Bevacizumab and erlotinib: a promising new approach to the treatment of advanced NSCLC.

Biologic agents that target molecules involved in tumor growth, progression, and pathological angiogenesis--such as the human epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF)--have demonstrated efficacy in patients with non-small cell lung cancer (NSCLC). Erlotinib (Tarceva); OSI Pharmaceuticals, Inc., Melville, NY, Genentech, Inc., South San Francisco, CA, and F. Hoffmann-La Roche Ltd, Basel, Switzerland), a highly selective tyrosine kinase inhibitor that inhibits EGFR, and bevacizumab (Avastin); Genentech, Inc., South San Francisco, CA, and F. Hoffmann-La Roche Ltd, Basel, Switzerland), a VEGF-targeted recombinant humanized monoclonal antibody, have displayed very encouraging activity in a randomized phase II trial in patients with previously treated NSCLC. Because erlotinib and bevacizumab act on two different pathways critical to tumor growth and dissemination, administering these drugs concomitantly may confer additional clinical benefits to cancer patients with advanced disease, by virtue of their complementary (or additive) antitumor activity. The combination of bevacizumab plus erlotinib may prove to be a viable second-line alternative to chemotherapy or erlotinib monotherapy in patients with NSCLC. The benefits of the combination may be further enhanced by selecting for patients who are likely to respond to this therapy. While a number of potential predictive markers have been identified for erlotinib, their value remains to be confirmed in prospective trials. In addition, the application of such personalized therapy will also depend on the availability of validated screening methods.