The drug is indicated for adults with mild cognitive impairment or mild dementia, who are non-carriers or heterozygotes of apolipoprotein E ε4 (ApoE ε4) with confirmed amyloid pathology.
TGA’s approval follows a review initiated by Eisai after the regulator’s initial decision in February 2025 not to approve the treatment.
A subsequent review by the Administrative Review Tribunal led to discussions that resulted in the TGA’s approval of Leqembi.
Leqembi, a humanised immunoglobulin gamma 1 (IgG1) monoclonal antibody, targets both soluble and insoluble forms of amyloid-beta (Aβ).
It is a result of collaboration between BioArctic and Japanese drug maker Eisai.
BioArctic developed the antibody based on Professor Lars Lannfelt’s discovery of the Arctic mutation in Alzheimer’s.
Eisai oversees the clinical development, market approval applications, and marketing of Leqembi worldwide. BioArctic holds commercialisation rights in the Nordic region.
Lecanemab has been approved in over 50 countries, including the US, Japan, China, and the European Union (EU), for treating Alzheimer’s disease in patients at the mild cognitive impairment or mild dementia stage.
BioArctic and Eisai have collaborated since 2005, focusing on Alzheimer’s treatment development and commercialisation.
Key agreements include the 2007 development and commercialisation agreement for lecanemab and a 2015 backup agreement for Leqembi.
Additionally, Eisai and Biogen entered a joint development and commercialisation agreement for lecanemab in 2014.
BioArctic incurs no development costs for lecanemab and receives sales milestone payments and royalties on global sales.