Real-world outcome of dostarlimab in dMMR/MSI-H advanced/recurrent endometrial cancer: Updated results from Korean expanded access program

초록

Background: In Korea, dostarlimab, a programmed death 1 (PD-1) inhibitor, is approved and insured for patients (pts) with mismatch repair deficient/microsatellite instabilityehigh (dMMR/MSI-H) advanced/recurrent endometrial cancer (EC) that has progressed despite platinum-based chemotherapy. Pts across 16 major medical institutions were given dostarlimab in the Korean expanded access program (EAP). We present updated real-world data from these pts. Methods: Pts with advanced/recurrent dMMR/MSI-H EC with 2 lines of prior systemic chemotherapy and no prior anti-PD-(L)1 agent received 500mg of dostarlimab intravenously once every 3 weeks for 4 cycles, then 1000mg once every 6 weeks for 2 years until disease progression or discontinuation due to intolerable toxicity. Tumor response, time to treatment discontinuation (TTD), and adverse events (AEs) were recorded. Results: At data cutoff (31 Jan 2024), 29 pts were treated with dostarlimab. Median (range) age was 56 (40e71) years. Median follow-up was 8.35 months; 25 pts were evaluated for tumor response. Of these, 7 (28%) and 6 (24%) pts had complete and partial responses, respectively; overall response rate was 52%; median TTD was not reached. Treatment-related AEs (TRAEs) were experienced by 10 (34.5%) pts; 2 (6.9%) had grade 3 TRAEs. No pts discontinued due to TRAEs. Serious AEs occurred in 4 (13.8%) pts; none were directly related to treatment. Conclusions: The updated results of the Korean EAP of dostarlimab for pts with advanced/recurrent dMMR/MSI-H EC continued to show promising antitumor activity with no new safety signals. This is the first real-world study of dostarlimab in Asian pts with EC and the results are consistent with the GARNET trial (NCT02715284), further supporting dostarlimab use in Asian pts.