NRG-GY018 Trial: Long-Term Survival Benefit Confirmed for Pembrolizumab in Endometrial Cancer

Key Findings

For dMMR patients, 48-month survival was 79% for pembrolizumab vs. 60% for placebo (HR 0.56; 95% CI 0.34-0.92).

The NRG-GY018 trial evaluated pembrolizumab plus chemotherapy versus placebo plus chemotherapy in patients with advanced or recurrent endometrial cancer. A prolonged follow-up analysis showed a sustained overall survival benefit in both dMMR and pMMR populations.

For pMMR patients, median overall survival was 44.4 months vs. 35.1 months, a difference of 9.3 months. This survival benefit persisted despite high rates of post-protocol immunotherapy use in control arms (≥93% dMMR, ≥81% pMMR).

Background

Historically, advanced or recurrent endometrial cancer has had poor outcomes with limited treatment progress. The trial enrolled 809 patients randomly assigned to pembrolizumab or placebo with carboplatin and paclitaxel. The data cutoff was April 14, 2026, with information fractions of 43% (dMMR) and 82% (pMMR).

Expert Commentary

Ramez N. Eskander, MD, lead author, stated that the findings address a long-standing treatment gap and that the survival advantage in both MMR subgroups adds confidence to the regimen regardless of MMR status.

He noted that in pMMR patients, the persistent benefit despite post-study immunotherapy suggests early incorporation gives the greatest clinical benefit.

Funding

Supported by NRG Oncology Operations grant U10CA180868 and SDMC grant U10CA180822 from NCI, with additional funding from Merck & Co., Inc.