ASCO Results on Endometrial Cancer

Yesterday, the 26th NOGGO Update on Gynecological Oncology took place, where important studies on endometrial cancer from ASCO 2025 were presented. We were on site and would like to share the most important findings:

DUO-E Study – ctDNA as an Important Marker

The DUO-E Study had already shown in 2024 that the combination of chemotherapy, durvalumab, and olaparib significantly improved disease progression in both mismatch repair-deficient (dMMR) and -proficient (pMMR) patients. A current analysis of circulating tumor DNA (ctDNA) now confirms:

• Patients with high ctDNA levels at baseline have a higher risk of recurrence.

• In all treated women, ctDNA levels decreased more under combination therapy compared to chemotherapy alone.

• Particularly the addition of durvalumab led to rapid ctDNA reduction and kept it low during the maintenance phase.

• The additional administration of olaparib during maintenance had a further positive effect on ctDNA reduction in pMMR patients.
  This shows that the therapy not only delays progression but also demonstrably reduces tumor burden.

RUBY Study – Dostarlimab Plus CTX Confirms Benefit

Extended analyses of the RUBY Study show that the combination of dostarlimab and chemotherapy provides a lasting clinical benefit in both advanced and recurrent endometrial cancer:

• The time to first treatment discontinuation (TFST) and overall survival benefit could be extended – regardless of mismatch status (dMMR or pMMR).

• Quality of life did not suffer under immunotherapy either – on the contrary: patients recovered in comparable time as under standard therapy.
  This clearly confirms dostarlimab plus chemotherapy as the new standard.

Phase 2 Study – Letrozole, Abemaciclib & Metformin

In a smaller study in estrogen receptor-positive, recurrent endometrial cancer, the combination letrozole + abemaciclib + metformin achieved an objective response rate (= proportion of patients in whom a tumor demonstrably becomes smaller or disappears completely) of 32%. The median time during which the disease did not progress (PFS) was 19.4 months, and no patient had to discontinue therapy due to side effects.
This indicates a safe and effective new therapeutic approach – although coverage by health insurance companies still needs to be reviewed.

EXPRESSION XI – Survey Study

The EXPRESSION XI Study clearly showed: patients want structured follow-up care programs, especially regarding nutrition during therapy and physical activity afterward. This strengthens the call for targeted lifestyle programs as an integral part of follow-up care.

Conclusion for Patients & Clinics

The presented studies support key advances:

• DUO-E: Molecular tumor burden can be measured through therapy – a step toward individualized management.

• RUBY: Dostarlimab plus chemotherapy has proven itself as the new standard treatment – effective and quality-of-life friendly.

• Letrozole combination: Shows promising activity in ER-positive, recurrent endometrial cancer.

• Lifestyle programs: Are important for patients and should be more firmly anchored in the healthcare system.

Despite these developments, there are currently no changes to the guidelines yet. However, the data are promising and pave the way for future treatment options.