Cancer Therapy AdvisorSustained OS Seen in Endometrial Cancer with Pembro Plus Carboplatin-Paclitaxel

ℹ️ Observational Association Only Evidence

The phase 3 NRG-GY018 trial (NCT03914612) evaluated pembrolizumab plus carboplatin-paclitaxel versus placebo plus chemotherapy in advanced or recurrent endometrial cancer, stratified by mismatch repair status. At a median follow-up of 49 months (dMMR) and 44 months (pMMR), updated OS data were presented at ASCO 2026 alongside poststudy ICI use patterns.

Clinical Considerations

• In the dMMR cohort (n=223), 48-month OS rates were 78.6% vs 60.4% (HR 0.56; 95% CI 0.34–0.92), with median OS not reached in either arm
• In the pMMR cohort (n=586), median OS was 44.4 vs 35.1 months (HR 0.86; 95% CI 0.69–1.08), a clinically meaningful gap that did not cross the significance threshold at this analysis
• High poststudy ICI crossover in placebo arms complicates OS interpretation: 93.2% of dMMR placebo patients and 81.1% of pMMR placebo patients received subsequent ICI therapy
• Poststudy ICI patterns differed by MMR status. dMMR placebo patients predominantly received ICI monotherapy; pMMR placebo patients more often received lenvatinib plus pembrolizumab.

Practice Applications

• Recognize that robust dMMR OS benefit at 48 months reinforces pembrolizumab plus chemotherapy as the standard approach for this subgroup
• Interpret pMMR OS data with caution: the 9-month median OS advantage is clinically notable but statistically inconclusive at this information fraction
• Monitor for final OS readout in the pMMR cohort, where high crossover rates may continue to attenuate the survival signal
• Consider MMR status central to patient counseling on expected magnitude of benefit from this regimen