FDA Approves New Drug for Early Alzheimer’s

Alzheimer Mike July 23, 2024

Editor’s Note: This story was updated with the FDA’s approval of donanemab.

In a highly anticipated decision, the U.S. Food and Drug Administration (FDA) has approved the early-stage Alzheimer’s drug Kisunla (donanemab).

This makes it the second medicine, after Leqembi (lecanemab), that can slow the progression of early-stage Alzheimer’s disease by targeting the underlying processes in the brain that lead to cognitive decline.

An FDA advisory panel endorsed approval of the Eli Lilly drug last month.

“The trial data demonstrated, convincingly, that Kisunla reduces the rate of cognitive and functional decline in patients in the mild cognitive impairment and mild dementia stages of Alzheimer’s disease,” said Teresa Buracchio, MD, director of the office of neuroscience in the FDA’s center for drug evaluation and research, in a statement. “Today’s approval is evidence of the FDA’s commitment to helping more safe and effective drugs to treat Alzheimer’s disease become available.”

Amyloid Antibodies Clear Brain Plaques Connected to Alzheimer’s

Like lecanemab, donanemab is in a family of medicines known as amyloid antibodies, which are designed to clear the brain of plaque deposits that may hasten cognitive decline caused by Alzheimer’s disease. Another amyloid antibody, Aduhelm (aducanumab), won conditional FDA approval in 2021 despite an FDA advisory committee recommendation against it; they were concerned about the lack of clear benefits. Aduhelm didn’t win full FDA approval, and is being discontinued this year.

In a late-stage clinical trial of 1,182 people with early symptomatic Alzheimer’s disease, donanemab slowed cognitive decline by 35 percent compared with a placebo and resulted in 40 percent less decline in activities of daily living like driving, managing finances, and participating in hobbies, according to results published in JAMA.

One safety concern with donanemab is the potential for people who take this drug and other amyloid antibodies to experience what’s known as ARIA, or amyloid-related imaging abnormalities. ARIA shows up on brain scans and can sometimes involve seizures or potentially life-threatening brain swelling or bleeding, although many people don’t experience symptoms.

Brain Bleeding and Swelling

In the late-stage donanemab trial, 37 percent of people on the drug experienced some type of ARIA with bleeding or swelling in the brain.

ARIA was also seen in a late-stage trial of lecanemab published in The New England Journal of Medicine. This trial found that people taking the drug experienced 27 percent slower cognitive decline than people on placebo. It also found that 17 percent of people on lecanemab experienced ARIA with brain bleeding, and 12 percent had ARIA with brain swelling.

Like lecanemab, donanemab will require that patients get regular magnetic resonance imaging (MRI) scans to look for and address any bleeding or swelling in the brain.

“Most people aren’t going to get side effects that are symptomatic with ARIA,” says Lawrence Honig, MD, PhD, a neurologist at NewYork-Presbyterian/Columbia University Irving Medical Center in New York City. “The likelihood of symptomatic side effects that you feel and you notice or your family notices is less than 10 percent even for those most at risk.”

While the risk is slightly higher with donanemab than with lecanemab, some people may still prefer donanemab because it’s administered via monthly infusions instead of every two weeks with lecanemab, Dr. Honig says. However, at least initially, it may be easier for some people to access lecanemab because the drug has been on the market longer and supplies may be more readily available, Honig notes.

The drug will cost $695 per vial, according to a company press release. That would total $32,000 for a 12-month treatment. A patient’s actual cost will depend on their insurance and the length of treatment.