A study released Tuesday showed a closely-watched Alzheimer's drug slowed cognitive decline among people with early signs of the disease but also carries safety risks for some patients.
The peer-reviewed study reported more detailed results on Alzheimer's drug lecanemab, which targets amyloid beta in the brains of patients to slow memory and thinking problems.
But while the study concluded the drug slowed memory and thinking decline, it was "associated with adverse events" such as brain swelling and bleeding.
The late-stage study is the latest test to a three decade-old theory that Alzheimer's disease is triggered by amyloid beta plaques in patients' brains and can be slowed by drugs that target the buildup of those plaques.
Drug companies have struggled through a long list of failed clinical trials with drugs that target amyloid in different ways. Earlier this month, Roche reported a late-stage study of its Alzheimer's drug gantenerumab failed to slow decline enough to be considered statistically significant.
Meanwhile, Biogen's Aduhelm became the first new amyloid-targeting Alzheimer's drug to gain FDA approval last year. It was controversial because it was based on two studies that ended prematurely and yielded mixed results.
'Delaying disease progression'
Maria Carrillo, chief science officer of the Alzheimer’s Association, said the lecanemab study "really confirms that this treatment can provide a meaningful change in the course of a disease for people at the earliest stages of Alzheimer's."
In new data released Tuesday night at the Clinical Trials on Alzheimer's Disease conference in San Francisco and published in the New England Journal of Medicine, researchers reported lecanemab showed moderate benefit while also carrying safety risks for some patients.
Drug manufacturers Eisai and Biogen recruited 1,795 people with earlier Alzheimer's disease and amyloid beta in the brain. Participants received either a 10 mg per kilogram dose every two weeks over 18 months or a placebo. In September, the two companies reported in a press release that the drug reduced cognitive decline by 27% in people who received the drug compared to placebo.
The study concluded people with early signs of the mind-robbing disease who took the drug experienced "moderately less decline on measures of cognition and function" when compared to a placebo group. But the researchers also reported the drug was "associated with adverse events" such as brain swelling and bleeding.
People on the drug reported a slightly higher rate of side effects compared to those on placebo. About 1 in 4 people on the drug had "infusion-related" reactions, and more than 1 in 10 had brain swelling and bleeding revealed during brain scans.
Fewer than 1% of trial participants reported irregular or rapid heartbeats, fainting or chest pain.
Side effects prompted 6.9% of people on the drug to drop out of the study, or more than double the 2.9% from the control group.
Earlier media reports linked lecanemab to two patient deaths, the most recent involving a woman who suffered a stroke and was administered a clot-busting medication at a Chicago hospital, Science reported.
But the study found fewer than 1% of patients died while on the drug or placebo. Researchers concluded "no deaths were considered ... to be related to lecanemab" or from brain swelling and tiny bleeds revealed during brain MRIs.
The companies expect the Food and Drug Administration will decide on its application for accelerated approval by Jan. 6.
Ivan Cheung, chairman and CEO of Eisai's Americas region, said the evidence reviewed by independent experts show the drug is effective with tolerable safety.
"These clinical efficacy results and biomarker results really translate into delaying disease progression as well as improved health-related quality of life," Cheung said.
Ken Alltucker is on Twitter at @kalltucker, or can be emailed at firstname.lastname@example.org.
This article originally appeared on USA TODAY: Lecanemab slows cognitive decline for early Alzheimer's, study finds