US approves Alzheimer’s drug that slows rate of cognitive decline

US regulators have approved an Alzheimer’s drug that slowed the rate of cognitive decline in clinical trials, providing one of the first new treatments for the disease in decades.

But the high cost of the drug — priced at $26,500 per year, Eisai said — combined with tough restrictions on reimbursement by US government-funded health schemes will severely limit the number of patients able to access the medicine, at least for now.

The US Food and Drug Administration on Friday said it had approved lecanemab under an accelerated approval process, describing the medication as “an important advancement in the ongoing fight” to effectively treat Alzheimer’s.

About 50mn people worldwide suffer from Alzheimer’s disease, and until now there has been no effective treatment that can slow the rate at which the illness progresses.

Lecanemab, which was co-developed by Tokyo-based Eisai and US biotech Biogen, is a monoclonal antibody that acts by reducing the build-up of sticky plaques in the brain called beta-amyloid. Phase 3 trial results published in November showed it slowed the rate of cognitive decline in early-stage Alzheimer’s patients by 27 per cent compared to placebo, a moderate but statistically significant result, say experts.

The drug, which is administered via twice-a-month intravenous infusions, follows years of failure of similar amyloid-reducing medications, sparking intense debate between academics over the causes of Alzheimer’s.

The FDA’s approval of the drug was welcomed by Alzheimer’s support groups, which say lecanemab can “meaningfully change the course of the disease for people in the earliest stages of Alzheimer’s”.

But some physicians question whether the reduction in the rate of cognitive decline in patients is “clinically meaningful” and have raised concerns over the safety profile of lecanemab, which can cause swelling and bleeding in the brain.

At least three Alzheimer’s patients have died from brain bleeds after taking lecanemab, including two people who were also taking blood-thinning medicines.

Eisai has said it does not believe lecanemab was responsible for the deaths but cannot rule out the possibility that it contributed to the bleeds. A warning will be attached to the label of the drug, which will carry the brand name Leqembi, about potential side effects, the company said.

Ivan Cheung, chief executive of Eisai’s US operations, said Leqembi would launch in January but sales would be limited in the short-term because the drug is not covered by Medicare, the US national health insurance scheme for people aged 65 years or older.

Last year US health authorities restricted government funding for all amyloid-reducing monoclonal antibody drugs approved under the FDA’s accelerated approval process to patients taking part in clinical trials.

This followed controversy caused by the agency’s decision to approve aducanemab — another amyloid-reducing Alzheimer’s drug co-developed by Biogen and Eisai — despite concerns expressed by experts over the handling of the clinical trial, the drug’s efficacy and its safety profile.

The FDA’s accelerated approval process allows the agency to give a green light to drugs that treat serious conditions in advance of conclusive clinical trial data.

Cheung said Eisai would apply for full approval for Leqembi imminently and talk to the US Centers for Medicare & Medicaid Services about relaxing reimbursement restrictions for the treatment.

“Our primary goal [in this first phase] is to get health systems ready so that when CMS lifts the restrictions post conditional approval we can be in better shape to launch a campaign across the country,” Cheung said. “It is not beyond the realm of possibility that this can happen by the end of the calendar year and that’s what we hope.”

Analysts forecast lecanemab could generate peak sales worth $13bn a year depending on the level of access granted by Medicare and other countries’ insurance schemes.

But some experts are sceptical about the drug’s prospects because of concerns about its clinical effectiveness, safety profile and reimbursement by insurers.

Robert Howard, professor of old age psychiatry at University College London, said there are huge barriers to the take-up of lecanemab because of the difficulty in administering the treatment within health systems.

“Most of my colleagues will sit this one out and — based on what we know about the risks and benefits — I think they’d be wise to do so,” he said.