Promising Alzheimer’s drug has dangers
AN EXPERIMENTAL Alzheimer’s drug from Eisai and Biogen slowed cognitive decline in a closely watched trial but may carry a risk of serious side effects for certain patients, according to detailed data presented this week.
The drug, lecanemab, was associated with a dangerous type of brain swelling in nearly 13% of patients in the trial that spanned 18 months and enrolled nearly 1 800 participants with early-stage Alzheimer’s.
Some patients also experienced bleeding in the brain, with five suffering macrohaemorrhages and 14% suffering microhaemorrhages – a symptom linked to two deaths of people receiving the drug in a follow-on study.
The companies said in September that lecanemab – an antibody designed to remove sticky deposits of a protein called amyloid beta – reduced the rate of cognitive decline on a clinical dementia scale (CDR-SB) by 27% compared to a placebo.
“All of amyloid-lowering drugs carry a risk for increased brain haemorrhage,” said Dr. Ronald Petersen of the Mayo Clinic in Rochester, Minnesota. “I think the primary outcomes, the secondary outcomes, the amyloid-lowering is pretty impressive.”
The Alzheimer’s Association said the data confirmed that the drug “can meaningfully change the course of the disease,” and called on US regulators to approve the company’s application for accelerated approval.
The full data showed some patients with a genetic risk of developing the disease did not benefit from lecanemab based on the CDR-SB measure. They did show improvement for the trial’s secondary goals, including other measures of cognition and daily function. Overall, lecanemab patients benefited by 23% to 37% compared with a placebo on these secondary trial goals.
“I believe it’s an important benefit that will justify full approval. But of course, we want a bigger benefit,” said Dr Paul Aisen, director of the University of Southern California Alzheimer’s Therapeutic Research Institute and a co-author of the study published in the New England Journal of Medicine.
He said lecanemab was likely to provide greater benefit if given earlier in the disease, “before you’ve accumulated enough irreversible damage to be causing symptoms.”
Detailed data from the study were presented at the Clinical Trials on Alzheimer’s Disease meeting in San Francisco.
Eisai believes the trial results prove a theory that removing amyloid beta from the brains of people with early Alzheimer’s can delay advance of the disease.