Abstract
BACKGROUND: Programmed death-1 (PD-1) inhibitors combined with chemotherapy have become a standard first-line treatment for advanced oesophageal squamous cell carcinoma (ESCC). Given the high costs associated with immunotherapy, evaluating the cost-effectiveness of different PD-1 inhibitors in the Chinese healthcare setting is essential for guiding treatment decisions and policy development. METHODS: A cost-effectiveness analysis was conducted comparing six PD-1 inhibitors-sintilimab, toripalimab, tislelizumab, camrelizumab, serplulimab, and pembrolizumab-combined with chemotherapy for first-line treatment of advanced ESCC. A partitioned survival model was used to calculate incremental cost-effectiveness ratios (ICERs) from healthcare system perspective, with a willingness-to-pay (WTP) threshold set at $36,598.19 per quality-adjusted life year (QALY). Sensitivity analyses were performed to evaluate the robustness of the results. RESULTS: The ICERs for toripalimab, camrelizumab, pembrolizumab, serplulimab, sintilimab, and tislelizumab were $32,356.79/QALY, $48,410.64/QALY, $312,743.54/QALY, $121,200.84/QALY, $29,663.42/QALY, and $35,304.33/QALY, respectively. Sintilimab, toripalimab, and tislelizumab were below the WTP threshold. Among all regimens, the top three in life years (LYs) gained were toripalimab, serplulimab, and tislelizumab. Sensitivity analysis showed that utility values and drug prices were key factors influencing ICERs. Probabilistic analysis indicated that toripalimab, sintilimab, and tislelizumab had the highest probabilities of being cost-effective, at 83.1%, 81.4%, and 70.0%, respectively. CONCLUSION: Sintilimab, toripalimab, and tislelizumab are the most cost-effective PD-1 inhibitors when combined with chemotherapy for the first-line treatment of advanced ESCC in China, with ICERs below the WTP threshold. While all six PD-1 inhibitors demonstrated clinical benefits, pembrolizumab and serplulimab were less favourable from a cost-effectiveness standpoint. Sensitivity analysis confirmed that drug prices and utility values are significant determinants of cost-effectiveness.