Single-drug checkpoint inhibition has emerged to be an efficacious treatment in patients with recurrent malignant pleural mesothelioma (MPM). This study aims to assess the efficacy and safety of the combination therapy of ipilimumab and nivolumab in patients with previously treated and relapsed MPM.

This single-arm, prospective, single-center, phase 2 trial included a total of 38 patients with MPM with progression after one line of platinum chemotherapy. The patients were assigned to receive intravenous nivolumab plus intravenous ipilimumab every 6 weeks up to 4 times. The primary objective of the study was disease control at 12 weeks.

Of 38 patients initially included, 34 were evaluable for response assessment at 12 weeks. Of these 34 patients, 10 (29%) had a partial response, and 13 (38%) had stable disease. Therefore, 23 patients (68%) achieved disease control. The rate of treatment-related adverse events was 94% (33 patients), with the most commonly occurring events being skin disorders, fatigue, and infusion-related reactions. Grade 3 treatment-related adverse events occurred in 34% (12) of the patients.

The research concluded that in patients with recurrent malignant pleural mesothelioma, the combination of ipilimumab and nivolumab showed efficacious results and a consistent safety profile. However, the sample size of the study was small, and a large-scale trial is required.