Alzheimer's drug efficacy varies significantly by sex
The newest drugs for Alzheimer's disease may help patients stay independent longer, but results suggest they might affect men and women differently. A recent analysis indicates that women may not respond as well as men to these drugs. In an 18-month clinical trial, the drug lecanemab slowed cognitive decline by up to 27 percent compared to a placebo. This promising finding led the FDA to approve lecanemab as a treatment for Alzheimer's in 2023. However, the analysis showed that men experienced a 43 percent slowing of cognitive decline, while women only showed a non-significant 12 percent improvement. Researchers from Canada and Italy conducted simulations based on the trial data. They found that the difference observed between men and women was rare, occurring only in 12 out of 10,000 simulations. Still, the reasons behind the 31 percent gap in effectiveness are not clear, prompting scientists to call for more research. About two-thirds of Alzheimer's patients are women. Therefore, these results raise concerns about the effectiveness of lecanemab for female patients. Experts argue that clinical trials should prioritize understanding how sex affects drug responses. Lecanemab works by targeting amyloid plaques in the brain, which have been linked to Alzheimer's. However, the exact way the drug influences cognitive decline is still unclear. Some studies suggest that the presence of amyloid plaques is not always a reliable indicator of the disease. Moreover, biological differences between sexes, including hormones and chromosomes, might affect how the brain handles these plaques. Researchers are urging the sharing of clinical trial data to explore these differences further. Despite the increasing recognition of sex differences in brain health, most research has not focused on this aspect. Experts warn that the ongoing male bias in neuroscience could harm female health. Understanding these differences is vital for improving treatment and care for both men and women with Alzheimer's disease.