Dr Westin on Interim Overall Survival Data From DUO-E in Advanced or Recurrent Endometrial Cancer

“We're seeing a beautiful flattening of the curves, which indicates to me that this [benefit] is going to be retained.”

Shannon N. Westin, MD, MPH, FACOG, a professor and clinical medical director in the Department of Gynecologic Oncology and Reproductive Medicine in the Division of Surgery, director of Early Drug Development in the Department of Gynecologic Oncology and Reproductive Medicine, and co-director of the Ovarian Cancer Moonshot Program at The University of Texas MD Anderson Cancer Center, discussed interim overall survival (OS) data from the phase 3 DUO-E/GOG-3041/ENGOT-EN10 trial (NCT04269200) evaluating durvalumab (Imfinzi) plus carboplatin/paclitaxel followed by maintenance durvalumab with or without olaparib (Lynparza) in patients with advanced or recurrent endometrial cancer, which were presented at the 2026 ESMO Congress.

DUO-E previously met its dual primary end points. In the intention-to-treat (ITT) population, progression-free survival (PFS) improved with durvalumab (HR, 0.71; 95% CI, 0.57-0.89; P = .003) and durvalumab plus olaparib (HR, 0.55; 95% CI, 0.43-0.69; P < .0001) vs chemotherapy alone. In patients with mismatch repair–deficient (dMMR) disease, durvalumab clearly outperformed control, whereas olaparib added little to PFS, which Westin said was surprising and may reflect the high bar set by immunotherapy in this group. Durvalumab plus olaparib had the greatest impact in mismatch repair–proficient (pMMR) disease (HR, 0.57; 95% CI, 0.44-0.73), she noted.

At 52.1% maturity, the interim analysis showed a nonstatistically significant but clinically meaningful overall survival (OS) improvement in the ITT population, Westin said. The risk of death was reduced by 13% with durvalumab and 23% with durvalumab plus olaparib vs control, the latter translating to an 11.5-month improvement in OS, she explained. Statistical significance has not yet been met because alpha was allocated across the interim and final analyses, Westin noted.

In the dMMR subgroup, durvalumab plus olaparib reduced the risk of death by 57% vs control, compared with 43% for durvalumab alone, Westin said, adding that this exploratory finding suggests the combination may offer something for this population as well. In the pMMR subgroup, olaparib strengthened the OS improvement, with a 15% reduction in the risk of death and an 8-month OS gain, which Westin said compares favorably with prior immunotherapy-plus-chemotherapy trials.

Westin added that she is eager to see the final OS analysis, which is expected at approximately 60% maturity within the next year.