Retrospective study of advanced melanoma patients treated with ipilimumab after nivolumab: analysis of 60 Japanese patients

Immune checkpoint inhibitors play an important role in the current management of advanced melanoma [1–3]. Ipilimumab, a monoclonal antibody that binds the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) molecule on the surface of T cells and blocks CTLA-4 mediated signaling, was the first checkpoint inhibitor approved for melanoma treatment [1]. However, anti-programmed death-1 (PD-1) monoclonal antibodies (αPD-1mAbs: nivolumab [4,5] and pembrolizumab [6,7]) were shown to be more effective than αCTLA-4mAb, and the current melanoma guideline recommends αPD-1mAbs as the first-line treatment for patients without BRAF mutation (NCCN melanoma guideline, version 1.2017).