A breakthrough weight loss injection, Liraglutide, sold under the brand name Saxenda, which is already prescribed to thousands of NHS patients, shows promising research suggesting it could significantly reduce the risk of developing Alzheimer's disease. This once-a-day injectable medication, belonging to a class known as GLP-1 agonists, is typically offered to individuals with a BMI over 30 to improve blood sugar control and assist with weight loss. It functions similarly to semaglutide, the active ingredient in Ozempic and Wegovy, by modulating the body's metabolism to induce feelings of fullness and reduce hunger.

Leading British experts now suggest that Liraglutide could also effectively slow cognitive decline and brain cell loss in Alzheimer's patients by as much as 50 percent. Researchers from Imperial College London, led by neuroscience expert Professor Paul Edison, stated that these findings represent "some of the strongest evidence to date" that weight loss jabs might aid in managing the condition, potentially paving the way for innovative dementia treatments. This revelation stands in contrast to recent trial results for semaglutide, which failed to demonstrate a statistically significant benefit in slowing the progression of Alzheimer's disease, leading to a 12 percent drop in the share value of its manufacturer, Novo Nordisk.

Professor Edison emphasized the significance of their findings, noting, "Our findings provide some of the strongest evidence yet that GLP-1 treatments could modify the disease process in Alzheimer's disease." He added that Liraglutide has shown encouraging effects on brain structure and the rate of cognitive decline in their Phase 2b trial, setting the stage for a comprehensive Phase 3 program. A major advantage highlighted by Professor Edison is the ability to repurpose an existing drug with established safety data, which could significantly accelerate its adoption for Alzheimer's compared to developing an entirely new therapy. Furthermore, he noted the importance of this trial in testing a distinct therapeutic approach for Alzheimer's disease, one that does not exclusively rely on amyloid-targeting strategies.

The Phase 2b study involved 169 individuals, with an average age of 71, diagnosed with mild to moderate Alzheimer's disease. Participants were divided into two groups: 72 received Liraglutide, while the remaining 82 were administered a placebo. Over a one-year follow-up period, brain scans revealed that Liraglutide effectively slowed brain volume loss by approximately half when compared to patients receiving the placebo. Additionally, it demonstrated an 18 percent more beneficial effect on cognition than the placebo. However, the researchers observed that Liraglutide did not prevent the decline of brain glucose metabolism.

While the exact mechanism for Liraglutide's effects on brain volume and cognition was not definitively stated, researchers noted that previous studies have indicated its capacity to reduce neuroinflammation and the accumulation of tau protein in the brain. Significant aggregations of tau protein, along with amyloid, are known to form plaques and tangles that are widely believed to underpin the symptoms of Alzheimer's, the foremost cause of dementia. Publishing their findings in the journal Nature Medicine, the scientists acknowledged the 12-month duration of the study as a limitation for definitively establishing long-term clinical benefits in Alzheimer’s disease, while affirming that it still yielded meaningful insights and that further research is essential to fully confirm the drug’s effectiveness.

Saxenda is currently available on the NHS as a treatment for weight loss, typically prescribed after a general practitioner refers a patient to a specialist weight management service. Common side effects include aches and pains, diarrhea, fever, frequent urination, and difficulty sleeping. Trials for Saxenda have shown that users lose an average of 6.4 percent of their body weight over 68 weeks. Dementia affects approximately 944,000 people in the UK and is estimated to impact around 7 million in the US, with Alzheimer's accounting for about six out of ten dementia cases. Early symptoms often include memory issues, difficulties with thinking and reasoning, and language problems, which progressively worsen over time.

Dr. Richard Oakley, Associate Director of Research and Innovation at Alzheimer’s Society, expressed satisfaction with having co-funded the ELAD trial, acknowledging its interesting insights into Liraglutide’s potential. However, he drew attention to the contrasting results from a larger Phase 3 trial of semaglutide, another GLP-1 drug, which did not show reduced cognitive decline in individuals with early Alzheimer’s disease. Dr. Oakley emphasized the critical need to investigate whether these drugs show promise in individuals at risk of Alzheimer's before symptoms manifest. He concluded by reiterating the Alzheimer’s Society’s commitment to supporting cutting-edge research, such as the ELAD trial, to drive change for everyone impacted by dementia, noting that one in three people will eventually develop dementia in their lifetime. Dementia was reported as the UK's leading cause of death in 2022, with 74,261 fatalities, an increase from 69,178 the previous year.