US regulators approved a breakthrough Alzheimer’s drug that reduced cognitive decline in a major study.
The US Food and Drug Administration has accelerated approval of Leqembi, also known as lecanemab, one of the first experimental drugs to convincingly slow memory and thinking impairment in patients.
The decision has led to calls for the UK to work with its manufacturers to test the drug “as a matter of urgency”.
Following FDA approval, doctors in the US can prescribe the drug to Alzheimer’s patients, specifically those with mild or early-stage disease.
Leqembi, jointly developed by Japan’s Eisai and America’s Biogen, is a rare success in a field accustomed to failed experimental treatments for the incurable disease.
The drug represents “an important advance in the ongoing fight to effectively treat Alzheimer’s disease,” the FDA said in announcing its decision.
The drug comes at a high price: Eisai said Leqembi would have a starting price of $26,500 per year.
The delay in cognitive decline caused by the drug probably amounts to only several months, but some neurologists say it could still significantly improve people’s lives.
“This drug is not a cure. It doesn’t prevent people from getting worse, but it does slow the progression of the disease considerably,” said Dr. Joy Snider, a neurologist at Washington University in St. Louis.
“That could mean someone could have an extra six months to a year to be able to drive.”
The FDA approval comes after the US regulator came under heavy criticism regarding its 2021 approval of another Alzheimer’s drug, Aduhelm.
There was a lot of controversy over whether Aduhelm worked, with a US congressional investigation saying the approval process was “rife with irregularities.” It led to three high-level resignations at the FDA.
Lecanemab has received a warmer reception, but some experts have raised questions about the drug’s safety and whether it provides significant benefit.
Preliminary data from a trial by Leqembi was published in September and found that it slowed cognitive decline in Alzheimer’s patients by 27%.
The phase three trial involved nearly 1,800 people, divided between those who received the drug and those who received a placebo, and lasted 18 months.
The full data from the trial, published in the New England Journal of Medicine, built on the findings, but also raised concerns about the incidence of “adverse effects” such as brain bleeding and swelling.
Results showed that 17.3% of patients given the drug experienced brain bleeds, compared with 9% of those given a placebo.
And 12.6% of those taking the drug experienced brain swelling, compared to just 1.7% of those in the placebo group.
Deaths were reported at approximately the same rate in both arms of the drug trial.
In Alzheimer’s disease, two key proteins, tau and amyloid beta, accumulate in tangles and plaques, together known as aggregates, which cause brain cell death and lead to brain shrinkage.
Leqembi works by targeting the amyloid.
Despite safety concerns, the move to approve its use in the United States was hailed by Alzheimer’s Research UK as a “major milestone”.
Hilary Evans, chief executive of Alzheimer’s Research UK, said: “We know that today’s news can cause mixed emotions. There is still a long way to go before lecanemab can reach patients in the UK. This period of uncertainty, while We expect the UK regulator to carry out its own review, it may be difficult for people with Alzheimer’s and their loved ones.”
It added: “Alzheimer’s Research UK has written to the manufacturer of lecanemab, Eisai, asking them to work with the UK government, UK medicines regulators and the NHS to ensure an evidence-based decision can be made on the safety and efficacy of lecanemab as a matter of urgency.”