Immune Checkpoint Inhibition in Lung Cancer

Lung cancer is the leading cause of cancer deaths both in the United States and worldwide with estimates by the American Cancer Society for the year 2016 and GLOBOCAN for the year 2012 of 158,000 and 1.6 million deaths, respectively. Among patients with lung cancer, approximately 87% of patients have a broad group of histologies called non-small cell carcinoma (NSCLC), whereas approximately 13% have small cell lung cancer (SCLC). NSCLC may be further subdivided into adenocarcinoma (ADC), squamous cell carcinoma (SQCC), and large cell carcinoma (LC). Most patients with NSCLC present with advanced stage, which is essentially incurable and treated with palliative intent. With the exception of selected patients with activating EGFR mutations or ALK translocations, for which targeted therapy with small molecule tyrosine kinase inhibitors is associated with a prolonged clinical benefit, the standard of care for most patients with metastatic NSCLC is a platinum-based chemotherapy doublet. Monoclonal antibodies against either the vascular endothelium growth factor (VEGF) or epidermal growth factor receptor (EGFR) have been approved based on a modest benefit over chemotherapy alone and are commonly used in the absence of contraindications.