PDCD1 and metastatic melanoma: Toripalimab, a selective recombinant, humanized monoclonal antibody against PD-1, prevents binding of PD-1 with programmed death ligands 1 and 2.[16] In 2018, toripalimab was approved in China for use in the treatment of unresectable or metastatic melanoma that has failed previous systemic therapy.[16] In a nonrandomized, open-label phase 1b trial, 33 chemotherapy naïve advanced mucosal melanoma patients received toripalimab combined with axitinib, 20 patients achieved an objective response, the confirmed objective response rate was 51.5%, and the disease control rate was 84.4%.