Exploring the benefit/risk associated with antiangiogenic agents for the treatment of non-small cell lung cancer patients

Abstract

Following the approval of bevacizumab, an antibody targeting VEGF-A, for advanced non-squamous non-small cell lung cancer (NSCLC) in 2006, intensive efforts were put into the clinical development of antiangiogenic agents for NSCLC. Currently, the other antiangiogenic agents approved for NSCLC are ramucirumab, a VEGF receptor-2 (VEGFR-2)-targeting antibody indicated for both squamous and non-squamous NSCLC in the United States, and nintedanib, an anti-VEGFR-1/2/3, platelet-derived growth factor receptor-α/β, fibroblast growth factor receptor-1/2/3 angiokinase inhibitor indicated for adenocarcinoma of the lung in the European Union. Many other antiangiogenic agents are being evaluated in phase III trials for NSCLC, including aflibercept, sunitinib, sorafenib, cediranib, and vandetanib. Although many of the same signaling pathways are targeted by these novel agents, mixed efficacy results have been observed in these trials. Moreover, safety issues have raised concerns about using antiangiogenic agents in this patient population, and fatal bleeding events have been reported. Importantly, although no biomarker has yet been validated for antiangiogenic agents in NSCLC, biomarkers that show potential include circulating levels of short VEGF-A isoforms, expression of neuropilin-1 and VEGFR-1 in tumors and plasma, genetic variants in VEGF-A and VEGFR, and tumor protein p53 mutations (with the latter having been shown to correlate with increased levels of VEGF-A transcripts). This review provides an overview of the clinical benefit and risk associated with the use of antiangiogenic agents for NSCLC, and summarizes the research to date on the identification of predictive biomarkers for antiangiogenic therapies.