Longer follow-up from the phase III NRG-GY018 trial continues to support the addition of pembrolizumab to standard carboplatin/paclitaxel chemotherapy for patients with primary advanced-stage or recurrent endometrial cancer, according to findings presented during the Gynecologic Oncology Session at the 2026 ASCO Annual Meeting (Abstract 5502). The updated analysis demonstrated a sustained overall survival advantage with pembrolizumab in both mismatch repair–deficient (dMMR) and mismatch repair–proficient (pMMR) disease, despite extensive use of subsequent immunotherapy among patients initially assigned to the control arm.
Study Details
NRG-GY018 randomly assigned 809 patients to receive pembrolizumab or placebo in combination with carboplatin and paclitaxel. Earlier analyses had suggested an overall survival benefit with the addition of pembrolizumab. The current report, based on prolonged follow-up with an overall survival data cutoff of April 14, 2026, provides further evidence that the benefit persists over time.
Lead author Ramez N. Eskander, MD, of the University of California, San Diego, emphasized the significance of the findings for a disease setting that has historically seen limited therapeutic advances.
“These findings are particularly important because they address a long-standing gap in the treatment of advanced and recurrent endometrial cancer which historically has been plagued by poor outcomes and limited therapeutic progress,” Dr. Eskander stated. “The fact that the survival advantage persisted in the dMMR and pMMR EC populations, adds great confidence to the use [of] pembrolizumab in combination with chemotherapy in treatment of appropriately selected patients, irrespective of MMR status.”
Key Takeaways
Among patients with dMMR tumors, the addition of pembrolizumab continued to produce a meaningful survival advantage. At 48 months, 79% of patients treated with pembrolizumab remained alive, compared with 60% of those who received placebo (hazard ratio = 0.56, 95% confidence interval = 0.34–0.92). This benefit was observed even though at least 93% of dMMR patients in the control arm who received subsequent therapy went on to receive immunotherapy after the study.
The pMMR cohort also demonstrated a persistent numerical survival benefit. Median overall survival was 44.4 months with pembrolizumab plus chemotherapy compared with 35.1 months with chemotherapy alone. This advantage was maintained despite at least 81% of pMMR patients in the control arm receiving immunotherapy after study treatment.
Dr. Eskander noted that the findings in the pMMR population may suggest an advantage to introducing immunotherapy earlier in the treatment course. He commented that the “persistent no–statistically significant but notable benefit in overall survival, despite substantial post study immunotherapy utilization, may suggest that early incorporation of this regimen provides greatest clinical benefit.”
DISCLOSURE: For full disclosures of the study authors, visit coi.asco.org.
