Update on angiogenesis inhibitors

Purpose of review: A number of therapeutic agents have been developed which have anti-angiogenic potential. Here we present the most recent data from clinical trials with some of the promising inhibitors of angiogenesis. Recent findings: Agents that target the vascular endothelial growth factor signaling pathway are the furthest along in clinical development. The last year has brought US Food and Drug Administration approval of bevacizumab (Avastin), a recombinant humanized anti-vascular endothelial growth factor monoclonal antibody. Bevacizumab has demonstrated a survival advantage in combination with chemotherapy for patients with metastatic colorectal cancer. Other agents with early promising results include PTK787/ZK 222584 (Vatalanib), ZD6474, and BAY 43-9006 (Sorafenib). Summary: Angiogenesis inhibitors show promise, but evaluation for optimal efficacy has been a problem, given that the mechanisms of action of these agents differ from conventional cytotoxic agents and surrogate markers for inhibition of angiogenesis are not available.