Sex differences in efficacy/safety of anti-amyloid-beta monoclonal antibodies for the treatment of Alzheimer's disease.

Alzheimer's disease (AD) is the most common cause of dementia. AD exhibits notable sex-related disparities in prevalence, progression, and treatment response. With the recent approval of anti-amyloid-beta monoclonal antibodies-aducanumab, lecanemab, and donanemab-understanding sex differences in their clinical effects has become increasingly relevant. This review article investigates sex differences in the pharmacokinetics, efficacy, and safety of aducanumab, lecanemab, and donanemab and discusses the possible mechanism underlying the observed differences. Although sex-specific analyses were largely underreported in clinical trials, population pharmacokinetic models identified sex as a covariate affecting clearance and volume of distribution for aducanumab and lecanemab and higher exposure to lecanemab was predicted for females. Subgroup analyses of phase 3 trials revealed that males tended to experience greater benefit from aducanumab and lecanemab, whereas females showed better response to donanemab. The overall incidence of adverse events, including amyloid-related imaging abnormalities, did not show significant differences between sexes. Potential mechanisms underlying these differences include sex-related variations in blood-brain barrier permeability, apolipoprotein E4-associated neuroinflammatory responses, and baseline disease characteristics. These findings underscore the need for future AD clinical trials to incorporate sex-based analyses and to consider sex as a key factor in optimizing treatment strategies.