Supplementary file 1_Lifetime cost-effectiveness of lecanemab for early Alzheimer’s disease.docx

IntroductionLecanemab is the second anti-amyloid-β monoclonal antibody to receive FDA approval for the treatment of early Alzheimer’s disease (AD), following aducanumab. Unlike aducanumab, which faced restricted Medicare coverage, lecanemab received traditional approval in 2023, resulting in broader access through Medicare. Despite these developments, the comparative cost-effectiveness of lecanemab and aducanumab has not been fully established. This study aimed to assess whether lecanemab is more cost-effective than aducanumab in the management of early AD.
MethodsAn indirect comparison of cost-effectiveness was performed due to the absence of head-to-head randomized controlled trials. A five-state Markov model was constructed from the perspective of the US healthcare system with a lifetime horizon and a 1-year cycle length. Model outcomes included life-years (LYs), quality-adjusted life-years (QALYs), and costs, all discounted at an annual rate of 3%. Incremental cost-effectiveness ratios (ICERs) were calculated and compared with established willingness-to-pay (WTP) thresholds. One-way sensitivity analyses identified key drivers of model uncertainty, and a probabilistic sensitivity analysis (PSA) with 1,000 Monte Carlo simulations tested the robustness of the findings.
ResultsThe incremental cost of the lecanemab group compared to the aducanumab group was $30,018.97, with an increase in quality-adjusted life-years (QALYs) of 0.25, resulting in an ICER of $121,678.49 per QALY gained. The result of the one-way sensitivity analysis showed that the utility of the state of mild dementia due to AD had the most important effects on the ICER of the lecanemab group compared to the aducanumab group. The probabilistic sensitivity analysis showed that lecanemab was more cost-effective than aducanumab across various WTP thresholds.
ConclusionOur findings suggest that lecanemab provides greater value than aducanumab; however, at current list prices, neither drug is cost-effective compared with the standard of care. Price reductions are necessary to improve affordability, particularly for lecanemab, which is more widely covered by Medicare. Policy implications remain significant, as under the Inflation Reduction Act (IRA), biologics such as lecanemab are exempt from Medicare price negotiations for 13 years post-approval, limiting short-term opportunities for cost adjustment.