Background: In the phase 3 CheckMate 743 study (NCT02899299), first-line nivolumab plus ipilimumab significantly improved overall survival (OS) versus chemotherapy in patients with unresectable malignant pleural mesothelioma [(unresectable MPM)]. We report updated data with 3-year minimum follow-up.
Patients and methods: Adults with previously untreated, histologically confirmed, unresectable MPM and Eastern Cooperative Oncology Group performance status of ≤1 were randomized 1:1 to nivolumab (3 mg/kg every 2 weeks) plus ipilimumab (1 mg/kg every 6 weeks) for up to 2 years, or 6 cycles of platinum plus pemetrexed chemotherapy. This report includes updated efficacy and safety outcomes, exploratory biomarker analyses including 4-gene inflammatory expression signature score, and a post hoc efficacy analysis in patients who discontinued treatment due to treatment-related adverse events (TRAEs).
Results: With median follow-up of 43.1 months, nivolumab plus ipilimumab continued to prolong OS versus chemotherapy. Median OS was 18.1 versus 14.1 months (HR [95% CI], 0.73 [0.61–0.87]), and 3-year OS rates were 23% versus 15%, respectively. Three-year progression-free survival rates were 14% versus 1%, and objective response rates were 40% versus 44%. At 3 years, 28% versus 0% of responders had an ongoing response. Improved survival benefit with nivolumab plus ipilimumab versus chemotherapy was observed across subgroups, including histology. A high score of the 4-gene inflammatory signature appeared to correlate with improved survival benefit with nivolumab plus ipilimumab. No new safety signals were observed with nivolumab plus ipilimumab, despite patients being off therapy for one year. In patients who discontinued nivolumab plus ipilimumab due to TRAEs, median OS was 25.4 months, and 34% of responders maintained their responses for ≥3 years after discontinuation.
Conclusions: With 3 years’ minimum follow-up, nivolumab plus ipilimumab continued to provide long-term survival benefit over chemotherapy and a manageable safety profile, supporting the regimen as standard-of-care treatment for unresectable MPM, regardless of histology.
Asbestos-Mesothelioma Case Evaluation
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