The U.S. Food and Drug Administration granted approval to pembrolizumab as a perioperative treatment for resectable locally advanced head and neck squamous cell carcinoma expressing PD-L1. This milestone follows successful results from the phase 3 KEYNOTE-689 trial led by Dana-Farber Brigham Cancer Center and Washington University, demonstrating improved event-free survival and tumor shrinkage. This approval marks a significant paradigm shift in managing surgically treated head and neck cancers.