A sibling of the popular diabetes and weight loss drug semaglutide may help slow the progression of Alzheimer’s. In clinical trial data published this week, British scientists found evidence that liraglutide can reduce brain atrophy and cognitive decline in patients with Alzheimer’s. Semaglutide is already being tested in a larger Phase 3 trial for the neurodegenerative disease.
Liraglutide and similar drugs mimic the hormone GLP-1, which regulates blood sugar and appetite. It was approved in 2010 to treat type 2 diabetes and in 2014 to treat obesity. People with poorly controlled diabetes are known to be at higher risk for Alzheimer’s and other dementias, but animal studies suggest that liraglutide may prevent brain damage that occurs in Alzheimer’s. Scientists at Imperial College London therefore decided to conduct a double-blind, randomized, placebo-controlled trial of liraglutide for Alzheimer’s disease.
The trial enrolled 204 patients diagnosed with early-stage Alzheimer’s disease, half of whom were given liraglutide. The drug did not appear to significantly change glucose metabolism in the brain, the study’s main outcome measure. But the researchers found that people who received liraglutide lost brain volume nearly 50% slower over the next year than people who received a placebo. They also found that people who received the drug experienced 18% slower decline in measured cognitive function over the same period. The team’s findings were presented this week at the Alzheimer’s Association International Conference.
The study is still preliminary and hasn’t gone through the peer-review process, and even if we assume the results are valid, it’s still not clear exactly how liraglutide might be improving people’s brains, but the researchers have some ideas for explanations.
“We think liraglutide may protect the brain by reducing inflammation, decreasing the toxic effects of insulin resistance and Alzheimer’s biomarkers, or improving the way nerve cells in the brain communicate,” Paul Edison, professor of neuroscience in Imperial College’s School of Brain Sciences and an investigator on the study, said in a university statement.
Perhaps what’s most interesting about this study is that since it began, more powerful GLP-1 drugs have emerged, such as semaglutide. Semaglutide (sold under the names Ozempic and Wegovy) and the even newer tirzepatide (Maunjaro and Zepbound) have proven significantly more effective at treating diabetes and obesity than older GLP-1 drugs such as liraglutide. And a study published last month has already found evidence that semaglutide can boost brain health in people with type 2 diabetes.
Novo Nordisk, the manufacturer of both liraglutide and semaglutide, is currently conducting two large, placebo-controlled trials to see whether semaglutide can improve the course of people diagnosed with early-stage Alzheimer’s. If these results, expected within the next few years, are positive, semaglutide and other GLP-1 drugs should become the latest tool in a growing arsenal of treatments for Alzheimer’s.
