Monoclonal antibody therapy of cancer

Abstract

Monoclonal antibody therapy is beginning to realize its promise. Efficacy has been seen in clinical trials using antibodies that target tumor cell surface antigens such as B-cell idiotypes, CD20 on malignant B cells, CD33 on leukemic blasts, and HER2/neu on breast cancer. Unconjugated immunoglobulins directed against CD20 induce partial and complete responses in up to 50% of patients with advanced, indolent non-Hodgkin's lymphoma. When such antibodies are conjugated to radionuclides, complete and overall response rates increase. Conjugates composed of anti-CD33 antibodies and the chemotherapy agent, calicheamicin, show promising activity in patients with relapsed or refractory acute myelogenous leukemia Treatment of patients with advanced breast cancer using the anti-HER2/neu antibody, trastuzumab (Herceptin; Genentech, San Francisco, CA) leads to objective responses in some patients with overexpression of the HER2/neu oncoprotein. These exciting results provide a basis for further refinement of the existing approaches to develop new antibody-based cancer therapy strategies.