Eisai Submits New Drug Application for Subcutaneous Formulation of “LEQEMBI®” for the Treatment of Early Alzheimer’s Disease in Japan

Core Viewpoint - The announcement highlights Eisai and Biogen's application for lecanemab's subcutaneous formulation in Japan, which, if approved, would be the first at-home injection treatment for Alzheimer's disease in the country [1][2]. Group 1: Product Development and Approval - Eisai has filed a new drug application for lecanemab seeking approval for a subcutaneous autoinjector (SC-AI) in Japan [1]. - The application is based on Phase 3 Clarity AD open-label extension data, confirming that the once-weekly SC-AI 500mg administration is equivalent to the intravenous (IV) administration every two weeks [2]. - If approved, the SC-AI would allow patients to receive treatment at home, reducing the need for hospital visits for IV administration [3]. Group 2: Clinical Efficacy and Safety - Lecanemab targets both protofibrils and amyloid plaques, addressing the underlying neurotoxic processes in Alzheimer's disease [4]. - The safety profile of subcutaneous administration is similar to IV administration, with less than 2% incidence of systemic injection-related reactions [2]. Group 3: Market Presence and Regulatory Status - Lecanemab is currently approved in 51 countries and regions and is under regulatory review in 9 countries [4][9]. - The drug received manufacturing and marketing approval in Japan in September 2023 for treating mild cognitive impairment and mild dementia due to Alzheimer's disease [9]. Group 4: Collaboration and Strategic Alliances - Eisai leads the global development and regulatory submissions for lecanemab, with Biogen co-commercializing and co-promoting the product [5][11]. - The collaboration between Eisai and BioArctic for the development of lecanemab has been ongoing since 2005, with Eisai obtaining global rights for its commercialization [12].