MRI image of the brain showing the area of the Alzheimer patient.
The Food and Drug Administration on Friday granted accelerated approval for the Alzheimer’s drug lecanemab, the second treatment for Alzheimer’s disease biogen and his Japanese partner Eisai get the green light early within two years.
The FDA’s approval comes after clinical trial results published in November indicated that lecanemab slightly slows cognitive decline in people with mild impairment due to Alzheimer’s disease, but the treatment also carries risks of brain swelling and bleeding.
Eisai, who led the development of lecanemab, prices the treatment at $26,500 a year in the US. It will be sold under the name Leqembi.
The FDA can accelerate the approval of a drug to get it to market quickly if it is expected to help patients with serious conditions more than is currently available. Biogen and Eisai filed for accelerated approval in July.
“Alzheimer’s disease greatly disables the lives of those who suffer from it and has devastating effects on their loved ones,” said Dr. Billy Dunn, director of the FDA’s division of neuroscience, said in a statement. “This treatment option is the latest therapy to target and influence the underlying disease process of Alzheimer’s, rather than just treating the symptoms of the disease.”
More than 6.5 million people in the US suffer from Alzheimer’s disease. The irreversible disease destroys memory, thinking ability and ultimately the ability to perform simple tasks.
The decision on lecanameb comes after Congress released a damning report last week on how the FDA handled the controversial approval of another Alzheimer’s drug developed by Biogen and Eisai, called Aduhelm. The 2021 approval of that treatment, which experts say showed no clear clinical benefit, was “riddled with irregularities,” according to the report.
The congressional report said the “FDA must take prompt action to ensure that its processes for reviewing future Alzheimer’s treatments do not raise the same doubts about the integrity of the FDA’s review.”
Moderately slows down the disease
Lecanemab is a monoclonal antibody that targets a protein called amyloid that accumulates in the brains of people with Alzheimer’s disease. The antibody is administered intravenously every two weeks in doses determined by a patient’s body weight at 10 milligrams per kilogram.
The FDA approved lecanemab based on the reduction in amyloid plaque seen in clinical trial participants who received the treatment, according to a statement from the agency. Participants who did not receive the treatment, the placebo arm, had no reduction in amyloid plaque.
The results of the clinical trial, published in the New England Journal of Medicine, found that cognitive decline was 27% slower over 18 months in people who received lecanemab compared to those who did not receive the treatment. The study was funded by Biogen and Eisai.
Cognitive decline was measured using a system called the clinical dementia classification, an 18-point scale with a higher score indicating a greater degree of impairment. It measures cognitive functions such as memory, judgment and problem solving.
Alzheimer’s disease progressed an average of 1.21 points in the group receiving lecanemab compared to 1.66 points in the group not receiving the treatment, a modest difference of 0.45 points.
Nearly 1,800 people aged 50 to 90 with early Alzheimer’s participated in the study, about half of whom received lecanemab and half of whom did not.
While lecanemab may slightly slow cognitive decline, the treatment also carries risks.
Nearly 13% of those who received lecanemab developed brain swelling compared to about 2% in the group who did not receive the treatment. However, most of these cases were mild to moderate in severity, did not cause symptoms and generally resolved within four months.
About 3% of patients receiving lecanemab had more severe brain swelling with symptoms such as headache, visual disturbances and confusion.
About 17% of those who received lecanemab had cerebral hemorrhage, compared to 9% in the group who did not receive the treatment. The most common symptoms associated with the bleeding were dizziness.
Overall, 14% of people who received lecanemab experienced serious side effects in the clinical trial, compared to 11% of those who did not receive the treatment.
The study authors said longer clinical trials were needed to determine the efficacy and safety of lecanemab in patients with early-stage Alzheimer’s disease.
The FDA said the prescribing information for lecanemab will include a warning about a risk of swelling and bleeding, commonly referred to as amyloid-related imaging abnormalities.
The death of a clinical trial participant in the Chicago area may also be linked to lecanemab, according to a research letter published this week in the New England Journal of Medicine.
The 65-year-old suffered a stroke and was hospitalized four days after their third lecanemab infusion. A CT scan performed after the patient’s stroke found extensive bleeding in the brain. An MRI performed 81 days before the stroke had found no bleeding.
The patient had also been given a drug called t-PA, which is used to break up blood clots that cause strokes. But extensive brain hemorrhaging would be an uncommon complication of this drug alone, according to the doctors who wrote the study letter.
Investigators involved in the lecanemab clinical trial argued in a letter of reply that the blood clot medication appeared to be the direct cause of the patient’s death, with the first symptoms appearing 8 minutes after they received an infusion of the blood clot buster.