Experts say the trial provides further evidence that tackling protein buildup in the brain can slow disease progression.
An experimental Alzheimer’s disease drug has been shown to significantly slow disease-related cognitive and functional decline with results hailed as “remarkable” by experts, despite serious side effects in some patients.
US pharmaceutical giant Eli Lilly announced on Wednesday that in a late-stage trial of nearly 1,200 people in the early stages of Alzheimer’s disease, the drug, donanemab, slowed the progression of symptoms by 35% over a period 18 months versus placebo.
The effect was measured by the patients’ cognition and ability to perform daily tasks such as managing finances, driving, hobbies and talking about current events in a standardized index called the Health Rating Scale. Integrated Alzheimer’s disease (iADRS).
Side effects included temporary swelling in parts of the brain, which occurred in almost a quarter of treated patients.
Lilly said the incidence of severe brain swelling in the study was 1.6%, with two deaths attributed to the disease, while a third may also have died from the treatment.
Nonetheless, the data was widely welcomed by independent experts, who said donanemab has the potential, if it gains regulatory approval, to significantly improve the lives of people with the most common form of dementia.
Lilly said it was “extremely pleased” with the study results and would submit its findings to the US Food and Drug Administration (FDA) as well as other global regulators and hoped to get the US approval by the end of the year.
Mark Mintun, a senior Lilly executive in neuroscience R&D, however, acknowledged that “like many effective treatments for debilitating and life-threatening diseases, there are associated risks that can be serious and life-threatening.”
According to the World Health Organization (WHO), more than 55 million people worldwide live with dementia, posing a significant challenge to health systems. With the aging population, the UN health agency expects the number of people affected to reach 78 million by 2030 and 139 million by 2050.
In January, the United States approved lecanemab, an Alzheimer’s disease drug produced by Biogen and Eisai, which was shown to slow the rate of cognitive decline by 27% and which was also declared revolutionary by experts. .
Alzheimer’s disease is characterized by an accumulation of tau and beta-amyloid proteins, which form plaques and tangles causing brain cell death and brain shrinkage.
Like lecanemab, donanemab is an antibody therapy that targets beta-amyloid.
Patients in the late-stage trial had intermediate levels of tau.
“This clinical trial is a real breakthrough, demonstrating a remarkable 35% slowing of cognitive decline in Alzheimer’s disease patients with high beta-amyloid but low tau load,” said Marc Busche, group leader from the UK Dementia Research Institute at University College London.
Experts say treatments targeting the two proteins could be even more effective.
Alzheimer’s disease accounts for up to 80% of dementia cases, according to the Alzheimer’s Association. It gradually destroys thinking and memory, depriving people of the ability to perform the simplest tasks.
“This is the strongest phase 3 data for an Alzheimer’s treatment to date,” said Maria Carrillo, chief scientific officer of the US Alzheimer’s Association. “This further underscores the inflection point we find ourselves at for the field of Alzheimer’s disease.”