Merck’s Keytruda met primary endpoint in Phase 3 carcinoma study

Merck announced that the Phase 3 KEYNOTE-689 trial evaluating Keytruda – pembrolizumab -, Merck’s anti-PD-1 therapy, as a perioperative treatment for patients newly diagnosed with stage III or IVA, resected, locally advanced head and neck squamous cell carcinoma – LA-HNSCC – met its primary endpoint of event-free survival. The study evaluated Keytruda as neoadjuvant therapy, then continued after surgery in combination with standard-of-care radiotherapy as adjuvant therapy, followed by Keytruda as maintenance therapy, vs. adjuvant radiotherapy alone. At a pre-specified first interim analysis conducted by an independent Data Monitoring Committee, there was a statistically significant and clinically meaningful improvement in EFS for patients receiving the Keytruda perioperative treatment regimen. The study also showed a statistically significant improvement in major pathological response, a key secondary endpoint, for patients in the Keytruda arm vs. adjuvant radiotherapy alone. The safety profile of Keytruda was consistent with that observed in previously reported studies; no new safety signals were identified. A trend toward improvement in overall survival, another key secondary endpoint, was observed for Keytruda as neoadjuvant treatment and Keytruda in combination with standard-of-care radiotherapy as treatment after surgery and maintenance therapy with Keytruda. The OS results did not reach statistical significance in patients whose tumors were PD-L1 Combined Positive Score greater than or equal to10 at the time of this first interim analysis. OS will be evaluated at the next interim analysis.