Health Canada has approved Merck’s anti-PD-1 therapy Keytruda (pembrolizumab) as a perioperative treatment for adults with resectable, locally advanced head and neck squamous cell carcinoma whose tumours express PD-L1 with a Combined Positive Score of one or higher. The regimen allows two cycles of neoadjuvant Keytruda, followed by surgery, adjuvant radiotherapy with or without cisplatin plus three additional cycles of the drug, and up to 12 further cycles as monotherapy. The decision is based on results from the 714-patient, open-label Phase 3 KEYNOTE-689 study. In PD-L1–positive patients, perioperative Keytruda cut the risk of event-free survival events by 30% versus standard care (hazard ratio 0.70; 95% CI 0.55–0.89; p=0.0014), extending median event-free survival to 59.7 months from 29.6 months. The most common treatment-related adverse events were radiation skin injury and stomatitis; grade 3–5 stomatitis occurred in 11.6% of patients. Canada’s authorisation follows a similar U.S. Food and Drug Administration approval in June and expands Keytruda’s growing head-and-neck cancer franchise, first launched in 2015. According to the Canadian Cancer Society, about 8,100 new head and neck cancer cases were diagnosed in the country last year, underscoring the potential clinical impact of an earlier immunotherapy option.