Merck (NYSE: MRK), known as MSD outside of the United States and Canada, announced results from the Phase 3 KEYNOTE-689 trial evaluating KEYTRUDA® (pembrolizumab). The trial focused on perioperative treatment for patients with stage III or IVA, resected, locally advanced head and neck squamous cell carcinoma (LA-HNSCC). The interim analysis showed that KEYTRUDA significantly improved event-free survival (EFS) when used as part of a perioperative treatment regimen with adjuvant standard of care (SOC) radiotherapy with or without cisplatin. This was compared to adjuvant standard of care (SOC) radiotherapy with or without cisplatin alone.
The data, presented at the American Association for Cancer Research (AACR) Annual Meeting 2025, demonstrated that treatment with KEYTRUDA before surgery, followed by its combination with standard of care radiotherapy after surgery, reduced the risk of EFS events by 34% in the combined positive score (CPS) ≥10 population, by 30% in the CPS ≥1 population, and by 27% in the intent-to-treat (ITT) population. Median EFS was notably higher in the KEYTRUDA plus SOC group compared to the SOC group across all populations.
The safety profile of KEYTRUDA was consistent with previously reported studies, with no new safety signals identified. Immune-mediated adverse events occurred in 43.2% of patients receiving the KEYTRUDA regimen, most commonly hypothyroidism.
Dr. Ravindra Uppaluri, co-principal investigator, highlighted the importance of these results for patients with resectable, locally advanced head and neck squamous cell carcinoma. Dr. Douglas Adkins added that the addition of immunotherapy using KEYTRUDA resulted in a significant reduction in the risk of event-free survival events by 27%, compared with standard of care therapy alone.
A supplemental Biologics License Application (sBLA) for KEYTRUDA based on data from KEYNOTE-689 is under priority review with the U.S. Food and Drug Administration (FDA).
— new from Merck