COST-EFFECTIVENESS ANALYSIS OF VORASIDENIB FOR IDH1- OR IDH2-MUTANT GRADE 2 GLIOMA IN TAIWAN
Author(s)
Ming-Yu Hong, MS1, Wei-ming Huang, PharmD, MD1, Chen-Han Chueh, PhD2, Hsiao Ling Chen, BS, MS1, Chun-Wei Hsu, PhD3, Annabelle Day, MS3, Hsin-Chun Chou, MS1, Yi-Wen Tsai, PhD1.
1Institute of Health and Welfare Policy, National Yang Ming Chiao Tung University, Taipei, Taiwan, 2University of California San Diego, San Diego, CA, USA, 3Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.
1Institute of Health and Welfare Policy, National Yang Ming Chiao Tung University, Taipei, Taiwan, 2University of California San Diego, San Diego, CA, USA, 3Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.
OBJECTIVES: The INDIGO trial demonstrated that vorasidenib, a targeted inhibitor of isocitrate dehydrogenase 1 (IDH1) or 2 (IDH2), significantly prolongs progression-free survival compared with placebo (watch-and-wait) in patients with residual or recurrent grade 2 IDH-mutant glioma. However, reimbursement has not been recommended in several countries due to high cost and clinical uncertainty. This study aims to evaluate the cost-effectiveness of vorasidenib versus placebo for these patients from the perspective of Taiwan's National Health Insurance Administration (NHIA).
METHODS: A three-state Markov model comprising progression-free (PF), progressed disease (PD), and death states was developed over a 40-year horizon. Treatment effects of vorasidenib relative to the placebo were derived from the INDIGO trial, with hazard ratios applied to PF-to-PD transitions. Other transitions and direct medical costs were assumed to be identical between arms and were estimated from Taiwan NHI claims data to reflect local clinical practice. The vorasidenib medication costs were set at the international median price of the A10 reference countries. Other parameters were sourced from published literature. Cost-effectiveness was assessed using the incremental cost-effectiveness ratio (ICER) and incremental net monetary benefit (INMB), with a willingness-to-pay (WTP) threshold set at three times gross domestic product per capita in 2024 (NT$3,273,582). Quality-adjusted life-years (QALYs) and costs were discounted at 3% annually. Uncertainty was explored through deterministic (DSA) and probabilistic sensitivity analyses (PSA).
RESULTS: Compared with placebo, vorasidenib increased QALYs by 1.8922 and costs by NT$9,031,323, yielding an ICER of NT$4,772,826 per QALY, and an INMB of NT$
-2,837,051. DSA results revealed that the PF-to-death transition parameter and vorasidenib medication costs were the most influential. PSA results demonstrated that the probability of vorasidenib being cost-effective was approximately 26%.
CONCLUSIONS: Under current pricing and model assumptions, vorasidenib is unlikely to be cost-effective in Taiwan. Decision uncertainty remains substantial, highlighting the need for price reduction and additional long-term effectiveness evidence.
METHODS: A three-state Markov model comprising progression-free (PF), progressed disease (PD), and death states was developed over a 40-year horizon. Treatment effects of vorasidenib relative to the placebo were derived from the INDIGO trial, with hazard ratios applied to PF-to-PD transitions. Other transitions and direct medical costs were assumed to be identical between arms and were estimated from Taiwan NHI claims data to reflect local clinical practice. The vorasidenib medication costs were set at the international median price of the A10 reference countries. Other parameters were sourced from published literature. Cost-effectiveness was assessed using the incremental cost-effectiveness ratio (ICER) and incremental net monetary benefit (INMB), with a willingness-to-pay (WTP) threshold set at three times gross domestic product per capita in 2024 (NT$3,273,582). Quality-adjusted life-years (QALYs) and costs were discounted at 3% annually. Uncertainty was explored through deterministic (DSA) and probabilistic sensitivity analyses (PSA).
RESULTS: Compared with placebo, vorasidenib increased QALYs by 1.8922 and costs by NT$9,031,323, yielding an ICER of NT$4,772,826 per QALY, and an INMB of NT$
-2,837,051. DSA results revealed that the PF-to-death transition parameter and vorasidenib medication costs were the most influential. PSA results demonstrated that the probability of vorasidenib being cost-effective was approximately 26%.
CONCLUSIONS: Under current pricing and model assumptions, vorasidenib is unlikely to be cost-effective in Taiwan. Decision uncertainty remains substantial, highlighting the need for price reduction and additional long-term effectiveness evidence.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EE89
Topic
Economic Evaluation, Health Technology Assessment
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, Oncology