A monoclonal antibody treatment for Alzheimer’s disease called lecanemab slowed the progression of cognitive decline by 27 percent compared with a placebo in a new clinical trial. The phase 3 global clinical trial of the drug found that it improved people’s abilities to perform everyday tasks, aided cognition and decreased amyloid levels — a protein that’s a hallmark of Alzheimer’s.
Dr. Richard Isaacson, director of the Alzheimer’s Prevention Clinic in the Center for Brain Health at Florida Atlantic Univ., said the trial isn’t proof of the amyloid hypothesis. “It proves that, in people with a certain amount of amyloid in their brain at a certain stage of the disease, that this drug works. In terms of proving a mechanism by using a drug, no. Alzheimer’s is a very heterogeneous disease.”
But, he adds, that doesn’t diminish the potential importance of the trial. “In the past, reducing amyloid in the brain has not always been tied to cognitive improvements or any meaningful clinical improvements. In this study, every endpoint was positive. That’s never happened before.”
“For people in the earliest stages of Alzheimer’s, this treatment has the potential to change the course of the disease in a clinically meaningful way,” said the Alzheimer’s Association. “These results indicate lecanamab may give people more time at or near their full abilities to participate in daily life, remain independent and make future health care decisions. Treatments that deliver these benefits to those with mild cognitive impairment (MCI) due to Alzheimer’s disease and early Alzheimer’s dementia are just as valuable as treatments that extend the lives of those with other terminal diseases.”
Last year, the FDA approved a new Alzheimer’s drug for the first time in 20 years. The drug, Aduhelm, clears plaque from the brain but hasn’t been shown to fight cognitive decline. The FDA’s own panel of outside experts recommended against approval. But it went through.
On the other hand, lecanemab removes amyloids from the body and improves cognition. Questions as to whether the amyloids are the problem or if there are other factors at work remain. But, while the exact mechanism of the drug may not be understood, it’s clear that lecanemab offers results. The FDA is reviewing the data on lecanemab and will be making their approval decision on Jan. 6.