Immune checkpoint inhibitors in the treatment of pleural mesothelioma: insights from real-world data

Background Immune checkpoint inhibitors (ICIs) have recently emerged as a promising strategy for the treatment of pleural mesothelioma (PM). Methods This retrospective study evaluated treatment efficacy and safety in Japanese patients with PM treated with nivolumab and ipilimumab (N + I group: 41 patients) as first-line therapy and nivolumab monotherapy (N group: 33 patients) as second- or later-line treatment. Results The median overall survival (OS) and progression-free survival (PFS) were not reached and 10.4 months in the N + I group, and 8.6 months and 3.5 months in the N group, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 68.3% of the N + I group and 72.7% of the N group, with grade 3-4 TRAEs in 19.5% and 12.1% of patients, respectively. Patients with an ECOG PS 0-1 had significantly better OS and PFS in both treatment groups (p < 0.001). In the N + I group, OS was significantly better in patients with TRAEs (p = 0.020) and in those with the epithelioid subtype (p = 0.047), although PFS was not significantly different (p = 0.138 and p = 0.154, respectively). In the N group, both OS (p = 0.007) and PFS (p = 0.048) were significantly longer in patients with TRAEs. Conclusion This study provides valuable real-world clinical evidence of the efficacy and safety of nivolumab plus ipilimumab and nivolumab monotherapy in Japanese patients with PM. These results support the use of ICIs as a viable treatment option for advanced or relapsed disease.