Cost-effectiveness analysis of serplulimab in combination with cisplatin plus 5-fluorouracil chemotherapy compared to cisplatin plus 5-fluorouracil chemotherapy as first-line treatment for advanced or metastatic esophageal squamous cell carcinoma in China.

Background: This study evaluated the cost-effectiveness of serplulimab plus chemotherapy Methods: A partitioned survival model based on ASTRUM-007 trial patient characteristics was developed. Efficacy, safety, and medical/economic data were obtained from the trial and real-world clinical practice. Costs, quality-adjusted life years (QALY), and incremental cost-effectiveness ratios (ICERs) were calculated for both treatment strategies. Sensitivity, subgroup, and scenario analyses were performed to assess the uncertainty impact. Results: Serplulimab combined with chemotherapy yielded an ICER of US$ 53,538.27/QALY. Deterministic sensitivity analysis identified patient survival and serplulimab price as influential parameters. Probabilistic sensitivity analysis showed a 47.33% probability of cost-effectiveness at a willingness-to-pay (WTP) threshold of US$ 53,541/QALY and 0.05% at three times China's GDP per capita. Subgroup analysis revealed that patients with a programmed death-ligand 1 (PD-L1) expression combined positive score (CPS) ⩾10 had a lower hazard ratio (0.59) and ICER (US$ 29,935.23/QALY), with a 95.36% probability of cost-effectiveness. Scenario analysis demonstrated that the drug donation discount policy significantly increased the likelihood of cost-effective serplulimab-chemotherapy combinations in Jiangsu, Fujian, and Guangdong at 99.99%, 99.90%, and 94.16%, respectively. Conclusion: Compared to chemotherapy alone, serplulimab combined with chemotherapy is currently not a cost-effective first-line treatment for advanced/metastatic ESCC in China. However, as serplulimab plus chemotherapy regimens evolve and price competition among programmed death 1 (PD-1) inhibitors intensifies, this combination may become a cost-effective treatment option.