Cost-utility analysis of three PD-1 inhibitors combined with chemotherapy in the first-line treatment of locally advanced or metastatic esophageal squamous carcinoma in China

OBJECTIVE: To evaluate the economics of sintilimab combination chemotherapy versus chemotherapy and sintilimab combination chemotherapy versus camrelizumab/ toripalimab combination chemotherapy in the first-line treatment of locally advanced or metastatic esophageal squamous carcinoma (ESCC) from the perspective of the Chinese health system. METHODS: A partitioned survival model (PSM) with a tracked time horizon of 5 years was developed. In the basal analysis, a direct cost-utility comparison of sintilimab + chemotherapy vs. chemotherapy in first-line treatment of advanced ESCC was performed based on survival data from the ORIENT-15 trial. Cost and utility value data were obtained from relevant databases or published literature, and the robustness of the model was assessed using one-way sensitivity analysis and probabilistic sensitivity analysis (PSA). In the exploratory analysis, the cost-utility of sintilimab + chemotherapy vs. camrelizumab/ toripalimab + chemotherapy was indirectly compared by Network Meta-Analysis (NMA) combined with hazard ratio (HR). RESULTS: Sintilimab in combination with chemotherapy resulted in 0.33 quality-adjusted life years (QALYs) more than chemotherapy with an incremental cost-effectiveness ratio (ICER) of 25,409.27 USD/QALY, which was lower than the willingness-to-pay (WTP). Sensitivity analysis showed that the utility value of stable disease and the price of sintilimab had the greatest impact on outcome stability. Exploratory analysis indicate that toripalimab plus chemotherapy yields an additional 0.04 QALYs compared with sintilimab plus chemotherapy, with an ICER of 9,953.24 USD/QALY. In contrast, camrelizumab plus chemotherapy yields 0.05 fewer QALYs compared with sintilimab plus chemotherapy. CONCLUSION: For the first-line treatment of locally advanced or metastatic ESCC, the addition of sintilimab to conventional chemotherapy regimens was economical. Among similar PD-1 inhibitors, the toripalimab plus chemotherapy regimen is more costly but more effective than the sintilimab plus chemotherapy regimen, and is cost-effective at the WTP threshold of 3 × GDP per capita. In contrast, the camrelizumab plus chemotherapy regimen is dominated (higher cost and worse effectiveness) by the sintilimab plus chemotherapy regimen.