Immunotherapy in treatment naïve advanced non-small cell lung cancer.

Lung cancer is the leading cause of cancer-related mortality worldwide. Non-small cell lung cancer (NSCLC) comprises approximately 85% of lung cancers and, unfortunately, more than half of these patients are diagnosed with metastatic disease. Platinum-based chemotherapy has for long been the standard frontline therapy for advanced disease. Despite remarkable advances in targeted therapy for a subset of patients harboring a driver mutation, the prognosis in the majority of the lung cancer population have not changed significantly. More recently, immunotherapy has drastically changed the treatment of NSCLC and have established a new treatment paradigm for these patients. Pembrolizumab is now the new mainstay first-line treatment for those with high-PD-L1 expression. However, many questions remain regarding how to sequence and combine these agents in the frontline setting. The optimal patient selection strategies are also unclear. High PD-L1 expression is associated with higher response rates, but even patients with low or absent PD-L1 expression benefit from these drugs. More recently, tumor mutational burden is been proposed as a potential predictive marker for response. This article will review the data regarding the usage of immunotherapy in treatment naive advanced NSCLC.