Weight-loss drug ‘could slow progression of Alzheimer’s disease’

A diabetes and weight-loss medicine could help slow the progression of Alzheimer’s disease, according to a new study,

Liraglutide, taken as an injection once a day, is used to help people lose weight and can also be prescribed for diabetes.

New research has suggested that the drug, sold under the brand Saxenda, may bring further “neuroprotective” benefits.

The trial, which has been presented to the Alzheimer’s Association International Conference in the US, suggests that liraglutide can reduce shrinking in the parts of the brain that control memory, learning, language and decision-making by nearly half after a year of treatment compared to a dummy drug, also known as a placebo.

Researchers, led by experts from Imperial College London, said that after 12 months of treatment, the drug appeared to reduce cognitive decline by as much as 18%.

Some 204 patients with mild Alzheimer’s disease from across the UK were involved in the study.

All of the people who took part were given a daily injection – half received a placebo and half were given 1.8mg of liraglutide, which is manufactured by Novo Nordisk.

They received a number of examinations – including brain scans and memory tests – at the start of the study and again a year later.

Those who received liraglutide had nearly 50% less volume loss in several areas of the brain which are often affected by Alzheimer’s disease, including areas involved in memory, language and decision-making.

Cognitive tests examining memory, comprehension, language and spatial orientation revealed that those who took the drug had a “statistically significant slowing of cognitive decline” after a year compared to those who had the placebo drug.

Experts have called for larger studies to confirm the findings.

Study lead Paul Edison, professor of science at Imperial College London, said: “The slower loss of brain volume suggests liraglutide protects the brain, much like statins protect the heart.

“While further research is needed, liraglutide may work through various mechanisms, such as reducing inflammation in the brain, lowering insulin resistance and the toxic effects of Alzheimer’s biomarkers amyloid-beta and tau, and improving how the brain’s nerve cells communicate.”

Alzheimer’s Association chief science officer Maria Carrillo added: “We are in an era of unprecedented promise, with new treatments in various stages of development that slow or may possibly prevent cognitive decline due to Alzheimer’s disease.

“This research provides hope that more options for changing the course of the disease are on the horizon.”

The drug is known as a GLP-1 receptor agonist and works by mimicking the GLP-1 hormone, which is involved in regulating blood sugar levels. It enhances insulin secretion in response to food, reduces the amount of glucose, or sugar, produced by the liver and slows down how quickly food is digested.

Earlier this year, manufacturers warned over supply constraints due to a rise in demand for obesity treatments.

Commenting on the study, Dr Sheona Scales, director of research at Alzheimer’s Research UK, said: “Developing drugs for diseases like Alzheimer’s is costly, and can take many years.

“Being able to repurpose drugs already licensed for other health conditions could help accelerate progress and open up new avenues to prevent or treat dementia-causing diseases, such as Alzhiemer’s.

“This new research shows that people with early-stage Alzheimer’s taking liraglutide had a slower decline in memory and thinking, and less brain shrinkage, over 12 months, compared to placebo.

“However, the study was carried out in a small group of people. Larger trials are now happening to see whether drugs like liraglutide are effective at slowing down the progression of Alzheimer’s disease. What remains unknown is the ‘how’, and more research into the mechanism behind liraglutide and its protective effect against dementia is needed.”

Dr Richard Oakley, associate director of research and innovation at Alzheimer’s Society, added: “Research will beat dementia and drugs licensed for other conditions now make up 32% of the drugs in trials for Alzheimer’s disease around the world.

“This could save years and billions of pounds as repurposed drugs have already been shown to be safe and approved for use, so we only have to show the effect they have on Alzheimer’s disease.

“Alzheimer’s Society proudly funded the expansion of this trial from just 22 people to over 200 people with early-stage Alzheimer’s disease. We’re encouraged by the positive indications from this study that liraglutide may impact memory and thinking skills and potentially protect against brain shrinkage.

“Larger clinical trials are currently testing other compounds from this family of drugs and we look forward to seeing the results.

“More people receiving an early and accurate diagnosis is going to be vital in the future for identifying people who are most likely to benefit from new Alzheimer’s treatments, which are now finally within reach.”