3d illustration of the human brain with visible blood vessels illustrating Alzheimer's disease and dementia.
Credit: Lars Neumann/Getty Images

Eisai/Biogen’s Leqembi is approved under accelerated approval by FDA for Alzheimer’s disease. This is the partners’ second try at the disease-modifying market for early-stage Alzheimer’s. Their first attempt was Aduhlem (aducanumab), which was brought to market in 2021 and faced a great deal of controversy about its relative efficacy and price.

“Patients at an early stage of the disease and their caregivers can now consider a new treatment option with their doctors. Our focus now is on the path forward, working alongside Eisai with the goal of making Leqemi available to patients who may benefit from this treatment as soon as possible,” said Christopher A. Viehbacher, President and Chief Executive Officer of Biogen.

The Alzheimer’s therapeutics market was valued at over $4 billion in 2021, and it expected to grow considerably. Eisai said Leqembi’s list price would be $26,500 per year. It could become one of the most profitable drugs in the world.

Leqembi is a humanized immunoglobulin gamma 1 monoclonal antibody that targets aggregated soluble (“protofibril”) and insoluble forms of amyloid beta (Aβ). Protofils are large Aβ aggregated soluble species of 75-500 Kd.

The approval is based on Phase II data that demonstrated that the drug reduced the accumulation of Aβ plaque in the brain, a defining feature of AD. Using the recently published data from the large global confirmatory Phase III clinical trial, Clarity AD, Eisai will file a Supplemental Biologics License Application to the FDA for approval under the traditional pathway.

The company says treatment with Leqembi should be directed to patients with mild cognitive impairment or mild dementia stage of disease, the population studied in clinical trials. This indication is under accelerated approval based on reduction in amyloid beta plaques. Continued approval for this indication may be contingent upon verification of clinical benefit in a confirmatory trial.

The safety of Leqembi has been evaluated in 763 patients who received at least one dose of the drug in Study 201. The most common adverse reactions reported in at least five percent of patients treated with Leqembi were infusion-related reactions, headache, cough, and diarrhea. The most common adverse reaction leading to discontinuation of Leqembi was infusion-related reactions that led to discontinuation in two percent of patients treated with the drug.

“Upon receiving this Accelerated Approval, we will focus on providing important information on proper usage of Leqembi to healthcare professionals. Eisai will also engage with various payers to provide access to Leqembi, offer a patient support program, and will do its utmost to complete submission for traditional approval as soon as possible to serve more people living with early Alzheimer’s disease,” said Haruo Naito, Eisai’s Chief Executive Officer.

The company says Leqembi will be available during or before the week of January 23, 2023, and it announced the U.S. pricing and rationale for the drug this week.

Eisai is the lead of Leqembi development and regulatory submissions globally with both Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

Also of Interest