Targeted therapy of advanced non-small cell lung cancer: the role of bevacizumab

Lung cancer is the leading cause of cancer death in the United States. The majority of patients present with advanced stage disease, and treatment with standard cytotoxic chemotherapy agents have been shown to provide a modest improvement in survival, reduce disease-related symptoms, and improve quality of life. However, with standard chemotherapy treatments the prognosis is poor with the majority of patients dying in less than a year from diagnosis. Treatment with standard chemotherapy agents has reached a therapeutic plateau, and recent investigations have focused on therapies that target a specific pathway within the malignant cell or related to angiogenesis. The most promising of the targeted therapies are agents that target the process of angiogenesis. Bevacizuamab is a monoclonal antibody that binds to circulating vascular endothelial growth factor (VEGF)-A, and prevents binding of VEGF to vascular endothelial growth factor receptors, thus inhibiting activation of the VEGF pathway and angiogenesis. A recent phase III trial of first-line treatment of advanced non-small cell lung cancer revealed a statistically significant improvement in response, progression-free survival, and overall survival with the combination of bevacizumab and standard chemotherapy in comparison to standard chemotherapy alone. Bevacizumab is the only targeted therapy that has been shown to improve survival when combined with standard chemotherapy in the first-line setting.