Nivolumab for the treatment of unresectable pleural mesothelioma

Introduction: Platinum-based chemotherapy is the current first-line standard therapy for unresectable malignant pleural mesothelioma (MPM). Recently, immune-checkpoint inhibitors (ICI) have been intensively investigated as treatment options for this disease. Nivolumab, an anti-programmed cell death (PD)-1 agent, was one of the first drugs used and is representative of available ICIs. Areas covered: This review discusses previous relevant reports and current ongoing trials of nivolumab. The efficacy and safety of nivolumab have been investigated mostly in second-line or later treatment settings as both monotherapy and in combination with other ICIs. Particularly, nivolumab monotherapy yielded promising efficacy with an objective response rate of 29% and median overall survival of 17.3 months in salvage settings in the single-arm, Japanese phase 2 trial (MERIT). Notably, the study led to Japanese approval of nivolumab for unresectable recurrent MPM. Several trials with monotherapy or cotherapy with nivolumab have commenced, including randomized trials of nivolumab monotherapy vs. placebo in the salvage setting, and cotherapy with nivolumab and ipilimumab vs. the platinum doublet in the frontline setting. Expert opinion: Nivolumab seems like a reasonable option for unresectable, relapsed MPM despite the lack of randomized trial data. Ongoing pivotal trials will confirm its efficacy.