A new experimental drug for Alzheimer’s disease is being tested in a groundbreaking trial that aims to stop the condition from developing before symptoms appear. The study, called PrevenTRON, is being conducted by the Surrey and Borders Partnership NHS Foundation Trust as part of a global effort to prevent dementia. It will involve around 1,600 people aged 55 to 80 from across the world, including the first European participants who will be screened starting this week. The trial focuses on healthy individuals who are at higher risk of developing Alzheimer’s, based on a blood test that detects a protein called p-tau217, which is a known biomarker for cognitive decline and Alzheimer’s. The p-tau217 blood test is a significant advancement in early detection, as previous research has shown that people with high levels of this protein have a 78% chance of developing cognitive impairment within 10 years. Moreover, the test can identify Alzheimer’s with up to 95% accuracy. Participants will first be tested to ensure they have no existing memory problems before undergoing the p-tau217 test. Those who meet the criteria will be offered the experimental drug, trontinemab, developed by Swiss pharmaceutical company Roche. Trontinemab is designed to target amyloid plaques, a toxic protein that accumulates in the brain and damages brain cells, leading to Alzheimer’s. Early studies showed that the drug cleared these plaques in 90% of people with early-stage Alzheimer’s or mild cognitive impairment within 28 weeks. However, the PrevenTRON trial is not testing the drug on people already diagnosed with Alzheimer’s. Instead, it aims to determine whether trontinemab can prevent the onset of dementia in those at risk by stopping the disease before symptoms begin. Professor Ramin Nilforooshan, the chief investigator of the trial, emphasized the shift in focus from treating Alzheimer’s after symptoms appear to preventing it altogether. He noted that the trial is still experimental and that results are not yet known. “I’m not saying this trial is magic. It’s an investigational medicine. We need to wait and see: will it work or not?” he said. The trial is expected to last four to six years, with participants randomly assigned to receive either trontinemab or a placebo. At least 15 UK hospitals and clinics will be involved, with recruitment led by the Surrey and Borders Partnership trust. Those interested in participating can contact the research team for more information.