Eisai shares positive data on subcutaneous Leqembi

Oct. 26, 2023

Eisai and partner Biogen announced new data on subcutaneous administration of early Alzheimer’s Disease drug, Leqembi, finding that the new formulation clears more plaque than the approved intravenous version.

In a preliminary analysis of an open-label extension of the Clarity AD study, the subcutaneous administration showed 14% greater amyloid plaque removal than biweekly IV administration using amyloid PET at 6 months of treatment. 

Additionally, Eisai found that with the weekly subcutaneous administration, blood concentration levels of the drug were 11% higher than the biweekly IV formulation. According to Eisai, this could allow the drugmaker to select a dose that achieves blood concentrations that are comparable to the IV dose.

However, the new formulation still showed Leqembi's familiar side effect — amyloid-related imaging abnormalities (ARIA) — including cerebral microhemorrhage due to ARIA, cerebral hemorrhage and brain surface hemosiderin deposition. 

Leqembi, anti-amyloid beta protofibril antibody, was approved in January under an Accelerated Approval pathway and then the FDA officially changed the approval status to traditional approval in July.

With the new data in hand, Eisai and Biogen plan to apply for U.S. approval of subcutaneous Leqembi by the end of March.