DOMENICA: dostarlimab versus chemotherapy alone in first-line MMR-deficient advanced endometrial cancer patients.

Immunotherapy (IO) in endometrial cancer (EC) is the standard of care in the second line setting in combination with an anti-angiogenic agent. Randomized clinical trials have reported results supporting the addition of IO to chemotherapy (paclitaxel plus carboplatin) in the first-line setting in advanced EC patients in the global population, with high efficacy in mismatch repair deficient (MMRd) patients. These trials were not designed to answer this de-escalation question in the MMRd population, who benefit greatly from IO.The international, randomized phase III, DOMENICA trial compares first-line dostarlimab versus chemotherapy alone (with planned cross-over) for advanced MMRd EC. Our primary endpoint will be progression-free survival. The key secondary endpoints will be overall survival, safety and quality of life [NCT05201547].