Dr Lantsman on the Real-World Safety and Efficacy of Dostarlimab Plus Chemo in Endometrial Cancer

“At our institution, we give radiation to these patients, which differs from what we saw in RUBY, where radiation was not given. Interestingly enough, none of these patients at time of analysis had disease progression or recurrence.”

Taliya Lantsman, MD, a hematology/oncology fellow at Beth Israel Deaconess Medical Center, discusses the safety and efficacy of dostarlimab-gxly (Jemperli) plus chemotherapy in patients with advanced endometrial cancer according to findings from a real-world, retrospective, single-institution analysis.

The analysis enrolled 27 patients with stage III, IV, or recurrent endometrial cancer and a variety of histologies, Lantsman began. At the time of treatment initiation with dostarlimab, 56% of patients had stage IV disease, 22% had recurrent disease, and 22% had stage III disease, including stage IIIA (4%), IIIC1 (11%), and IIIC2 (7%). The cohort comprised patients with endometrioid (37%) and serous (26%) histologies, along with carcinosarcoma (11%) and other subtypes (27%).

Results from this analysis presented at the 2025 SGO Annual Meeting on Women’s Cancer showed that the combination regimen demonstrated comparable progression-free survival (PFS) outcomes to those observed in the phase 3 RUBY trial (NCT03981796), Lantsman reported. Patients with mismatch repair–deficient tumors experienced improved PFS relative to those with mismatch repair–proficient disease. Improved PFS was also noted among patients with stage III disease compared with those with stage IV or recurrent disease. Notably, all patients with stage III disease in this institutional series received radiation therapy, in contrast to the RUBY trial, where radiation was not administered, Lantsman noted. None of the patients with stage III disease who received radiation experienced immune-related adverse effects (AEs), she added.

In patients with stage IV disease, high-risk histologic subtypes were more frequently observed, Lantsman continued. The AE profile was consistent with that reported in the RUBY trial, and immune checkpoint inhibitors were generally well tolerated, with only 9% of patients discontinuing treatment due to AEs, she said. Among the 7 patients (28%) who experienced disease progression, post-progression treatments included pembrolizumab (Keytruda), antibody-drug conjugates, clinical trials, and other therapies, Lantsman stated

Of the 17 patients who remained progression-free, 71% had low-risk endometrioid histology. At the time of analysis, 2 patients had died of their disease, she noted. These findings support the feasibility of integrating dostarlimab into frontline treatment for advanced or recurrent endometrial cancer in real-world settings, Lantsman concluded.