Real-world dostarlimab use in advanced/recurrent endometrial cancer in France.

INTRODUCTION: In October 2020, the French Health Authority granted early access outside of the clinical trial setting for dostarlimab, a programmed death-1 inhibitor. Dostarlimab was approved by the European Medicines Agency (in April 2021) as monotherapy for patients with post-platinum mismatch repair deficient/microsatellite instability-high advanced/recurrent endometrial cancer, based on the results of the GARNET trial (NCT02715284). METHODS: This was a real-world descriptive analysis of patients granted cohort temporary authorization of use to receive dostarlimab between November 2020 and June 2021. Physicians could complete follow-up forms at each treatment cycle to provide clinical information, safety, and efficacy data. Safety and disease progression data were also captured through pharmacovigilance reports. RESULTS: Of 95 temporary authorization of use requests made by 80 oncologists in 59 French hospitals, 87 patients were eligible, and 80 received≥1 dose of dostarlimab. Based on treatment response assessments received (n=43), the mean (standard deviation) time from treatment initiation to response evaluation was 11 (6) weeks. The disease control rate (complete plus partial responses plus stable disease rates) was 56% (n=24/43), and the overall response rate was 35% (n=15/43); both consistent with those reported in the GARNET trial. No new safety signals were reported. DISCUSSION: The enrolment of 80 patients in an 8-month period highlights the need for access to novel treatment regimens in France for these patients post-platinum. Prospective randomized studies are ongoing to assess the efficacy and safety of dostarlimab and other checkpoint inhibitors as first-line treatment in patients with endometrial cancer.