Shares in Danish pharmaceutical company Novo Nordisk fell to a four-year low on November 24, 2025, after the company announced that trials of its weight loss drug, semaglutide, did not demonstrate the expected efficacy in slowing the progression of Alzheimer’s disease. The news caused the company’s market value to drop by 12 percent, reflecting investor disappointment over the failed trials.
Initially, Novo Nordisk aimed to repurpose semaglutide, the active ingredient in its popular weight loss injections Wegovy and Ozempic, as a potential treatment for dementia. Early studies had suggested promising results, leading the company to explore its effects on patients aged 55 to 85 suffering from mild cognitive impairment or mild dementia due to Alzheimer’s disease. In total, 3,808 participants were involved in the trials, split evenly between those receiving oral semaglutide and those given a placebo.
The findings revealed no statistically significant difference in Alzheimer’s disease progression between the two groups. Martin Holst Lange, Chief Scientific Officer and Executive Vice President of Research and Development at Novo Nordisk, acknowledged the disappointing results but emphasized the importance of exploring the drug’s potential, given the significant unmet medical need in Alzheimer’s care. He stated, “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.”
The implications of these results extend beyond just Novo Nordisk. Fiona Carragher, Chief Policy and Research Officer at the Alzheimer’s Society, expressed her disappointment, saying, “These eagerly awaited results are not what we hoped for. However, no trial is wasted. Every investigation helps us develop better drugs and design better trials in the future.” She noted that over 130 Alzheimer’s drugs are currently undergoing clinical trials, with around 30 in late-stage evaluations, the final step before regulatory consideration.
Carragher stressed the need for increased government investment in early diagnosis, highlighting that one in three individuals with dementia currently lack a diagnosis. She warned, “We must avoid a situation where regulators approve treatments but too many people don’t receive them because they don’t have an early and accurate diagnosis.”
In response to the trial’s outcome, Dr. Susan Kohlhaas, Executive Director of Research at Alzheimer’s Research UK, remarked, “Today’s disappointing results on semaglutide will come as a blow for people affected by Alzheimer’s. These trial results are another reminder that Alzheimer’s is driven by several different biological processes. No single approach is likely to be enough.”
Dr. Kohlhaas called for a renewed focus on understanding these complex processes and developing multifaceted treatments that address the disease from various angles. As the research community grapples with this setback, the emphasis remains on fostering innovation and exploration in the search for effective Alzheimer’s treatments.
Novo Nordisk’s experience serves as a reminder of the challenges faced in drug development, particularly for complex conditions like Alzheimer’s. The journey continues as researchers work to uncover new possibilities in the fight against this devastating disease.
