Combination Strategies on the Basis of Immune Checkpoint Inhibitors in Non-Small-Cell Lung Cancer: Where Do We Stand?

The era of immune checkpoint inhibitors, especially programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) antibodies in the treatment of advanced non-small-cell lung cancer (NSCLC) is coming. Because of the lack of the definite biomarkers to select the optimal responders, only approximately 20% of patients with advanced NSCLC would respond to single checkpoint inhibitors-based immunotherapy. Moreover, primary or acquired resistance to conventional therapies is inevitable in most cases. Thus, combinations are pushed to move forward to be an alternative strategy and surely, it would be a future direction. Combination approaches on the basis of PD-1/PD-L1 inhibitors are currently designed to re-energize the immune system with complementary/synergetic mechanisms and could achieve durable antineoplastic effects in NSCLC. Herein, we highlight the potential combinations on the basis of PD-1/PD-L1 inhibitors in NSCLC, with other immunotherapies, chemotherapy, radiotherapy, and targeted therapy in this current review.