent conjugate comprising two haptens linked by a peptide of from 2 to 10 amino acid residues in length, wherein the hapten-enzyme covalent conjugate is a carboxylesterase-IMP222 (Ac-Cys-Lys(DTPA)-Tyr-Lys(DTPA)-NH2 (SEQ ID NO: 2)); b) forming a non-covalently bound complex between the multispecific targeting protein and the hapten-enzyme covalent conjugate, wherein the non-covalently bound complex is formed prior to administration of the complex to a subject; c) administering the non-covalently bound complex to a subject; and d) administering to the subject a chemotherapeutic drug or prodrug, capable of being converted to a more active drug by the enzyme attached to the non-covalently bound complex.