Because of its low immunogenicity and associated risk of toxicity, sugemalimab is expected to reshape the first-line treatment landscape for non-small cell lung cancer (NSCLC) in China. However, it remains unclear whether the use of expensive sugemalimab is cost-effective in this population.A Markov model was constructed based on the GEMSTONE-302 study to assess the efficacy of sugemalimab in combination with chemotherapy for first-line treatment of metastatic NSCLC. Efficacy and safety data were entered, with costs and utility values derived from the literature, and incremental cost-effectiveness ratios (ICERs) were estimated, and univariate sensitivity analyses and probabilistic sensitivity analyses were performed. We also considered cost-effectiveness in two different treatment regimen scenarios after disease progression.Compared with the placebo plus platinum-based chemotherapy, patients with metastatic NSCLC treated with sugemalimab plus platinum-based chemotherapy saw an increase of 0.56 life-years (LYs) and 0.41 quality-adjusted life-years (QALYs), and patients with squamous NSCLC resulted in an ICER per QALY of $45,280.02. Patients with nonsquamous metastatic NSCLC resulted in an ICER of $45,294.15 per QALY. Univariate sensitivity analysis showed that disease-free survival utility had the greatest impact on the results. Probabilistic sensitivity analysis (PSA) showed that when the willingness-to-pay (WTP) for QALYs was $27,354/QALY, sugemalimab, in combination with platinum-based chemotherapy, was more cost-effective than the placebo.From a Chinese health care system perspective, first-line treatment of squamous or nonsquamous metastatic NSCLC with sugemalimab plus platinum-based chemotherapy may have cost-effectiveness compared with placebo plus platinum-based chemotherapy at a WTP threshold of $27,354/QALY.Copyright © 2022 Elsevier B.V. All rights reserved.