A monoclonal antibody treatment for Alzheimer’s disease called lecanemab slows the progression of cognitive decline by 27% compared with a placebo, Biogen and Eisai said. Results of the study were published in the journal Alzheimer’s and Dementia.
The findings are a positive surprise, following years of setbacks and failures for similar Alzheimer’s drugs. Aside from providing Biogen and Eisai a much-needed win, lecanemab’s results might also reinvigorate research into the central hypothesis surrounding Alzheimer’s, which focuses on the buildup of a protein called amyloid beta in the brain as the root of the disease.
Dr. Richard Isaacson, director of the Alzheimer’s Prevention Clinic in the Center for Brain Health at Florida Atlantic University’s Schmidt College of Medicine, said, “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.”
“I don’t think one study will prove a very long-standing controversial hypothesis,” says Brent Forester, director of the Geriatric Psychiatry Research Program at McLean Hospital in Belmont, Massachusetts, who helped to run the clinical trial for lecanemab. “But one positive study supports the hypothesis.”
“There is a very detrimental second protein called tau that needs to be addressed,” says Liana Apostolova, a neurologist at the Indiana University School of Medicine in Indianapolis who has consulted for Biogen and Eisai. Tau also deposits in the brains of people who have Alzheimer’s. “And tau is actually the one that really strongly correlates with cognitive decline,” she adds.
A multi-drug approach targeting both amyloid and tau “would be the most successful in terms of a relentless neurodegenerative disease such as Alzheimer’s,” Apostolova says.
We should note that national statistics show that Black Americans are much more likely to have dementia risk factors and later-stage disease progression than Whites. Therefore, clinicians are concerned that this treatment’s costs may not outweigh its minor benefits.