Eisai, Biogen submit sBLA for Leqembi IV maintenance dose, delay subcutaneous filing

Eisai and Biogen announced their submission of an sBLA to the FDA for the monthly intravenous (IV) maintenance dosing of Leqembi for the treatment of early-stage Alzheimer’s disease, but delay their BLA for a weekly subcutaneous (SC) version.

The sBLA is supported by data from the phase 2 study and its open-label extension, as well as the Clarity AD study and its open-label extension, indicating the treatment's potential in slowing disease progression. The monthly IV dosing will follow an initial biweekly IV phase, aimed at maintaining drug levels to support the clearance of protofibrils, which are associated with neuronal damage in Alzheimer’s disease.

Eisai also planned to submit a rolling BLA for a weekly subcutaneous maintenance dose in March 2024 but was informed by the FDA that additional immunogenicity data and a Fast Track designation for the SC formulation are required. Eisai has requested this Fast Track designation and will proceed with a rolling submission if granted, with a decision expected within 60 days.

Leqembi, an anti-amyloid beta protofibril antibody, won full approval in the U.S. last year, and has also been authorized by regulatory agencies in Japan, and China, with submissions for approval in the European Union, Australia, Brazil, Canada, and other regions. Eisai leads the development and regulatory submissions globally, with co-commercialization and promotion shared with Biogen.