Circ J. 2026 Sep 29. doi: 10.1253/circj.CJ-26-0576. Online ahead of print.
ABSTRACT
BACKGROUND: Tafamidis improves survival in patients with transthyretin amyloid cardiomyopathy (ATTR-CM); however, its cost raises concerns regarding healthcare sustainability. We evaluated the stage-specific cost-effectiveness of tafamidis in Japan.
METHODS AND RESULTS: Individual patient-level data were reconstructed from published Kaplan-Meier curves from the ATTR-ACT long-term extension study. Time-dependent survival benefit between early (continuous tafamidis) and delayed (placebo-to-tafamidis) tafamidis initiation was quantified using restricted mean survival time (RMST). Stage-specific incremental cost-effectiveness ratios (ICERs) were estimated according to National Amyloidosis Centre (NAC) stage. Drug costs reflected the official Japanese reimbursement price, and quality-adjusted life years (QALYs) were derived from RMST gains. The primary endpoint was cardiovascular mortality. At maximum follow-up, RMST gains were 15.7, 13.1, and 1.2 months in NAC stage I, II, and III, respectively ICERs declined over time but remained above commonly accepted Japanese willingness-to-pay thresholds (5,000,000-15,000,000 yen/QALY). The lowest ICER was 47,000,000 yen/QALY in NAC stage I at 90 months. Sensitivity analyses showed that results were robust across utility assumptions, whereas drug cost was the principal determinant of cost-effectiveness.
CONCLUSIONS: The survival benefit and economic value of tafamidis varied by disease stage. Earlier-stage patients derived the greatest benefit and economic value; however, ICERs remained above Japanese willingness-to-pay thresholds across all NAC stages. Earlier diagnosis may maximize clinical benefit, but substantial price reduction is likely required for sustainable healthcare in ATTR-CM.
PMID:42816364 | DOI:10.1253/circj.CJ-26-0576