Real-world safety of nivolumab in patients with malignant pleural mesothelioma in Japan: post-marketing surveillance study

Objective This post-marketing surveillance (PMS) was conducted to evaluate the incidence of adverse events with nivolumab in patients with unresectable, advanced or recurrent malignant pleural mesothelioma (MPM) that had progressed after first-line chemotherapy and to identify factors that potentially affected its safety in real-world clinical practice.Methods Patients who had not received nivolumab previously were registered between November 2018 and February 2021. Nivolumab was given intravenously 240 mg every 2 weeks or 480 mg every 4 weeks. Patients were followed up for 6 months after treatment initiation. Information on patient characteristics, treatment status, and adverse events was collected.Results This PMS enrolled 124 patients, involving 48 sites across Japan. At 6 months, nivolumab therapy was ongoing in 35.5% of patients (44/124) and had been discontinued in 64.5% (80/124). The overall incidence of treatment-related adverse events (TRAEs) was 40.3%; the incidence of Grade 3 or higher TRAEs was 12.9%. The pattern of TRAEs based on System Organ Class categories was generally consistent with those seen in the Japanese phase II MERIT study. The most common Grade 3 or higher TRAEs were interstitial lung disease (2.4%), lung disorder, and diarrhea (each 1.6%). The incidence of TRAEs was significantly higher in inpatients or patients who had good PS, high bodyweight, high body mass index, or autoimmune diseases than in those without these characteristics.Conclusion The post-marketing incidence of TRAEs with nivolumab in patients with MPM has been evaluated, and no new safety signals were identified compared to the phase II clinical trial in Japan. In this post-marketing surveillance study of nivolumab in patients with malignant pleural mesothelioma in Japan, no new safety signals were identified compared with phase II clinical trial data.