Immune checkpoint inhibitors in lung cancer: past, present and future.

Inhibitory ligands on tumor cells and their corresponding receptors on T cells are collectively called immune checkpoint molecules and have emerged as druggable targets that harness endogenous immunity to fight cancer. Immune checkpoint inhibitors targeting CTLA-4, PD-1 and PD-L1 have been developed for the treatment of patients with non-small-cell lung cancer and other malignancies, with impressive clinical activity, durable responses and a favorable toxicity profile. This article reviews the development, current status and future directions for some of these agents. The efficacy and safety data for drugs such as ipilimumab, nivolumab, pembrolizumab, atezolizumab and durvalumab are reviewed, along with combination strategies and response evaluation criteria. The toxicity profiles and predictive biomarkers of response are also discussed.