A promising new experimental drug might just have the potential to prevent Alzheimer’s in individuals with a higher risk of developing the disease. This discovery comes from a study conducted by the Washington University School of Medicine in St. Louis. Researchers focused on people carrying rare genetic mutations that nearly “guarantee” the onset of Alzheimer’s.
The study involved 73 participants, all in their 30s, 40s, and 50s, who have the mutation that triggers an overproduction of amyloid in the brain. Amyloid is a protein that accumulates in the brain and can interfere with cognitive abilities, marking it as a key factor in Alzheimer’s. Participants had a family history of Alzheimer’s, experienced no or only mild cognitive decline, and were within a 15-year window of expected symptom development.
The trial tested a drug called gantenerumab, and for 22 participants who took it over eight years, the risk of developing symptoms was reduced by half, from 100% down to 50%. Dr. Randall J. Bateman, a senior author of the study, mentioned that there was no significant effect for those treated for only two to three years. These findings were published in The Lancet Neurology.
Gantenerumab is a monoclonal antibody that targets and removes amyloid plaques in the brain. Initially developed by Roche in Switzerland and its U.S. partner Genentech, the development was halted in 2023. This decision followed clinical trials that revealed the drug did not meet the “primary endpoint” for slowing cognitive decline in those with early symptomatic Alzheimer’s.
Dr. Bateman explained that every study participant was fated to develop Alzheimer’s, yet some have not shown symptoms. While the timeline for remaining symptom-free is uncertain, continuous treatment with another anti-amyloid antibody is ongoing to prevent symptom development. The aim is that, if successful, these prevention methods could be extended to the wider population.
Dr. Howard Fillit, co-founder of the Alzheimer’s Drug Discovery Foundation, highlighted the significance of this research. It shows that early treatment to clear plaques before symptoms appear can delay Alzheimer’s onset, similar to prevention strategies for other chronic diseases. Although gantenerumab is no longer under development, other drugs like remternetug by Eli Lilly are being evaluated for Alzheimer’s prevention.
Potential limitations and risks were acknowledged by Dr. Bateman, who pointed out the small sample size due to the rarity of Alzheimer’s caused by mutations. Moreover, anti-amyloid medications like gantenerumab have been linked to amyloid-related imaging abnormalities (ARIA), which appear on brain scans as “tiny spots of blood” or swelling. While most side effects resolve on their own, ARIA can occasionally lead to serious medical issues.
In this study, 30% of participants experienced ARIA, likely from the higher doses administered. Despite this, there were no life-threatening events or deaths, and the overall safety profile was consistent with previous trials. Dr. Chris Vercammen, a specialist in geriatrics, emphasized the need for more research, especially involving diverse populations and late-onset Alzheimer’s cases.
Dr. Fillit also noted that this research paves the way for further exploration of treatments for preclinical Alzheimer’s. As experts continue to study the long-term data and conduct additional research, the hope is that these efforts are bringing us closer to viable prevention options for those at risk of Alzheimer’s.
