Montreal researchers test drug to delay Alzheimer's in people at high risk

Montreal researchers are enrolling people in a Phase 3 international clinical trial testing whether a drug can delay the onset of Alzheimer's disease in people who show biological signs of the disease but haven't yet developed memory or cognitive decline.

The trial will screen roughly 150 to 200 people in the Montreal area to identify eligible participants — those ages 55 to 80 with unusually high levels of biomarkers linked to Alzheimer's who are at high risk of developing symptoms within the next few years. Half of all participants globally will receive the treatment; the other half will get a placebo. Researchers will track both groups over several years to see whether fewer people receiving the drug develop mild cognitive impairment.

Participants will receive an infusion once monthly for six months, then one every six months for several years. The full study could last four to five years. About 1,600 people are being recruited worldwide.

Dr. Simon Ducharme, a neuropsychiatrist at Douglas Mental Health University Institute, said the goal is to intervene before the disease reaches a stage where symptoms appear. "Once you start seeing doctors with symptoms, you've already stepped foot in a cascade that will be progressive," Ducharme said. "It's always better if we can prevent something, than trying to play catch up once the symptoms have started."

Two medications in the same general class were approved by Health Canada in 2026 for people already experiencing symptoms and can slow the progression of Alzheimer's disease. This trial targets an earlier stage — before symptoms emerge at all.