Immune checkpoint inhibitors in non-small-cell lung cancer: current status and future directions.

Since 2015, immunotherapies, especially immune checkpoint inhibitors (ICIs), have made great breakthroughs in non-small-cell lung cancer (NSCLC). Among them, nivolumab, pembrolizumab and atezolizumab have been granted US Food and Drug Administration approval for NSCLC. It is imperative to combine ICIs with chemotherapy, radiotherapy, antivascular therapy and targeted therapy. But in the bright future, there are two problems. One is how to use biomarkers to select the beneficiaries. The other is how to achieve a balance between drug effectiveness and safety. There are now seven drugs targeting the programmed death-1/programmed death ligand-1 (PD-1/PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) pathways that have been or are expected to enter clinical treatment. This review focuses on these drugs and summarizes clinical trials that have been reported or that ongoing ones have already entered the recruiting state.