Overview

Alzheimer’s disease is the most common cause of dementia among older adults. It’s the fifth leading cause of death for adults aged 65 and older and the seventh leading cause of death for all adults. For decades, researchers have been looking for a cure for Alzheimer’s without much success — but there’s hope. An experimental drug made by pharmaceutical companies Biogen and Eisai has been shown to slow cognitive and functional decline in patients with early-stage Alzheimer’s, making it the first drug to treat Alzheimer’s symptoms effectively ever.

The science and other stuff to know

In the study, which enrolled around 1,800 patients with early-stage Alzheimer’s disease, patients were given twice-weekly infusions of the experimental drug, called Lecanemab. After an 18-month medication trial, Alzheimer’s patients’ cognition who took the actual drug declined by 27 percent less than those on a placebo.

The study also showed that Lecanemab reduced toxic plaques in the brain and slowed patients’ memory decline and ability to perform day-to-day tasks. This change is modest in the clinical outcome, but it’s the first time any drug has been clearly shown to alter the disease’s trajectory.

Lecanemab is an antibody that finds and removes a protein called amyloid that builds up and forms clumps in the brains of people with Alzheimer’s disease. Unlike Aduhelm, which was recently approved for treating the disease, Lecanemab targets forms of amyloid that haven’t yet clumped together, thus striking at the heart of the disease rather than just treating symptoms. However, the drug has a small risk of significant side effects, including brain swelling and bleeding.

So what?

The race to stem the progression of Alzheimer’s comes as the number of Americans living with the disease is projected to rise to nearly 13 million by 2050, according to Alzheimer’s Association. Globally, the figure could reach 139 million by 2050 without effective treatment, as per World Health Organization. Thus, Lecanemab potentially offers hope for patients and their families desperate for an effective treatment. The FDA is expected to approve the drug in January 2023. It’s hoped to achieve full commercialization in the US, Europe, and Japan by the end of 2023.

What’s next?

While Lecanemab successfully altered the progression of Alzheimer’s disease, more research on the drug is needed. “Alzheimer’s is an extremely complex disease, and amyloid-related pathology is unlikely to be the only player,” said Dr. Kristian Steen Frederiksen, director of a clinical trial unit at the University of Copenhagen, and added, “therefore, targeting a single target is not likely to produce large effect sizes.”

There are also questions about whether the drug could slow cognitive and functional decline at an even earlier stage of the disease. So Eisai is recruiting people with a high risk of Alzheimer’s who haven’t yet developed symptoms to take part in further trials to try to help answer the remaining questions.