Current evidence and future perspectives of immune-checkpoint inhibitors in unresectable malignant pleural mesothelioma.

Platinum-based chemotherapy is commonly used as the standard first-line treatment for unresectable malignant pleural mesothelioma (MPM). However, in recent times, immune-checkpoint inhibitors (ICIs) have led to a paradigm shift. Herein, we review relevant literature and ongoing trials of ICIs used as both first-line and salvage therapies. Specifically, in the Japanese single-arm, phase II trial, the MERIT trial, nivolumab, an antiprogrammed cell death 1 (PD-1) antibody showed favorable efficacy when used as a salvage therapy. Currently, multiple ICI monotherapy or combination therapy trials have been conducted, which could provide further evidence. Among available ICIs, the anti-PD-1 antibody is promising for unresectable MPM, despite the limited efficacy of anti-CTLA4 monotherapy. Ongoing studies will further confirm the potential efficacy of ICIs for MPM, as observed across other malignancies. It is also crucial to identify any clinically useful predictive biomarkers that could reveal ICIs with maximal effects in MPM.