The US Food and Drug Administration has approved the supplemental biologics licence application (sBLA) of Eisai and Biogen's Leqembi (lecanemab-irmb) for maintenance dosing once every four weeks for the early stages of Alzheimer's disease.
The approval is particularly for individuals with mild cognitive impairment or who are at the mild dementia stage.
Individuals may transition to a 10 mg/kg once every four weeks regimen after an 18-month initiation phase or continue with the bi-weekly regimen.
The approval is supported by data from the Phase II study (Study 201) and its long-term extension (LTE), along with the Clarity Alzheimer's study and its LTE.
Modelling simulations suggest that the new dosing schedule will maintain the therapy's clinical and biomarker benefits.
Operated by continuously clearing protofibrils and rapidly clearing plaque, Leqembi claims to address the progressive nature of Alzheimer's.
The therapy is already approved in Japan, China, the US, South Korea and the UK.
The European Medicines Agency’s Committee for Medicinal Products for Human Use recommended the therapy for approval in November 2024.
Eisai has filed for approval in 17 nations and regions. It leads the development and regulatory submissions for the therapy globally, with both companies jointly promoting and commercialising the product.
The US regulator has set a Prescription Drug User Fee Act (PDUFA) action date of 31 August 2025 for Eisai’s sBLA for the Leqembi subcutaneous autoinjector.
Eisai holds the final decision-making authority.
Lecanemab, developed through a strategic research alliance between Eisai and BioArctic, is a humanised immunoglobulin gamma 1 (IgG1) monoclonal antibody targeting aggregated soluble and insoluble forms of amyloid-beta (Aβ).
