Results of clinical trials with anti-programmed death 1/programmed death ligand 1 inhibitors in lung cancer.

One of the main hallmarks of cancer is the capability of evading immune destruction. In order to drive tumor progression, malignant cells are able to promote immunosuppressive mechanisms avoiding recognition and elimination. Increasing knowledge of the mechanisms of immune tolerance has led to the identification of several membrane receptors strongly implicated in this cancer feature: the immune checkpoints. Among them, programmed death 1 (PD-1) receptors and their ligands have been identified as potential targets for a new anti-cancer therapeutic approach: the use of immune-modulatory monoclonal antibodies designed to interrupt the immune escape activated by the interaction of PD-1 receptors and their ligands. Five of these antibodies are now in their late stages of clinical development and this review will summarize their up-to-date efficacy and toxicity data.