Melanomas are highly immunogenic tumors that evade the immune system by exploiting innate checkpoint pathways, rendering effector T-cells anergic. The immunotherapeutic approach of checkpoint inhibition can restore and invigorate endogenous antitumor T-cell responses and has become an important treatment option for patients with advanced melanoma. The CTLA-4 inhibitor ipilimumab and the PD-1 inhibitors nivolumab and pembrolizumab have been shown to induce durable responses and improve overall survival in metastatic, refractory melanoma. Optimization and validation of pretreatment biomarkers to predict response to these agents is a crucial area of ongoing research. Combination immunotherapy has recently demonstrated superior response rates compared to monotherapy; further investigation is needed to refine combinatorial strategies.
Keywords: PD-1; immune checkpoint inhibitors; melanoma; nivolumab.