Based on preclinical experiments conducted in our laboratories, we hypothesize that the aggressive behavior of HER2-overexpressing breast cancers is due in part to increased angiogenesis resulting from HER2-induced increases in vascular endothelial growth factor (VEGF) expression. In vivo experiments suggest that combined blockade of the HER2 receptor and VEGF results in superior anti-tumor efficacy compared with either treatment alone.
The current clinical trial, for which the phase I portion has been completed, will examine the efficacy and safety of trastuzumab (Herceptin) and bevacizumab (anti-VEGF antibody) in the treatment of HER2-overexpressing metastatic breast cancer.
