BACKGROUNDSeveral economic studies have assessed the cost-effectiveness of programmed cell death protein-1 (PD-1) inhibitors compared to second-line chemotherapy in treating esophageal squamous cell carcinoma (ESCC). However, there is a lack of economic comparisons among the different PD-1 inhibitors.AIMThis study aimed to assess the cost-effectiveness of PD-1 inhibitors (nivolumab, pembrolizumab, camrelizumab, and tislelizumab) in second-line treatment for advanced or metastatic ESCC within the Chinese healthcare system.METHODThe clinical trials were systematically retrieved from PubMed, Embase, Web of Science, and the Cochrane Library. We established a fractional polynomials model to conduct a network meta-analysis, enabling the calculation of hazard ratios and expected survival rates. Economic outcomes were estimated using a partitioned survival model. The costs and utilities were gathered from published sources. The threshold for willingness-to-pay (WTP) for a quality-adjusted life year (QALY) was set at three times China's per capita gross domestic product in 2022. Sensitivity analyses (SA) were performed to address uncertainties in the model.RESULTSFour phase III randomized controlled trials were included, evaluating the cost-effectiveness of four PD-1 inhibitors, camrelizumab, nivolumab, tislelizumab, and pembrolizumab, compared to chemotherapy for the second-line treatment of advanced or metastatic ESCC. For camrelizumab, nivolumab, tislelizumab, and pembrolizumab, the corresponding incremental cost-effectiveness ratios were $27,375.43/QALY, $205,312.19/QALY, $9,266.73/QALY, and $220,368.10/QALY, respectively. The SA results indicated the robustness of the base analysis findings.CONCLUSIONFrom the Chinese healthcare system, under the WTP of $38,253.48/QALY, tislelizumab is a cost-effective treatment option for the second-line treatment of advanced or metastatic ESCC.