Real-World Immunotherapy Outcomes in Unresectable Peritoneal Mesothelioma: A French Experience
Menée en France dans un contexte de vie réelle à partir de données portant sur 22 patients atteints d'un mésothéliome péritonéal non résécable traité entre 2017 et 2024 (âge médian au diagnostic : 57 ans ; durée médiane de suivi : 13,7 mois), cette étude analyse l'efficacité, du point de vue de la survie sans progression et de la survie globale, de stratégies thérapeutiques à base d'immunothérapies (avec ou sans agent antiangiogénique)
Background: Peritoneal mesothelioma is a rare disease treated with curative approach- cytoreductive surgery and hyperthermic intraperitoneal chemotherapy -when resectable.In case of inoperable disease or extra-peritoneal involvement, the standard of care is based primarily on systemic chemotherapy. Platinum-based chemotherapy is used in the first-line setting, but no standard exists for subsequent lines.Peritoneal mesothelioma harbors a pro-inflammatory tumor microenvironment, making it potentially sensitive to immune checkpoint inhibitors (ICIs).
Patients and Methods: We included inoperable patients with peritoneal mesothelioma treated between 2017 and 2024 at two institutions in France, using ICIs-based treatments (immunotherapy with or without anti-angiogenic agents).The primary endpoints were progression-free survival (PFS) and overall survival (OS).
Results: A total of 22 patients with peritoneal mesothelioma were included.The median age at diagnosis was 57 years (IQR: 50–66);the majority had epithelioid histology (n=17; 77%).After a median follow-up of 13.76 months (95% CI: 6.40–22.49),median Progression free survival(PFS) was 10.22 months (95% CI: 4.82–15.87),median Overall Survival(OS) was 16.8 months (95% CI: 6.46–37.73) No significant differences in PFS (p=0.73) or OS (p=0.16) were observed between BAP1-positive and BAP1-negative tumors.Among evaluable patients (n=13, 62%), the objective response rate was 30% (95% CI: 22%–50%).The disease control rate at 6 and 12 months for the entire cohort was:55% (95% CI: 33%–74.5%) at 6 months and 41% (95% CI: 21.9%–63.04%) at 12 months.Grade 3 toxicity occurred in 3 patients; no grade 4 toxicity was reported.
Conclusion: The benefit of ICI-based treatment was confirmed in this European real-world cohort and should be considered as a treatment option in this rare setting.
European Journal of Cancer , résumé, 2025