TOKYO and CAMBRIDGE, Mass., Sept. 3, 2025 - (JCN Newswire) - Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) and Biogen Inc. (Nasdaq: BIIB, Corporate headquarters: Cambridge, Massachusetts, CEO: Christopher A. Viehbacher, “Biogen”) announced today that Eisai has initiated the rolling submission of the Supplemental Biologics License Application (sBLA) to the U.S. Food and Drug Administration (FDA) for lecanemab-irmb (U.S. brand name: LEQEMBI®) subcutaneous autoinjector(SC-AI), LEQEMBI IQLIK, as a weekly starting dose after the FDA granted Fast Track Status. LEQEMBI is indicated 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).
The sBLA is based on evaluation of subcutaneous (SC) lecanemab administration across a range of doses and as part of sub-studies within the Phase 3 Clarity AD open-label extension (OLE), following the 18-month core study in individuals with early AD. Should the FDA approve the LEQEMBI IQLIK 500mg SC dosing regimen (two 250 mg injections), the autoinjector could be used to administer a once weekly starting dose, as an alternative to bi-weekly (every two weeks) intravenous (IV) dosing. This would expand the option for patients and care partners to receive LEQEMBI treatment from initiation to maintenance at home, offering a choice between IV and SC administration. The current injection time for each LEQEMBI IQLIK autoinjector takes approximately 15 seconds. The SC formulation also has the potential to reduce healthcare resources associated with IV maintenance dosing, such as preparation for infusion and nurse monitoring, while streamlining the overall AD treatment pathway
AD is a progressive, relentless disease with amyloid beta (Aβ) and tau as hallmarks that is caused by a continuous underlying neurotoxic process that begins before amyloid plaque removal and continues afterward.1,2,3 Only LEQEMBI fights AD in two ways – targeting both amyloid plaque and protofibrils*, which can impact tau downstream.
LEQEMBI is currently approved in 48 countries and is under regulatory review in 10 countries.
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.
*Protofibrils are believed to contribute to the brain injury that occurs with AD and are considered to be the most toxic form of Aβ, having a primary role in the cognitive decline associated with this progressive, debilitating condition.1 Protofibrils cause injury to neurons in the brain, which in turn, can negatively impact cognitive function via multiple mechanisms, not only increasing the development of insoluble Aβ plaques but also increasing direct damage to brain cell membranes and the connections that transmit signals between nerve cells or nerve cells and other cells. It is believed the reduction of protofibrils may prevent the progression of AD by reducing damage to neurons in the brain and cognitive dysfunction.2
INDICATION
LEQEMBI® is indicated for the 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, the population in which treatment was initiated in clinical trials.
For more details, please visit: https://www.eisai.com/news/2025/pdf/enews202560pdf.pdf