Programmed cell death receptor-1 (PD-1) and programmed cell death-1 ligand-1 (PD-L1) represent promising novel targets in immunotherapy. PD-1 is an inhibitory receptor involved in T-cell regulation that is expressed by activated T cells. Nivolumab and pembrolizumab are anti-PD-1 antibodies that have shown antitumor activity and acceptable tolerability in patients with metastatic melanoma in preclinical development and Phase I/II clinical trials. Several ongoing Phase III studies are further investigating the efficacy and safety of anti-PD-1 therapy in melanoma. Initial data on the combination of anti-PD-1 and anti-cytotoxic T-lymphocyte-associated antigen 4 blockade with nivolumab and ipilimumab also appear promising. Monoclonal antibodies to blockade PD-L1 may also be an effective immunotherapy strategy in melanoma and several anti-PD-L1 antibodies are in development.
Keywords: MK3475; anti-PD-1; anti-PD-L1; immunotherapy; metastatic melanoma; nivolumab.