Epitope/Peptide-Based Monoclonal Antibodies for Immunotherapy of Ovarian Cancer

Two monoclonal antibodies, RP215 and GHR106, were selected, respectively, for the research and development of anti-cancer drugs targeting ovarian cancer and other types of human cancer. RP215 was shown to react with a carbohydrate-associated epitope located mainly in the variable regions of immunoglobulin heavy chains expressed on the surface of almost all cancer cells in humans. GHR106 was generated against a synthetic peptide corresponding to N1-29 amino acid residues in the extracellular domains of human GnRH receptor, which is surface-expressed by most cancer cells as well as the anterior pituitary. This monoclonal antibody was shown to serve as a bioequivalent analog to GnRH-derived decapeptides currently used clinically. The molecular mechanisms of action of these two antibody-based anti-cancer drug candidates were well elucidated following numerous biochemical, immunological, and molecular biological studies, mainly by using ovarian cancer as the model. Further preclinical studies with humanized forms of these two antibodies are essential.