At the ESMO Congress 2026, Shannon N. Westin (Houston, United States) presented updated results from the phase III DUO-E/GOG-3041/ENGOT-EN10 trial (NCT04269200), evaluating durvalumab plus carboplatin and paclitaxel, followed by maintenance durvalumab with or without olaparib, in patients with advanced or recurrent endometrial cancer.
The interim analysis demonstrated a median overall survival (OS) of 51.1 months with durvalumab plus olaparib maintenance compared with 39.6 months in the chemotherapy control group, representing an 11.5-month numerical improvement. However, the interim OS comparisons did not meet the prespecified criteria for statistical significance.
Methods
DUO-E is a randomized phase III trial evaluating the addition of durvalumab, a PD-L1 inhibitor, and olaparib, a PARP inhibitor, to first-line treatment for advanced or recurrent endometrial cancer.
A total of 718 patients were randomized 1:1:1 into three treatment groups:
- Control: Carboplatin plus paclitaxel (CP), followed by control maintenance.
- Durvalumab: Carboplatin plus paclitaxel and durvalumab, followed by durvalumab maintenance.
- Durvalumab plus olaparib: Carboplatin plus paclitaxel and durvalumab, followed by durvalumab plus olaparib maintenance.
The trial previously demonstrated statistically significant progression-free survival benefits with both durvalumab-containing regimens compared with chemotherapy alone.
The prespecified interim analysis evaluated overall survival, time to subsequent therapies, treatment discontinuation or death, and updated safety outcomes. OS was also assessed according to mismatch repair status.
Key Takeaways
At the February 2, 2026, data cutoff, the interim OS analysis had reached 52% maturity, with a median follow-up of 52 months among censored patients.
- Median overall survival: 51.1 months with durvalumab plus olaparib, 40.7 months with durvalumab alone, and 39.6 months in the chemotherapy control group.
- Durvalumab plus olaparib: OS favored the combination (HR 0.77; 95% CI, 0.60–0.98; nominal p=0.037), but the interim comparison did not meet the prespecified statistical significance threshold.
- Durvalumab alone: A numerical OS benefit was observed compared with chemotherapy alone (HR 0.87; 95% CI, 0.68–1.11; p=0.259).
- dMMR subgroup: Median OS was not reached in either durvalumab-containing group, compared with 50.2 months in the control group. OS hazard ratios were 0.57 with durvalumab and 0.43 with durvalumab plus olaparib.
- pMMR subgroup: Median OS was 45.8 months with durvalumab plus olaparib versus 37.8 months with chemotherapy alone (HR 0.85; 95% CI, 0.65–1.11).
- Secondary outcomes: Time to first and second subsequent therapy and treatment discontinuation or death consistently favored the durvalumab-containing regimens.
- Safety: Both regimens continued to demonstrate manageable safety profiles, with no new safety concerns identified.
- Time to first subsequent therapy or death (TFST): Median TFST was 16.1 months with durvalumab plus olaparib, 13.6 months with durvalumab alone, and 10.8 months in the control group. Both durvalumab-containing regimens favored improved outcomes (HR 0.61 and 0.79, respectively).
- Long-term survival in dMMR disease: Median OS was not reached in either durvalumab-containing arm. The OS hazard ratio was 0.43 (95% CI, 0.21–0.83) with durvalumab plus olaparib and 0.57 (95% CI, 0.30–1.05) with durvalumab alone, compared with chemotherapy.
Conclusion
The updated DUO-E findings demonstrated favorable interim overall survival outcomes with durvalumab-containing regimens in patients with advanced or recurrent endometrial cancer.
The 11.5-month numerical improvement in median OS with durvalumab plus olaparib maintenance, alongside an 8.0-month difference in the pMMR subgroup, suggests potential long-term clinical benefit. However, the prespecified statistical significance criteria for overall survival were not met at this interim analysis.
The trial previously met both primary progression-free survival endpoints, supporting durvalumab-based treatment strategies in advanced or recurrent endometrial cancer.
Consistent improvements in time to subsequent therapy and treatment discontinuation or death, together with no new safety signals, further support the clinical relevance of the findings.
Overall survival will be formally reassessed at the final analysis, with follow-up ongoing to establish the long-term treatment benefit.
Source: ESMO Congress 2026, Abstract LBA37; DUO-E/GOG-3041/ENGOT-EN10 (NCT04269200).
