The Japanese approval was based on Phase 3 results from Eisai’s large, global Clarity AD clinical trial in which the antibody therapy met its primary endpoint and all key secondary endpoints
Japan health regulator approves Leqembi for Alzheimer’s disease. (Credit: Sam Moghadam Khamseh on Unsplash)
Eisai and Biogen have received approval for their Leqembi Intravenous Infusion (200 mg, 500mg, lecanemab) in Japan to treat slowing progression of mild cognitive impairment (MCI) and mild dementia caused by Alzheimer’s disease (AD).
Leqembi is a humanised immunoglobulin gamma 1 (IgG1) monoclonal antibody therapy that targets aggregated soluble (protofibril) and insoluble forms of Aβ.
In Japan, the marketing approval application was submitted and received priority review status in January this year. Japan is the second nation to provide its authorisation following the traditional US approval in July 2023.
Eisai CEO Haruo Naito said: “Today Leqembi received approval, making it the first approved anti-amyloid Alzheimer’s disease treatment shown to reduce the rate of disease progression and to slow cognitive impairment in the early and mild dementia stages of the disease in Japan.
“We believe that we have turned a new page in the history of Alzheimer’s disease treatment.”
The Japanese approval was based on Phase 3 results from Eisai’s large, global Clarity AD clinical trial.
In the trial, the antibody therapy met its primary endpoint and all key secondary endpoints, showing statistically significant results and confirming the clinical benefit of Leqembi.
The drug reduced clinical decline on Clinical Dementia Rating Sum of Boxes (CDR-SB), which was also the primary endpoint, by 27% at 18 months compared to placebo.
The secondary endpoint, AD Cooperative Study-Activities of Daily Living Scale for Mild Cognitive Impairment (ADCS MCI-ADL), observed a statistically significant benefit of 37% against placebo.
Biogen president and CEO Christopher Viehbacher said: “With this approval, alongside Eisai, we will be able to help address the devastating impact Alzheimer’s has on people living with the condition as well the emotional, social and financial burden it places on care partners.
“With this approval, alongside Eisai, we will be able to help address the devastating impact Alzheimer’s has on people living with the condition as well the emotional, social and financial burden it places on care partner.”
Eisai said it will conduct a post-marketing special use results survey on all patients who were administered Leqembi until it gathers enough data from a certain number of patients.
Eisai leads Leqembi development and regulatory filings globally. Both firms co-commercialise and co-promote the product with Eisai having final decision-making authority.