Novo's GLP-1 liraglutide may protect brain from Alzheimer's, new study finds

An old GLP-1 that has since been outshined by Ozempic may have a new path to the limelight. In a small phase 2 trial of patients with mild Alzheimer’s disease, Novo Nordisk’s liraglutide slashed cognitive decline by 18%.

The trial failed to meet its primary endpoint—change in the metabolic rate of glucose in certain parts of the brain—but met secondary endpoints of slower loss of brain volume and slower cognitive decline. The results were presented at the Alzheimer’s Association International Conference on July 30.

The study enrolled 204 patients from 24 clinics across the U.K. Patients received a daily liraglutide injection for a year. Brain volume was analyzed using MRIs, glucose metabolism with PET scans, and cognition with a slew of 18 different tests of memory, comprehension, language and spatial orientation.

MRIs revealed that liraglutide reduced the loss of volume of certain brain regions by nearly 50%, according to a release. These regions include the frontal, temporal and parietal lobes, as well as total gray matter. This reduction in brain loss went along with an 18% slower rate of cognitive decline, as measured by a composite score of the 18 tests, which was significantly different from those who received placebo.

“The slower loss of brain volume suggests liraglutide protects the brain, much like statins protect the heart,” trial lead Paul Edison, M.D., Ph.D., a professor at Imperial College London, said in the release.

Similar to other GLP-1s, the most common side effects reported were gastrointestinal issues like nausea. Of patients receiving treatment, 6.9% experienced serious side effects, though most events were unlikely to be connected to liraglutide, according to Edison.

Liraglutide is branded as Saxenda for weight loss and Victoza for diabetes. Novo Nordisk announced last November that it was cutting supplies of Victoza to make room on the production line for its other weight loss GLP-1, the hugely popular Ozempic (semaglutide).

Ozempic may still ultimately get the last laugh over liraglutide, as it too has shown potential as a treatment for Alzheimer’s-related cognitive declines in a retrospective study. Novo is currently running a three-year trial of semaglutide in more than 1,800 Alzheimer’s patients called EVOKE Plus, with results set to read out in 2026.