Eisai and Biogen's LEQEMBI® (lecanemab) IV maintenance dosing for early Alzheimer’s disease approved in China

On September 29, 2025, Eisai Co., Ltd. ("Eisai") and Biogen Inc. ("Biogen") announced today that humanized anti- soluble aggregated amyloid-beta (Aβ) monoclonal antibody LEQEMBI® (brand name in China: 乐意保®, generic name: lecanemab) has been approved for once every four weeks intravenous (IV) maintenance dosing by the National Medical Products Administration (NMPA) in China. 

In January 2024, LEQEMBI was approved for the treatment of Alzheimer's disease (AD) in patients with mild cognitive impairment (MCI) or mild dementia stage of disease (collectively referred to as early AD) in China. After 18 months of a dosing regimen of 10 mg/kg once every two weeks during initiation phase, a transition to the maintenance dosing regimen of 10 mg/kg once every four weeks may be considered or the regimen of 10 mg/kg once every two weeks may be continued.

AD is a progressive, relentless disease characterized by formation of protein deposits known as plaques made of amyloid-beta aggregates and neurofibrillary tangles made of tau protein in the brains of people living with AD.  It is caused by a continuous underlying neurotoxic process that begins before amyloid plaque accumulation and continues after plaque removal. The data show that Aβ protofibrils and tau tangles play roles in the neurodegeneration process, and LEQEMBI is the only approved therapy that fights AD in two ways – targeting both amyloid plaque and protofibrils, which can impact tau downstream.

Eisai estimates that, as of 2024, there were 17 million patients with MCI or mild dementia due to AD in China in 2024, which is expected to increase with the aging of the population.

Eisai serves as the lead for lecanemab's development and regulatory submissions globally with Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority. In China, Eisai distributes the product and conducts information provision activities through specialized Medical Representatives.

Source: Eisai