Abstract 397P
Background
In Korea, dostarlimab, a programmed death 1 (PD-1) inhibitor, is approved and insured for patients (pts) with mismatch repair deficient/microsatellite instability–high (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 (40–71) 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. Table: 397P
| Korean expanded access program for mismatch repair deficient/microsatellite instability–high advanced/recurrent endometrial cancer | |
| Median follow-up, months | 8.35 |
| Tumor response, n (%) | N=25 |
| Overall response rate | 13 (52) |
| Complete | 7 (28) |
| Partial | 6 (24) |
| Adverse events, n (%) | N=29 |
| Treatment-related adverse event (TRAE) | 10 (34.5) |
| Grade ≥3 TRAE | 2 (6.9) |
| Serious AE (SAE) | 4 (13.8) |
| Treatment-related SAE | 0 |
| Discontinuation due to AE | 0 |
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.
Clinical trial identification
Editorial acknowledgement
Writing and editorial support, funded and coordinated by GSK, was provided by Rebecca Yao, PhD, and Joyce Lee, PhD, CMPPTM, of Nucleus Global, an Inizio company.
Legal entity responsible for the study
GSK.
Funding
GSK.
Disclosure
K. Kim: Financial Interests, Personal, Advisory Board: Noul Inc. M.C. Lim: Financial Interests, Personal and Institutional, Advisory Role: AstraZeneca, Boryung, CKD Pharm, Genexine, Hospicare, GI Innovation, Takeda; Financial Interests, Personal and Institutional, Research Funding: AbbVie, Amgen, Astellas, AstraZeneca, BeiGene, Cellid, CKD Pharm, Clovis, Eisai, Genexine, GSK, Incyte, Merck, MSD, OncoQuest, Pfizer, Roche. M.J. Bae: Financial Interests, Personal, Full or part-time Employment: GSK. All other authors have declared no conflicts of interest.