Popular weight-loss drugs don’t tip the scales against Alzheimer’s

The blockbuster diabetes medication semaglutide has conquered pharmaceutical sales charts as a proven diet aid and a reducer of obesity-related cardiovascular risks. Could the wonder drug even slay Alzheimer’s disease?

No such luck. According to phase 3 trials sponsored by Novo Nordisk, the Danish company behind the semaglutide brands Ozempic and Wegovy, semaglutide alters Alzheimer’s biomarkers but doesn’t slow the disease’s advance. 

The findings come after a two-year analysis of semaglutide against Alzheimer’s progression in more than 3,800 patients aged 55 to 85 who began the study with early symptoms as well as biomarkers of the disease. 

The trials were randomized and double-blinded, and the researchers used a placebo control cohort of patients who received standard care. 

The hypothesis that semaglutide might be an effective intervention came from real-world evidence studies as well as preclinical models and post-hoc analyses from diabetes and obesity trials.

Study participants tolerated semaglutide well, suggesting safety consistent with the drug as tested for other indications—not to mention its use in more than 37 million patient-years for diabetes, weight loss and cardiovascular risk reduction. 

Alas, a confirmation of semaglutide’s good safety profile was the best news the investigation delivered.

“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,” Novo Nordisk chief science officer Martin Holst Lange comments in a company announcement. “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.”

Translation: Regarding semaglutide vs. Alzheimer’s, the science is settled. Semaglutide can’t win this one. 

The other major drugmaker with a semaglutide product on the market, Eli Lilly (tirzepatide, brand names Mounjaro and Zepbound), has not committed to testing—or to not testing—its meds against Alzheimer’s. 

The Alzheimer’s Association has issued a statement on the Novo Nordisk findings. 

“While these results are not what we had hoped for, they will contribute to our understanding of this devastating and fatal disease,” the group’s CEO, Joanne Pike, DrPH, says. “We remain optimistic about the future of Alzheimer’s treatment and prevention as the scientific landscape continues to diversify and expand.”