Study suggests that an older GLP-1 drug from Novo Nordisk can slow Alzheimer's disease progression by protecting the brain.

• Liraglutide, an older drug used daily for diabetes and obesity, may slow Alzheimer's disease progression by protecting the brain, as shown in a mid-stage trial.
• Sales of liraglutide, marketed as Saxenda and Victoza, are decreasing while demand for Ozempic and Wegovy, both weekly injections, is surging at Novo Nordisk.
• The growing body of evidence suggests that GLP-1 medications, widely used for weight loss and blood sugar regulation, may have additional health benefits.

A mid-stage trial released on Tuesday suggests that liraglutide, an older drug used daily for diabetes and obesity, may slow the progression of Alzheimer's disease by protecting patients' brains.

Liraglutide, sold as Victoza and Saxenda by Novo Nordisk, has been experiencing declining quarterly sales as patients opt for the company's weekly injections, Ozempic and Wegovy, for diabetes and weight loss, respectively.

Novo Nordisk and rival have been studying the potential of GLP-1s in patients with chronic conditions such as fatty liver disease and sleep apnea, in addition to their well-established benefits in promoting weight loss and regulating blood sugar.

In the UK, more than 200 patients with mild to moderate Alzheimer's were followed by researchers from Imperial College London. These patients were randomly assigned to receive either a daily injection of liraglutide or a placebo. The study was partially funded by Novo Nordisk.

After one year of treatment, patients who received liraglutide had a slower decline in cognitive function by 18% compared to those who received the placebo.

The phase two trial demonstrated that liraglutide slowed the shrinking of critical brain regions responsible for memory, decision-making, learning, and language by approximately 50% compared to the placebo, as determined by MRI scans. Alzheimer's disease is known to cause brain shrinkage as the disease progresses due to the breakdown and malfunction of crucial nerve cells.

The Alzheimer's Association International Conference in Philadelphia, the world's largest meeting for dementia research, saw the presentation of researchers' findings on Tuesday.

The Alzheimer's Association's vice president, Dr. Heather Snyder, stated that the new data highlights the variety of therapies being developed or tested for Alzheimer's disease, which is opening up the possibility of more personalized treatments for the condition.

The Alzheimer's Association reports that nearly 7 million Americans have the condition, making it the fifth-leading cause of death for adults over 65. By 2050, the number of Alzheimer's patients in the U.S. is projected to increase to almost 13 million.

Over the past year, the Alzheimer's treatment industry experienced a significant breakthrough, with two new drugs, Kisunla from Eli Lilly and Leqembi from Eisai, proven to slow disease progression by targeting a toxic protein in the brain called amyloid, a hallmark of the condition.

On Tuesday, Snyder informed CNBC that the new data provides an opportunity for scientists to investigate combining amyloid-targeting drugs with GLP-1s like liraglutide.

Research indicates that GLP-1s do not pose the risk of brain swelling and bleeding, which are side effects associated with Leqembi and Kisunla. Patients undergoing treatment with these amyloid-targeting drugs undergo routine MRIs to monitor for these side effects.

During the mid-stage trial, patients who received liraglutide most frequently experienced gastrointestinal side effects that are commonly associated with other GLP-1s, including nausea.

One advantage of using GLP-1s to treat Alzheimer's patients is that only a small percentage of those receiving amyloid-targeting drugs are currently using them.

Dr. Paul Edison, professor of neuroscience at the Imperial College London and the trial's lead author, stated to CNBC that the drug's safety profile is excellent and it has the potential to be widely used, which will significantly impact the field.

If GLP-1s are approved for Alzheimer's, they could be administered anywhere in the world with minimal monitoring, indicating a significant potential for those drugs.

But more research is needed, he noted.

Edison is participating in Novo Nordisk's phase three "EVOKE" and "EVOKE+" trials, which are investigating semaglutide, the active ingredient in Wegovy and Ozempic, in nearly 2,000 Alzheimer's patients.

Novo Nordisk has stated that it supports independent research on the use of GLP-1s as treatments for other conditions, but emphasized that these products are not currently approved for the treatment of Alzheimer's disease.

Liraglutide trial details

The primary objectives of the research were not to assess cognitive abilities or brain size.

The trial aimed to measure the brain's glucose consumption, which is crucial for evaluating cognitive function. As Alzheimer's disease advances, the glucose metabolic rate in specific brain regions decreases.

Edison and his team believed that they did not have enough participants in the trial to show a significant change in the rate. However, they found it encouraging that liraglutide met the study's second goal of improving cognitive function, as well as another goal of altering brain volume.

Edison observed that GLP-1s, including liraglutide, can safeguard the brain based on research findings.

He told CNBC that he believes showing cognitive improvement is crucial because that's what patients are concerned about.

Liraglutide likely achieves its effects by reducing inflammation in the brain, improving communication between nerve cells, lowering insulin resistance, and reducing two hallmarks of Alzheimer's disease: amyloid plaque and tau.

More research is needed to confirm that, Edison said.