Eisai Co., Ltd. and Biogen Inc. announced that the European Medicines Agency (EMA) has accepted a marketing authorization application (MAA) for lecanemab (Brand Name in the U.S.: LEQEMBI™), an investigational anti-amyloid beta (Aß) protofibril antibody, for the treatment of early Alzheimer's disease (mild cognitive impairment due to Alzheimer's disease (AD) and mild AD dementia) with confirmed amyloid pathology, for review following a standard timeline. In the U.S., lecanemab was granted accelerated approval as a treatment for AD by the U.S. Food and Drug Administration (FDA) on January 6, 2023. On the same day, Eisai submitted a Supplemental Biologics License Application (sBLA) to the FDA for approval under the traditional pathway based on the results from the Phase III Clarity AD confirmatory study.

In Japan, Eisai submitted a marketing authorization application to the Pharmaceuticals and Medical Devices Agency (PMDA) on January 16, 2023. In China, Eisai has initiated submission of data for a BLA to the National Medical Products Administration (NMPA) of China in December 2022. Eisai serves as the lead of lecanemab development and regulatory submissions globally with both Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

Lecanemab (Brand Name in the U.S.: LEQEMBI™) is the result of a strategic research alliance between Eisai and BioArctic. Lecanemab is a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aß). Lecanemab selectively binds and eliminates Aß protofibrils that are thought to contribute to the neurotoxicity in AD.

As such, lecanemab may have the potential to have an effect on disease pathology and to slow down the progression of the disease. In the U.S., LEQEMBI was granted accelerated approval by the U.S. Food and Drug Administration (FDA) on January 6, 2023. LEQEMBI is indicated for the treatment of Alzheimer's disease (AD) in the U.S. Treatment with LEQEMBI should be initiated in patients with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was initiated in clinical trials.

There are no safety or effectiveness data on initiating treatment at earlier or later stages of the disease than were studied. This indication is approved under accelerated approval based on reduction in Aß plaques observed in patients treated with LEQEMBI. Continued approval for this indication may be contingent upon verification of clinical benefit in a confirmatory trial.

The Clarity AD study of lecanemab met its primary endpoint and all key secondary endpoints with highly statistically significant results. Eisai has completed a lecanemab subcutaneous bioavailability study, and subcutaneous dosing is currently being evaluated in the Clarity AD (Study 301) OLE.