Biogen & Partner Eisai Get EU Nod for Alzheimer's Drug Leqembi

Core Viewpoint - The European Commission has granted marketing authorization for Leqembi (lecanemab) to treat early Alzheimer's disease, marking a significant regulatory milestone for Biogen and Eisai [1][4][7]. Company Developments - Biogen's partner, Eisai, is responsible for the clinical development and regulatory submissions for Leqembi, although both companies co-commercialize the drug [2]. - Biogen's stock has decreased by 23.5% year-to-date, contrasting with a 6.5% decline in the industry [3]. Regulatory Approval Process - The approval for Leqembi followed a series of delays, including a negative opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) in July 2024 [4][5]. - The CHMP initially raised concerns about the drug's safety, particularly regarding amyloid-related imaging abnormalities (ARIA) [6]. - After reassessing new safety data, the CHMP reaffirmed its positive opinion for Leqembi in February 2025 [9]. Market Performance - Leqembi has been approved in multiple countries, including the United States, China, Japan, and Great Britain [10]. - Sales of Leqembi showed a sequential improvement, with Eisai reporting nearly $87 million in global revenues in Q4 2024, reflecting a 30% increase [11]. Future Prospects - A less frequent maintenance intravenous dosing version of Leqembi was approved by the FDA in January 2025, with a subcutaneous autoinjector under review [12]. - Both companies believe Leqembi has the potential to achieve blockbuster sales due to the significant unmet medical need for Alzheimer's treatments [12]. Competitive Landscape - Leqembi and Eli Lilly's Kisunla are currently the only two FDA-approved drugs for early symptomatic Alzheimer's disease [13]. - Both drugs target the reduction of amyloid beta (Aβ) plaque in the brain, which is associated with cognitive decline in Alzheimer's patients [14].