Eisai Completes Submission of Lecanemab for Alzheimer’s Disease

Eisai has completed the rolling submission to FDA for an accelerated approval of lecanemab, another monoclonal antibody that targets beta amyloid, to treat mild cognitive impairment in patients with early Alzheimer’s disease. Eisai has requested priority review.

Eisai is continuing with a confirmatory phase 3 study of lecanemab with almost 1,800 patients enrolled and with results expected in the fall of this year. The FDA has agreed that this trial could be used as the confirmatory study to verify clinical benefit.

The BLA submission for lecanemab is based on clinical, biomarker and safety data from the proof-of-concept phase 2b in 856 people with early Alzheimer’s disease with confirmed presence of amyloid pathology, biomarker and safety data from an open-label extension study, and blinded safety data from the confirmatory phase 3 study.

The phase 2b study,explored the impact of treatment with lecanemab on reducing amyloid plaque and clinical decline. At 18 months of treatment, lecanemab reduced brain amyloid by a mean of 0.306 standardized uptake value ratio (SUVR)—a common quantitative method used to measure comparisons using positron emission tomography (PET). More than 80% of patients became amyloid negative by visual read.

The study also found that the reduction in amyloid was correlated with slower clinical decline on Alzheimer’s Disease Composite Score, Clinical Dementia Rating-Sum-of-Boxes, and Alzheimer Disease Assessment Scale-Cognitive Subscale at the treatment group and patient level.

A simulation model conducted by Eisai and published in April 2022 in the journal Neurology and Therapy found that lecanemab can potentially slow the rate of disease progression, maintaining treated patients for a longer duration in earlier stages of Alzheimer’s disease. In this projection, the mean time advancing to mild, moderate, and severe Alzheimer’s dementia was longer for patients in the lecanemab-treated group than for patients in the standard of care group by two and half years.

The FDA granted breakthrough therapy designation to lecanemab in June 2021 and fast track designation in December 2021. 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.