The role of anti-epidermal growth factor receptor and anti-vascular endothelial growth factor therapies in the treatment of non-small-cell lung cancer

Abstract

Standard first-line therapy for non-small-cell lung cancer (NSCLC) with platinum-based agents, given in combination with cytotoxic compounds, has reached a relative plateau in its therapeutic efficacy. Novel molecular targeted agents acting on specific pathways have emerged as effective agents for treating NSCLC; some have already produced positive results in phase III trials. Notably, inhibition of the vascular endothelial growth factor (VEGF) pathway with an anti-VEGF antibody, bevacizumab, and targeting the epidermal growth factor receptor (EGFR) pathway with a small-molecule EGFR tyrosine kinase inhibitor erlotinib or a monoclonal antibody (cetuximab) have demonstrated prolonged survival in patients with advanced disease in both the first- and second-line settings. The heterogeneity of signaling processes leading to tumor cell survival and proliferation supports the targeting of multiple signaling pathways as an effective anticancer treatment strategy. Consequently, rational combinations of molecular targeted agents might offer superior clinical efficacy and an alternative treatment option to patients refractory to, or unable to tolerate, standard chemotherapy. The challenge lies in determining which molecular entities should be pursued and the best approach to combine them. This review discusses the potential clinical utility of combining bevacizumab and erlotinib to inhibit both angiogenesis and EGFR signaling as a valid nonchemotherapeutic approach for the treatment of NSCLC. Other combinations of novel therapies that block EGFR and angiogenic pathways, as well as complementary signaling pathways, with unique modes of action and low toxicity profiles could offer an increased repertoire of individualized treatment options for patients with advanced NSCLC.