Two large-scale phase 3 trials found that semaglutide did not significantly slow cognitive decline in early-stage Alzheimer’s disease despite improving biomarkers.
The trials were global, involved nearly 3,800 adults (aged 55–85) with mild cognitive impairment or mild dementia, and compared oral semaglutide vs placebo over about two years.
While semaglutide remains important for diabetes and weight-management, this result highlights how difficult it is to find treatments that truly slow Alzheimer’s progression — and why biomarker shifts don’t always mean clinical benefit.
There was real excitement when Novo Nordisk announced two major late-stage trials testing semaglutide — an already-approved drug for type 2 diabetes and obesity — for early Alzheimer’s disease.
The idea: if semaglutide could help protect the brain, perhaps it could slow down the dementia-march that so many fear.
But the outcome? The drug didn’t deliver the hoped-for clinical benefit in these Alzheimer’s trials. While it showed improvement on certain biomarkers (the molecules and signals we associate with the disease), those didn’t translate into slower memory loss or cognitive decline.
“Based on the significant unmet need in Alzheimer’s disease, as well as a number of indicative data points, we felt we had a responsibility to explore semaglutide’s potential, despite a low likelihood of success. We are proud to have conducted two well-controlled phase 3 trials in Alzheimer’s disease that meet the highest standards of research and rigorous methodology,” Martin Holst Lange, chief scientific officer and executive vice president of Research and Development at Novo Nordisk, said in a statement.
“We sincerely thank all participants and their caregivers for their meaningful contributions. While semaglutide did not demonstrate efficacy in slowing the progression of Alzheimer’s disease, the extensive body of evidence supporting semaglutide continues to provide benefits for individuals with type 2 diabetes, obesity, and related comorbidities.”
What the studies found
The trials — named EVOKE and EVOKE+ — were rigorous: randomized, double-blind, placebo-controlled, each enrolling people aged 55–85 who had mild cognitive impairment or mild dementia due to Alzheimer’s, and confirmed amyloid positivity (a hallmark of Alzheimer’s disease).
The trials ran for 104 weeks (about two years) of main treatment, with an additional extension period planned. Semaglutide was given orally at the same dose used in the weight/diabetes setting (14 mg once daily).
Ultimately, the primary endpoint — change in the Clinical Dementia Rating–Sum of Boxes score (CDR-SB) from baseline to week 104 — did not show a statistically significant difference between semaglutide and placebo.
In short: despite shifting some Alzheimer’s-related biomarkers, the drug did not slow the disease in a meaningful way in real-world cognitive and functional measurements.
Importantly, the safety profile was consistent with what was already known for semaglutide across other patient populations — no new red flags emerged in this Alzheimer’s study.
Because of the lack of efficacy, Novo Nordisk said it will discontinue the one-year extension portion of the trials.
What this means
For consumers and patients, the take-home message is that even when a drug is already successful in other diseases (diabetes, obesity), repurposing it for Alzheimer’s is not guaranteed to work.
The biomarker improvements raised hope, but this result underscores how complex Alzheimer’s is — and how the brain’s response doesn’t always match expectations.