A major international clinical trial has been launched to determine whether an experimental drug can prevent Alzheimer’s disease before symptoms such as memory loss begin to appear in people at high risk.
The Phase III study, known as PrevenTRON, will enrol about 1,600 adults aged 55 to 80 who are cognitively healthy but have blood biomarkers associated with the early development of Alzheimer’s disease.
Participants will receive trontinemab, an investigational drug developed by Swiss pharmaceutical company Roche, to assess whether it can delay or prevent dementia by targeting the disease in its earliest stages.
Researchers say the trial marks a significant shift in Alzheimer’s treatment by focusing on prevention before irreversible brain damage occurs, rather than treating patients after symptoms develop.
The study was unveiled at the Alzheimer’s Association International Conference in London, where scientists described early intervention as one of the most promising approaches to tackling the disease.
Maria Carrillo, Chief Science Officer at the Alzheimer’s Association, said treating the disease before memory problems emerge could dramatically improve long-term outcomes.
“This is the future of Alzheimer’s care, targeting the earliest stages of the disease, including in its silent stage before memory issues arise,” she said.
“This is when treatments may have the greatest benefit — perhaps even keeping people from ever experiencing dementia symptoms.”
Trontinemab works by clearing amyloid plaques — protein deposits that accumulate in the brain and are strongly linked to Alzheimer’s disease. Early-stage studies suggest the drug can remove these plaques after about three monthly infusions, a faster response than existing approved amyloid-targeting treatments.
The trial also builds on advances in blood-based screening, particularly the use of the p-tau217 biomarker, which researchers say can identify people at risk years before cognitive decline becomes evident.
Data presented at the conference showed the blood test could detect Alzheimer’s disease with up to 95 per cent accuracy. Another study involving nearly 2,700 adults with no signs of cognitive impairment found that those with the highest levels of the biomarker had a 78 per cent chance of developing cognitive problems within the next decade.
Rachel Buckley, Associate Professor of Neurology at Harvard Medical School, said positive findings from the trial could transform the management of Alzheimer’s disease.
“If these trials are positive, the game changes,” she said.
Despite the optimism, scientists cautioned that larger studies are still needed to confirm whether removing amyloid plaques can significantly reduce the risk of dementia or meaningfully delay cognitive decline.