Recently, updated data from KEYNOTE-048 revealed that pembrolizumab with or without chemotherapy could improve progression-free survival (PFS)2 compared with cetuximab plus chemotherapy in recurrent or metastatic head and neck squamous cell carcinoma (HNSCC).A Markov structure was conducted to evaluate the cost and effectiveness of pembrolizumab monotherapy or pembrolizumab plus chemotherapy vs. cetuximab plus chemotherapy in the first-line treatment of recurrent or metastatic HNSCC from the United States payer's perspective. Total cost, health outcomes, and incremental cost-effective ratios (ICERs) were estimated. Additional analyses were conducted in the total population and in two different programmed cell death 1 ligand 1 (PD-L1) combined positive scores (CPSs) (≥1 and ≥ 20) population. Sensitivity analysis were used to test the stability of the model.When compared with cetuximab plus chemotherapy, the pembrolizumab monotherapy strategy was dominated by lower cost and better efficacy in all three populations. The incremental costs and quality adjusted life years (QALYs) yielded by pembrolizumab plus chemotherapy compared with cetuximab plus chemotherapy were $16016.88 and 0.11 in the total population, and $24467.47 and 0.18 and $30448.46 and 0.20 in the populations with a PD-L1 CPS ≥ 1 and CPS ≥ 20, respectively, leading to ICERs of $147876.14, $134237.84, and $153660.78 per QALY, respectively.First-line treatment with pembrolizumab or pembrolizumab plus chemotherapy are cost-effective strategies compared with cetuximab plus chemotherapy when the value of willingness-to-pay (WTP) was $150000 per QALY for the total and PD-L1 CPS ≥ 1 populations with recurrent or metastatic HNSCC.Copyright © 2022 Elsevier Ltd. All rights reserved.