Strategies targeting angiogenesis in advanced non-small cell lung cancer

Tumor angiogenesis is a frequent event in the development and progression of non-small cell lung cancer (NSCLC) and has been identified as a promising therapeutic target. The vascular endothelial growth factor (VEGF) family and other angiogenic factors, including fibroblast growth factor and platelet-derived growth factor, promote the growth of newly formed vessels from preexisting vessels and change the tumor microenvironment. To date, two antiangiogenic monoclonal antibodies, bevacizumab and ramucirumab, which target VEGF-A and its receptor VEGF receptor-2, respectively, have been approved for the treatment of locally advanced or metastatic NSCLC when added to first-line standard chemotherapy. Numerous oral multitargeting angiogenic small molecule tyrosine kinase inhibitors (TKIs) have been widely evaluated in advanced NSCLC, but only nintedanib in combination with platinum-based doublet chemotherapy has demonstrated a survival benefit in the second-line setting. Additionally, small-molecule TKIs remain the standard of care for patients with mutated EGFR, ALK or ROS1. Moreover, immune checkpoint inhibitors that target the programmed cell death protein 1 (PD-1) and programmed cell death protein ligand 1 (PD-L1) are changing the current strategy in the treatment of advanced NSCLC without driver gene mutations. The potential synergistic activity of antiangiogenic agents and TKIs or immunotherapy is an interesting topic of research. This review will summarize the novel antiangiogenic agents, antiangiogenic monotherapy, as well as potential combination therapeutic strategies for the clinical management of advanced NSCLC.

Anti-angiogenesis in Personalized Therapy of Lung Cancer

Upregulation of angiogenesis is a frequent occurrence in lung cancer and is reported to represent a negative prognostic factor. This provides a rationale for the development and evaluation of anti-angiogenic agents. To date bevacizumab, a monoclonal antibody directed against serum VEGF, is the only anti-angiogenic agent that has demonstrated improved overall survival for patients with lung cancer. Meta-analysis of trials of bevacizumab in combination with platinum-based chemotherapy for NSCLC, show a 10% reduction in the risk of death (HR 0.90, 95% CI 0.81-0.99). However, therapy with bevacizumab is limited to NSCLC patients with non-squamous histology, good performance status, no brain metastases and the absence of bleeding or thrombotic disorders. More recently, similar survival was observed in a non bevacizumab containing regimen of carboplatin, pemetrexed and maintenance pemetrexed. Multiple oral anti-angiogenic compounds have been evaluated in NSCLC, both in first-line therapy, or upon disease progression. The majority of agents have shown some evidence of activity, but none have clearly demonstrated improvements in overall survival. Increased toxicities have been observed, including an increased risk of death for some agents, limiting their development. Promising data exist for sunitinib in patients with heavily pre-treated NSCLC, and nintedanib in combination with docetaxel, as second-line therapy for NSCLC. However, these findings require validation. Currently, there is no established role for anti-angiogenic therapy in SCLC, although there is some promise for sunitinib as maintenance therapy following platinum and etoposide chemotherapy. The challenge for anti-angiogenic therapy is to understand whether treatment effects in a subpopulation, are lost among a larger unselected population of patients. There is a need for additional translational research to identify predictive biomarkers for anti-angiogenic therapy.