Economic evaluation of perioperative pembrolizumab plus standard of care as treatment for resectable locally advanced head and neck squamous cell carcinoma in the United States.

[AIMS] In the phase 3 KEYNOTE-689 trial (NCT03765918) among patients with resectable locally advanced head and neck squamous cell carcinoma (LA HNSCC), perioperative pembrolizumab (pembrolizumab before surgery, then continued with standard-of-care [SOC] radiotherapy +/- cisplatin after surgery followed by pembrolizumab alone) significantly prolonged event-free survival vs. SOC alone, both in the intention-to-treat population and PD-L1 combined positive score (CPS) ≥1 subgroup. Perioperative pembrolizumab + SOC received Food and Drug Administration approval in June 2025 for resectable LA HNSCC expressing PD-L1 (CPS ≥ 1). The present study evaluated the cost-effectiveness of perioperative pembrolizumab + SOC versus SOC in this indication, from a US healthcare payer perspective.

[MATERIALS AND METHODS] A Markov cohort model with four states (event-free, local recurrence, incurable recurrence/progression, death) was developed to estimate lifetime costs, life years (LYs), and quality-adjusted LYs (QALYs) with 3% annual discounting. Transition probabilities were fitted to patient-level time-to-event data from KEYNOTE-689 through parametric multistate modelling. Costs of initial and subsequent treatment, adverse events, disease management, and terminal care were estimated in 2025$ based on trial results, drug labels, public databases, and literature. Utilities were derived through analyses of EQ-5D-5L data collected in KEYNOTE-689. Deterministic and probabilistic sensitivity analyses were performed.

[RESULTS] Compared to SOC, perioperative pembrolizumab + SOC increased total costs by $82,311 and provided gains of 1.47 QALYs and 1.77 LYs. Incremental cost-effectiveness ratios of perioperative pembrolizumab + SOC vs. SOC were $55,863/QALY and $46,406/LY. Higher initial treatment costs of perioperative pembrolizumab (incurred mainly in Year 1) were partially offset by lower recurrence-related costs. At the typical $150,000/QALY threshold, perioperative pembrolizumab + SOC was cost-effective in 96% of probabilistic simulations.

[LIMITATIONS] Survival extrapolations beyond the available trial period are subject to uncertainty.

[CONCLUSIONS] Perioperative pembrolizumab + SOC was found to be cost-effective versus SOC for the treatment of resectable LA HNSCC with CPS ≥ 1.