FDA grants Eisai Alzheimer's drug full approval

July 7, 2023

This week, the FDA officially changed the approval status of Eisai's Alzheimer's treatment, Leqembi, from accelerated approval to traditional approval.

Leqembi, which Eisai is co-commercializing and co-promoting with Biogen, initially received approval in January through the Accelerated Approval pathway, but not without controversy. In November 2022, two clinical trial deaths were associated with the drug's use alongside blood thinners. A neuropathologist involved in one patient's autopsy expressed the belief that the illness and death were caused by the treatment, stating that the patient would be alive if not for the treatment.

Despite these concerns, the drug received clearance for accelerated approval. This pathway allows the FDA to approve drugs for serious conditions when there is an unmet medical need and the drug demonstrates an effect on a surrogate endpoint that reasonably predicts therapeutic benefits for patients. 

In this case, the endpoint was the reduction of amyloid plaques, which was reasonably expected to lead to clinical benefits for patients. As a postmarketing requirement, the FDA mandated a confirmatory clinical trial, known as Study 301 (CLARITY AD), a phase 3 randomized, controlled clinical trial that evaluated the efficacy of Leqembi. 

A few weeks ago, the FDA’s Peripheral and Central Nervous System Drugs Advisory Committee voted unanimously to back the treatment's full approval. Ahead of the meeting, the FDA shared a briefing document outlining its support for Leqembi, stating that the risks identified in confirmatory trials could be detailed in the prescribing information and should not be expected to prevent the traditional approval of the drug.

About the approval expansion, Teresa Buracchio, acting director of the Office of Neuroscience at CDER, said in a statement this week that, “Today’s action is the first verification that a drug targeting the underlying disease process of Alzheimer’s disease has shown clinical benefit in this devastating disease."

Eisai had been actively working on securing payer coverage for Leqembi. Recently, CMS administrator Chiquita Brooks-LaSure announced that if the drug received traditional approval from the FDA, Medicare will provide coverage for the drug in appropriate health care settings. With the recent approval expansion, Leqembi will now be covered by Medicare for AD patients, with the same restrictions Biogen's Aduhelm. 

Eisai estimates the per-patient-per-year value of Leqembi to the U.S. society to be $37,600, but says it will price the drug at $26,500 per year.