An immunotherapy-based regimen combining durvalumab and the PARP inhibitor, olaparib, demonstrated encouraging long-term survival outcomes for patients with advanced or recurrent endometrial cancer, according to new trial results presented by researchers from The University of Texas MD Anderson Cancer Center.
In the global Phase 3 DUO-E trial, treatment with durvalumab plus chemotherapy followed by durvalumab and olaparib achieved a median overall survival of 51.1 months, which was 11.5 months longer than with chemotherapy alone. The findings were presented today at the European Society for Medical Oncology Congress 2026 by principal investigator Shannon Westin, M.D., professor of Gynecologic Oncology and Reproductive Medicine.
These results demonstrate that combining immunotherapy with a PARP inhibitor can deliver durable survival benefits for patients with advanced or recurrent endometrial cancer. The findings are particularly noteworthy for patients with pMMR tumors, who represent the majority of cases and have traditionally had fewer effective treatment options."
Shannon Westin, M.D., Professor of Gynecologic Oncology and Reproductive Medicine, MD Anderson Cancer Center
What are the other key findings of the DUO-E trial?
The trial randomized 718 patients with advanced or recurrent endometrial cancer to receive one of three treatment regimens. One group received chemotherapy alone followed by placebo in the maintenance phase. The other two groups received chemotherapy with durvalumab followed by durvalumab with or without olaparib in the maintenance phase.
The study previously met its primary progression-free survival endpoints. The current analysis evaluated overall survival and long-term safety profiles. No new safety concerns were observed, and side effects remained consistent with previous findings.
Researchers also reported durable benefits across several secondary endpoints. Patients receiving durvalumab followed by durvalumab and olaparib experienced longer periods before requiring subsequent therapy and remained on treatment longer than those receiving chemotherapy alone. At 36 months, 63.4% of patients in the durvalumab-plus-olaparib arm were alive, compared with 52% of patients in the chemotherapy arm.
Researchers also observed additional benefits among patients with mismatch repair proficient (pMMR) tumors, who represent the majority of endometrial cancer cases and have historically had fewer effective treatment options. The addition of olaparib, a PARP inhibitor that interferes with cancer cells' DNA repair mechanisms, may help explain the broader benefit seen across patient subgroups.
Why are these findings important?
Endometrial cancer is the most common gynecologic cancer in the U.S. and approximately 66,000 women are diagnosed each year.
Women with advanced or recurrent endometrial cancer have limited treatment options and historically face poor outcomes once the disease spreads or returns after initial treatment. The results suggest that combining immunotherapy with targeted maintenance therapy may help patients live longer while also delaying the need for additional treatment.
The results support an approach that combines immunotherapy and targeted therapy earlier in the treatment journey, before the disease progresses.
Researchers will continue the DUO-E study to look into a final anlysis of overall survival.
Starting survivorship care earlier improves head and neck cancer survival