Researchers hope the drug will slow progression of Alzheimer’s (Image: Getty)
A dementia drug that could slow Alzheimer’s disease before symptoms develop is being tested in a major trial of around 1,600 people. The treatment works by removing toxic amyloid proteins from the brain and could be more effective than previous drugs. A study across 18 countries is recruiting people aged 55 and over who do not have cognitive symptoms but may be at high risk of Alzheimer’s disease.
Blood tests will be used to identify patients who are most likely to benefit. A smaller study found the drug cleared amyloid in the brain in nine out of 10 patients after 28 weeks. Experts who analysed data from 178 patients and 477 brain scans suggested those on the highest dose may be free of amyloid in as little as three months. Trontinemab is a next-generation dementia drug which could prove more effective than the first anti-amyloid medications proven to tackle the underlying cause of Alzheimer’s.
Two similar drugs — lecanemab and donanemab — are licensed in the UK but were rejected for NHS use because their benefits were judged too small to justify their cost.
Dr Rachel Buckley, associate professor of neurology at Harvard Medical School, said: “If these trials are positive, the game changes.”
Dr Emer MacSweeney is a consultant neuroradiologist and CEO at Re:Cognition Health, which is taking part in the trontinemab trial.
She said: “This is another hugely encouraging step forward in Alzheimer’s research and reflects the remarkable momentum we are now seeing in the development of disease-modifying treatments.”
Lecanemab and donanemab have “already begun to transform the lives of many patients with early Alzheimer’s disease by slowing progression and allowing people to maintain their independence for longer”, Prof MacSweeney said.
She added: “Every successful clinical trial moves us closer to a future where we can diagnose and intervene earlier, target multiple disease pathways, and offer patients more effective, personalised treatments.”
Dr Richard Oakley, associate director of research and innovation at Alzheimer’s Society, said: “These trontinemab trials are among the most anticipated and exciting developments we have seen in Alzheimer’s research for some time, and we look forward to the results.”
Trontinemab, made by Swiss pharmaceutical giant Roche, is administered in seven monthly infusions, followed by doses every three months. It combines a previously tested drug, gantenerumab, with a “shuttle” molecule that helps the antibody cross the blood-brain barrier more effectively.
Professor Rob Howard, an expert in old age psychiatry at UCL, said: “The anti-amyloid antibodies that have been used in the past, probably about 1% of what’s infused into the patient actually gets into the brain.
Blood tests will help researchers identify patients for the trial (Image: Getty)
“By linking one of the antibody molecules to a molecule of transferrin, you sort of trick the brain into taking it up and get more of the antibody into the brain, more quickly.”
Prof Howard said small studies had shown trontinemab seemed to remove amyloid “quite quickly” while causing fewer incidents of brain swelling and bleeding than previous drugs.
But he added: “What we don’t know yet is whether it has more of an effect on the actual Alzheimer’s disease process and the symptoms.
“No one has ever shown that you can actually reduce the number of people who move from having amyloid in their brains to having dementia with this treatment.
“It’s an interesting concept but until you’ve actually demonstrated that these drugs stop the emergence of dementia in people who were probably going to get it, we should be very careful about talking about ‘game-changers’.
“It could be a game-changer and breakthrough, but we haven’t got any real data yet.”
Hilary Evans-Newton, chief executive of Alzheimer’s Research UK, said larger trials were needed to show whether treatment resulted in meaningful benefits.
She added: “The first wave of anti-amyloid drugs has already shown that it is possible to change the course of Alzheimer’s, moving from managing symptoms to targeting the underlying disease.
“Now, the next generation of potential treatments is asking an even bigger question: can we intervene earlier, more effectively and, we hope, more safely, before memory and thinking are badly affected?
“That is why the idea of one day protecting brain health before symptoms take hold with a ‘statin for the brain’ is so powerful.”
