Eisai-Biogen Alzheimer's Drug Data Confirms Benefits, FDA Staff Says

By Leroy Leo and Khushi Mandowara

June 08, 2023

(Reuters) - U.S. Food and Drug Administration staff on Wednesday said data from a late-stage trial of Eisai and Biogen's Alzheimer's disease drug suggests it offered a meaningful benefit to patients and safety concerns likely would not hamper its chances of a traditional approval.

The FDA staff did not highlight any new risks linked to the drug, Leqembi, in documents released ahead of a meeting of a panel of external advisers on Friday that will discuss the companies' application for full approval.

Analysts said the documents seemed to suggest approval for the drug. The FDA decision is expected by July 6.

"Our first impressions suggest we should expect an uncontroversial panel on Friday that will end in a likely favorable vote," RBC Capital Markets analyst Brian Abrahams said, adding that he sees annual sales eventually reaching $10 billion.

Eisai's application for a full approval is based on data showing Leqembi slowed the rate of cognitive decline in patients with early Alzheimer's by 27% compared to a placebo.

Use of certain blood thinners with Leqembi has been linked to a risk of brain hemorrhage. Two Alzheimer's patients on blood thinners taking part in an extension of the late-stage trial died. But the FDA staff said these risks can be described in the prescribing information for the drug.

The staff asked panelists to discuss the risk of serious side effects associated with the use of Leqembi in patients with a hard to diagnose condition called cerebral amyloid angiopathy, in which the protein amyloid that the drug targets builds up in the walls of arteries in the brain.

A third death was reported in a patient treated with Leqembi in the trial extension who had this condition, but the association could not be confirmed. Many Alzheimer's patients have this condition, and presumably some also received the drug without incident, according to the briefing documents.

Shares of Biogen were up 2.2%.

Traditional approval is expected to boost demand for Leqembi with wider insurance coverage under the U.S. government's Medicare plan, which provides health benefits to Americans age 65 and over. Most U.S. Alzheimer's patients are Medicare eligible.

The drug's current accelerated approval, granted in January, has been used by Medicare to justify a policy that restricts coverage of the drug only to those in a clinical trial. No such trials are underway and Leqembi currently has no Medicare coverage, Eisai's U.S. Chief Executive Ivan Cheung said in an interview on Tuesday.

More than 6 million Americans have Alzheimer's, according to the Alzheimer's Association.

(Reporting by Leroy Leo and Khushi Mandowara in Bengaluru; Additional reporting by Julie Steenhuysen in Chicago; Editing by Anil D'Silva and Bill Berkrot)