Lung cancer is the first most common malignancy in the wild word, and the leading cause of cancer-related mortality. Approximately 85% of lung cancers are non-small-cell lung cancer (NSCLC). More than half of all lung cancers in the United States are diagnosed at advanced or metastatic stage, which has a 5-year survival of 4.8%. The recommendations for systemic treatment of metastatic NSCLC (stage IV) are guided by patient performance status (PS), tumor histology, and status of tumor biomarkers. Firstline (1L) treatment with platinum-based chemotherapy has long been the standard of care. In the second-line (2L) setting after 1L chemotherapy, the efficacy and safety of antiePD-L1 therapies have been shown in several phase III clinical trials.