Specific destruction of hybridoma cells by antigen-toxin conjugates demonstrate an efficient strategy for targeted drug therapy in leukemias of the B cell lineage.

Many types of leukemia including multiple myeloma remain essentially incurable despite recent developments in immuno- and chemotherapy. The effectiveness of these therapies might be greatly enhanced by targeting cell surface proteins unique to the malignant clone, which for leukemias of the B cell lineage means clonotypic surface immunoglobulin (sIg). As this immunoglobulin (Ig) is necessarily epitope specific, we are developing ligand-toxin conjugates (LTCs) as a strategy for delivering toxins and other drugs to clonotypic tumor cells.