New Alzheimer’s drug slows cognitive decline by a third

Lilly’s Donanemab significantly slowed cognitive and functional decline in Phase 3 study of early Alzheimer’s disease.

Alzheimer’s disease is a devastating neurodegenerative disorder that affects millions of people worldwide, and which is characterized by the progressive decline of cognitive and functional abilities that leads to a loss of independence and quality of life.

Until recently, there hadn’t been a new drug approved for Alzheimer’s in 20 years leaving patients and their families with few options for managing the disease; now, however, there are three FDA-approved drugs available and a further 141 undergoing clinical trials [1].

One of those three is Eli Lilly’s Donanemab, and yesterday, the company announced results of its Phase 3 trial of the experimental drug that is designed to target and eliminate the amyloid beta plaques in the brain that are believed to be a key contributor to the neurodegeneration observed in Alzheimer’s disease sufferers. Previous studies have shown that reducing amyloid beta levels can slow or even halt cognitive decline in people with Alzheimer’s.

The latest study, which included 1,734 patients with early-stage Alzheimer’s, found that Donanemab significantly slowed cognitive and functional decline compared with placebo [2].

Longevity.Technology: Alzheimer’s disease is a major public health challenge worldwide. According to the World Health Organization, there are currently around 50 million people living with dementia, and this number is expected to triple by 2050. Alzheimer’s disease is the most common form of dementia, accounting for up to 70% of all cases, and its impact is not just limited to individuals living with the disease, but also affects their families and caregivers, as well as healthcare systems and economies. As the population ages and the number of people living with Alzheimer’s continues to grow, the need for effective treatments becomes more urgent. This study found that the drug significantly slowed cognitive and functional decline in patients with early-stage Alzheimer’s, providing hope for those living with this devastating condition.

While there is still much work to be done in developing safe and effective treatments for Alzheimer’s, the recent developments in the field are cause for hope and optimism; however, the success of drugs like these rely on early detection, diagnosis and treatment, and we should also be mindful of the cost – at over $26,000 per person per year, it’s not the easy win some headlines are proclaiming.

The drug was given as a monthly infusion until the distinctive amyloid plaques in the brain had gone. The researchers found that the pace of Alzheimer’s was slowed by about 29% overall, and in a set of patients that researchers thought would be more likely to respond, the slowing of clinical and functional decline was 35%.

The researchers noted that those trial participants receiving the drug better retained the ability to manage finances, drive, engage in hobbies, and converse about current events.

“We are thrilled with the results of this study, which demonstrate the potential of Donanemab to make a meaningful difference in the lives of people with early-stage Alzheimer’s,” said Daniel Skovronsky, MD, PhD, Lilly’s chief scientific officer and president of Lilly Research Laboratories.

“These findings represent a major step forward in the fight against Alzheimer’s and give us hope that effective treatments for this devastating disease are within reach [2].”

The Phase 3 trial of Donanemab is the latest in a series of promising developments in Alzheimer’s research. In recent years, there have been several other drugs that have shown promise in clinical trials, including aducanumab, which was approved by the FDA in 2021, and lecanemab, which is currently in Phase 3 trials.

Despite these promising developments, there are still significant challenges in developing effective treatments for Alzheimer’s. One major issue is the potential for side effects, particularly brain swelling, which has been observed in a small number of patients taking Donanemab and other amyloid beta-targeting drugs. Eli Lilly reported two deaths due to brain swelling in the Phase 3 trial of Donanemab, though it is important to note that the overall incidence of brain swelling was low and was carefully-monitored throughout the trial.

“As with any new treatment, there are potential risks and side effects that need to be carefully monitored and managed,” said Skovronsky. “However, the benefits of Donanemab in slowing cognitive and functional decline in people with early-stage Alzheimer’s are significant, and we believe that the potential benefits outweigh the risks [2].”

The ultimate goal in addressing Alzheimer’s and other age-related diseases is to improve healthspan and increase the number of years of healthy living. In addition to developing new treatments, there is also growing interest in approaches that focus on prevention and delaying the onset of Alzheimer’s. Lifestyle factors such as diet, exercise, and social engagement have been shown to play a role in reducing the risk of cognitive decline and dementia; advances in genetics and biomarkers may also help identify people at risk of developing Alzheimer’s, allowing for earlier intervention and treatment.


Photograph: kjpargeter/Freepik