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SALT LAKE CITY — A class of drugs that's been hailed for weight loss and diabetes care also appears to protect the brain from Alzheimer's disease.
The drug liraglutide — in the same class as Ozempic and Zepbound — was found in a phase 2b clinical trial to nearly halve shrinkage in the parts of the brain that control learning, memory, language and decisionmaking, according to a clinical trial that compared it to a placebo.
The findings were presented this week at the Alzheimer's Association International Conference in Philadelphia.
Researchers also found that the patients receiving liraglutide who had mild Alzheimer's disease symptoms had 18% slower decline in cognitive function in a year compared to those who received a placebo.
A class that includes Ozempic, Wegovy
Liraglutide is a precursor to Ozempic and like the popular weight loss/diabetes management drug, it's a GLP-1 agonist. Liraglutide is prescribed for diabetes control, weight loss and to reduce risk of heart and kidney disease, as well as stroke.
GLP-1 receptor agonists imitate the hormone glucagon-like peptide, which the stomach releases after someone eats. Studies in animal models of Alzheimer's disease suggest the drugs protect the brain by reducing early forms of the amyloid plaque that builds up and is a hallmark of Alzheimer's disease. The drugs also seems to help the brain process glucose the way it's supposed to and aid memory and learning. According to the association's summary of the study, liraglutide probably works on the brain in multiple ways.
Alzheimer's breakthroughs
Interestingly, the study was first undertaken to see if the drugs harm the brain, but the opposite appears to be true.
"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," Maria C. Carrillo, chief science officer and medical affairs lead for the Alzheimer's Association, said in the release. "This research provides hope that more options for changing the course of the disease are on the horizon."
She added that "repurposing drugs already approved for other conditions" provides a shortcut in that much has already been learned about them, including some side effects.
The association said that its Part the Cloud grant program has invested more than $82 million into research, including helping to fund 68 clinical trails.
Liraglutide study details
This liraglutide trial, which involved 204 people diagnosed with mild Alzheimer's symptoms, was randomized, double-blinded and placebo-controlled. The study was led by Dr. Paul Edison, professor of science at Imperial College London and involved patients at 24 clinics throughout the United Kingdom who received a daily subcutaneous injection for a year.
They also had magnetic resonance imaging and positron emission tomography scans at the beginning and end of the study, as well as detailed memory testing at the beginning, middle and end of the trial.
The goal of the study was change in the brain's glucose metabolic rate in the hippocampus, medial temporal lobe and posterior cingulate. That goal was not met. But on the secondary goal of improved scores for clinical and cognitive measures and also brain volume, statistically significant improvement was seen.
"The slower loss of brain volume suggests liraglutide protects the brain, much like statins protect the heart," said Edison in the release. "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."
