In Jul. 10, 2024, Eisai and Biogen announced that the Department of Health in Hong Kong has approved humanized anti-soluble aggregated amyloid-beta (Aβ) monoclonal antibody “LEQEMBI^®” (brand name in Hong Kong: “樂意保^®”, generic name: lecanemab) for treatment of Alzheimer’s disease (AD).

Treatment with LEQEMBI should be initiated in patients with mild cognitive impairment (MCI) or mild dementia stage of disease (collectively referred to as early AD), the population in which treatment was initiated in clinical trials. LEQEMBI selectively binds to soluble Aβ aggregates (protofibrils*), as well as insoluble Aβ aggregates (fibrils) which are a major component of Aβ plaques, thereby reducing both Aβ protofibrils and Aβ plaques in the brain.