OBJECTIVES: The National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO) had recently updated their guidelines to recommend ivosidenib over modified FOLFOX (mFOLFOX) for advanced intrahepatic cholangiocarcinoma (ICC) patients with isocitrate dehydrogenase-1 (IDH1) mutations. However, the Taiwan National Health Insurance (NHI) only reimburses fluorouracil/leucovorin (5-FU/LV) for these patients. As there is currently no cost-effectiveness analysis (CEA) of ivosidenib, this study aims to evaluate the cost-effectiveness of ivosidenib in previously treated IDH1-mutant ICC patients compared with mFOLFOX or 5-FU/LV chemotherapy regimens from the Taiwan NHI’s perspective to help inform future reimbursement decisions.

METHODS: The cost-effectiveness of ivosidenib compared with different chemotherapy regimens was evaluated with a 3-state partitioned survival model over a 10-year time horizon. The willingness-to-pay threshold was set at three times the 2022 gross domestic product (GDP) per capita (NT$ 2,928,570). Ivosidenib, mFOLFOX, and 5-FU/LV efficacies were extracted from the ClarlDHy, ABC06, and NIFTY trials. The medication cost of ivosidenib and chemotherapy regimens were obtained from the US average wholesale price (AWP) and NHI, respectively. Non-medication costs and utilities were gathered from published literature. Deterministic sensitivity analyses (DSA) and probabilistic sensitivity analyses (PSA) were also conducted.

RESULTS: Incremental costs of ivosidenib compared against the two regimens were 3,769,822 (mFOLFOX) and 3,902,732 (5FU/LV). The incremental quality-adjusted life years (QALYs) of ivosidenib over the two regimens were 0.39 (mFOLFOX) and 0.45 (5FU/LV). The incremental cost-effectiveness ratios (ICER) of ivosidenib over the two regimens were 9,670,485 (mFOLFOX) and 8,664,634 (5FU/LV), both higher than the WTP. The PSA comparing ivosidenib against the two regimens reported cost-effectiveness probabilities of 0.01% for mFOLFOX and 5FU/LV. The DSA indicates the medication cost of ivosidenib as the most sensitive parameters.

CONCLUSIONS: In our study, ivosidenib was not cost-effective compared with mFOLFOX or 5-FU/LV in IDH1-mutant ICC patients from the Taiwan NHI’s perspective.