Alzheimers Dementia Int | Volume 1, Issue 1 | Letter to Editor | Open Access
Donald Berry
Founder & Senior Statistical Scientist Berry Consultants, LLC, USA
*Correspondance to: Donald Berry
Fulltext PDFWe read the article by Teipel, et al. with concern. It claims evidence of sex specific differences in the efficacy of lecanemab based on a Bayesian reanalysis of subgroup data from two phase 3 trials. Although framed as a methodological refinement, the analysis reflects a biased and fatally flawed interpretation of subgroup results. Readers will be misled regarding the strength and credibility of the underlying evidence. Neither Clarity AD nor Trailblazer ALZ2 was designed or powered to assess treatment by sex interactions. Subgroup analyses by sex were exploratory, and subject to the vagaries of post-hockery and multiplicity. The primary analyses in both trials demonstrated statistically persuasive efficacy in the overall populations. In this context, any inference of differential efficacy by sex must meet a high evidentiary bar, including strong biological plausibility and independent replication. These criteria were not satisfied in the lecanemab and donanemab trials.
Berry DA. Sex Differences in Treatment Effects of Lecanemab and Donanemab: A Bayesian Reanalysis of CLARITY AD and TRAILBLAZER-ALZ 2. Alzhimers Dementia Int. 2026; 1(1): 1004.