The FDA approved pembrolizumab for patients with resectable locally advanced head and neck squamous cell carcinoma expressing PD-L1, marking the first checkpoint inhibitor approval in this curative perioperative setting. The decision was based on positive findings from the KEYNOTE-689 Phase 3 trial demonstrating improved event-free survival and tumor shrinkage, representing a paradigm shift in head and neck cancer treatment led by Dana-Farber Brigham Cancer Center researchers.