OBJECTIVE To analyze the cost-effectiveness of serplulimab combined with chemotherapy versus chemotherapy alone in the first-line treatment for advanced esophageal squamous cell carcinoma(ESCC) from the perspective of the healthcare system in China.

METHODS A three state partitioned survival model was established to simulate the clinical effectiveness and cost of serplulimab combined with chemotherapy versus chemotherapy lone in the first-line treatment for ESCC. Survival data in the model were derived by extrapolation of Kaplan-Meier curves from the ASTRUM-007 study. Only direct medical costs were included in the cost calculation, and utility values were obtained from the literature. The incremental cost-effectiveness ratio(ICER) was the main indicator of output. The willingness-to-pay(WTP) threshold was set at 3 times gross domestic product per capita 2022 in China. Sensitivity analysis was performed to assess the effect of parameter uncertainty on the model, and subgroup analysis and scenario analysis were also conducted.

RESULTS The results of basic analysis showed that the ICER generated by serplulimab combined with chemotherapy was ￥613 790/QALY compared with chemotherapy, which was far above the WTP threshold. The results of one-way sensitivity analysis demonstrated the price of serplulimab, weight of patients and utility value in progression-free survival stage had the greatest impact on the model. Probabilistic sensitivity analysis illustrated that serplulimab combined with chemotherapy was not economical in 1 000 simulations. The results of subgroup analysis and scenario analysis were consistent with the results of the base analysis.

CONCLUSION Serplulimab combined with chemotherapy is not economical for the first-line treatment of advanced ESCC in comparison with chemotherapy.