Bevacizumab (Avastin; Genentech, Inc.; South San Francisco, CA) is a recombinant, humanized monoclonal antibody to vascular endothelial growth factor, a key regulator of tumor angiogenesis. Bevacizumab demonstrated potent antitumor activity in preclinical models and has also shown biologic activity and clinical benefit in clinical studies. Notably, a randomized, placebo-controlled phase II trial in renal cell carcinoma demonstrated a significantly longer time to tumor progression with bevacizumab monotherapy. Furthermore, in a phase III trial for untreated advanced colorectal cancer, the addition of bevacizumab to chemotherapy led to significantly longer overall survival and progression-free survival times than chemotherapy alone. The clinical development of bevacizumab has been expanded to include confirmatory phase III trials and exploratory phase II trials in a variety of solid tumors and hematologic malignancies. Treatment regimens being examined include bevacizumab alone and in combination with conventional chemotherapy, radiation, immune therapy, and biologically targeted agents.