Combined Checkpoint Inhibition and Chemotherapy: New Era of 1st-Line Treatment for Non-Small-Cell Lung Cancer

Platinum-based chemotherapy has long been the first-line treatment of choice for metastatic non-small-cell lung cancer (NSCLC) patients who lack targetable gene mutations. The arrival of checkpoint blockade has led to a vast shift in the treatment landscape of NSCLC. Among NSCLC patients with PD-L1 expression in ≥50% of tumor cells, treatment with pembrolizumab leads to a superior progression-free and overall survival compared to platinum-doublet chemotherapy in the first-line setting. Furthermore, the addition of pembrolizumab to standard chemotherapy of pemetrexed and a platinum-based drug resulted in significant longer progression-free survival and overall survival irrespective to PD-L1 expression. In this review, we focus on the molecular rationale for the combination therapy and the results of completed clinical studies.