Experimental drug may prevent Alzheimer’s disease

Promising early data. Alzheimer’s disease (AD) researchers have long searched for a preventive therapy. A recent report brings new hope: an experimental anti-amyloid antibody showed it could delay the onset of Alzheimer’s symptoms in genetically at-risk individuals. In a trial of 73 people who carry aggressive Alzheimer’s mutations (and thus almost all get early dementia), those who took the drug for many years were much less likely to develop symptoms.

• Key result: Among participants treated the longest (an average of ~8 years), only ~50% had developed Alzheimer’s symptoms by midlife, whereas essentially all untreated mutation carriers would be expected to be demented by that age medicine.washu.edu. In other words, the drug cut the risk (or delayed onset) by about half in these high-risk people.
• What it means: As the lead investigator Bateman commented, “we know it’s possible at least to delay the onset of symptoms by years, or potentially decades” sciencedaily.com. For these patients “destined to develop Alzheimer’s,” giving extra decades of healthy cognition could be life-changing.

The drug being tested (an anti-amyloid antibody similar to donanemab or lecanemab) works by clearing amyloid plaques in the brain. This trial suggests that if started early, anti-amyloid therapy might prevent or substantially postpone Alzheimer’s dementia in people who carry these mutations. It is the first clinical evidence in humans that Alzheimer’s might be preventable with medication.

Caveats and next steps. These results are preliminary and limited to familial Alzheimer’s cases. It’s not yet clear if the same prevention would work for the more common late-onset AD. Also, antibody treatments can have side effects (like brain inflammation) and require years of IV infusions. More studies are needed, but this news revives hope. As researcher Randall Bateman put it, continuing treatment is being done “in hopes that these people will never develop symptoms” sciencedaily.com.

Looking forward. Based on these findings, larger trials are planned. If this approach pans out, it would mark a huge shift: from managing Alzheimer’s after diagnosis to warding it off. Some experts compare it to cholesterol drugs preventing heart attacks – catching disease before it strikes. The optimistic takeaway is that preventing Alzheimer’s may be possible, especially if therapies are given very early. For now, researchers urge watching ongoing trial results closely.