Anti-Growth Factor Receptor Antibodies as Therapy for Cancer

The idea of attacking cancer cells at the cell surface was revived in the past decade by the availability of monospecific heteroantisera. Phase I trials using monoclonal antibodies to most tumor cell antigens have shown little anti-tumor activity (Reviewed in 1,2). The reasons for these failures are complex, but include heterogeneity of tumor antigen expression; antibodyinduced antigen modulation from the cell surface; formation of human anti-mouse antibodies; and the uncertain efficacy of the host cell anti-tumor response (1,2). Immunoconjugates employing monoclonal antibodies as carriers for toxins, drugs, or radioisotopes and chimeric human-mouse monoclonal antibodies remain under investigation (1,2).