A major international study will soon test whether an experimental Alzheimer's drug can delay — or even prevent — the disease before memory loss begins. If successful, researchers say the approach could transform Alzheimer's care by treating people at high risk years before symptoms appear.

The drug, called trontinemab, is being compared to the way statins are used to lower the risk of heart attacks and strokes before they occur. Early research suggests trontinemab can clear toxic amyloid plaques from the brain in as little as three months, according to The Telegraph. The new Phase III clinical trial will determine whether that translates into preventing or delaying dementia.

The study, known as PrevenTRON, will enroll about 1,600 cognitively healthy adults ages 55 to 80 from countries around the world, including the United Kingdom. Participants will have no memory problems but will test positive for elevated blood levels of p-tau217, a biomarker associated with Alzheimer's disease that identifies people at higher risk.

Scientists have described the trial as a potential "game changer," raising the possibility that one day people at increased risk for Alzheimer's could receive preventive treatment much as statins are prescribed to reduce the risk of cardiovascular disease.

Trontinemab, developed by Roche, is an investigational antibody that uses a technology called Brainshuttle, designed to help more of the drug cross the blood-brain barrier and reach amyloid plaques in the brain. The drug targets amyloid beta, the sticky protein that accumulates in Alzheimer's disease. Early studies have shown unusually rapid plaque clearance compared with earlier anti-amyloid therapies.

The key question the trial hopes to answer is whether removing amyloid before symptoms develop can delay — or even prevent — the onset of memory loss and other signs of Alzheimer's disease.

If the strategy succeeds, it could fundamentally change the way Alzheimer's is managed by shifting the focus from treating established disease to identifying people at risk through simple blood tests and intervening before brain damage causes noticeable symptoms.

Researchers caution, however, that removing amyloid plaques does not necessarily prevent dementia. Although early studies of trontinemab have shown encouraging biomarker results and relatively low rates of amyloid-related imaging abnormalities (ARIA), only the Phase III trial can determine whether those biological changes preserve memory, daily functioning, and independence.

The study also reflects a broader shift in Alzheimer's research toward detecting the disease earlier with blood tests rather than waiting for symptoms to appear. If successful, this approach could make prevention trials faster, less invasive, and more widely available outside major medical centers.

Dr. Maria Carrillo, chief science officer at the Alzheimer's Association, said: "This is the future of Alzheimer's care, targeting the earliest stages of the disease, including in its silent stage before memory issues arise.

"This is when treatments may have the greatest benefit – perhaps even keeping people from ever experiencing dementia symptoms."