Cost-utility analysis of triplet therapy using gemcitabine, cisplatin, and S-1 for the primary treatment of advanced biliary tract cancer.

Abstract Background The results of the KHBO1401-MITSUBA trial suggested the effectiveness of triplet therapy using gemcitabine, cisplatin, and S-1; however, the cost-effectiveness of this treatment regimen remains unclear. Aim We conducted a cost-utility analysis comparing triplet therapy using gemcitabine, cisplatin, and S-1 and doublet therapy using gemcitabine and cisplatin for advanced biliary tract cancer from the perspective of a Japanese healthcare payer to investigate the economic sustainability of healthcare interventions. Method Based on the results of the KHBO1401-MITSUBA clinical trial, a partitioned survival model set over a 10-year time horizon was developed. Cost and utility data were sourced from earlier studies. Health outcomes were measured as quality-adjusted life-years. Direct medical costs included drug costs and medical fees. The uncertainty and robustness of the model were evaluated using one-way and probabilistic sensitivity analyses. The willingness-to-pay threshold was set at 7.5 million Japanese yen. Results Base case analysis revealed that the incremental cost-effectiveness ratio for triplet therapy was 5,257,388 Japanese yen (47,881 United States dollars) per quality-adjusted life-year. The one-way sensitivity analysis indicated that parameters influencing the overall survival curve for doublet and triplet therapy affected the incremental cost-effectiveness ratio. Probabilistic sensitivity analysis suggested that triplet therapy had a 72.5 % chance of being cost-effective at a willingness-to-pay threshold of 7.5 million yen per quality-adjusted life-year. Conclusion Triplet therapy using gemcitabine, cisplatin, and S-1 is cost-effective in the primary treatment of biliary tract cancer in the Japanese healthcare system.