ABSTRACT
The therapeutic efficacy of cytotoxic antibody conjugates not only depends on the targeting potential of the antibody, but also on the properties of the antigen towards which the antibody is directed. The monoclonal antibody technique allows the production of large amounts of uniform antibodies with defined tumor cell specificity. With the reduction of the toxicity of the free drug at least one of the major aims of targeted cytotoxicity has been achieved. The key to making antibody-drug and antibody-toxin conjugates useful for cancer therapy is to eliminate unwanted functions of the components without adverse effect on other useful properties. The failure of antibodies and cytotoxic antibody conjugates to efficiently localize to tumors in patients is mainly due to their rapid uptake by cells of the reticuloendothelial tissue, and to their immunogenicity which leads to the formation of immune complexes and precludes their repeated administration.
