Eisai And Biogen Announce TGA Approval Of LEQEMBI® For Early Alzheimer’s In Australia

Eisai Co., Ltd. and Biogen Inc. announced that Australia’s Therapeutic Goods Administration (TGA) has approved LEQEMBI® (lecanemab), a humanized anti-amyloid beta monoclonal antibody, for the treatment of adults with early Alzheimer’s disease (mild cognitive impairment or mild dementia due to AD). The approval applies to patients who are either ApoEε4 non-carriers or heterozygous carriers, populations less likely to experience amyloid-related imaging abnormalities (ARIA).

The decision marks a reversal of the TGA’s initial rejection in February 2025, following Eisai’s request for review by the Administrative Review Tribunal. After discussions, Eisai and the TGA reached an agreement that enabled approval. LEQEMBI is the first Alzheimer’s disease treatment in Australia specifically designed to target toxic amyloid protofibrils as well as amyloid plaques, mechanisms that may influence downstream tau pathology and slow disease progression.

Dementia affects around 425,000 people in Australia (2024 estimates) and is projected to rise to nearly 1.1 million by 2065, with Alzheimer’s disease accounting for 60–70% of cases. Eisai leads global development and regulatory activities for lecanemab, with Eisai and Biogen co-commercializing and co-promoting the therapy worldwide. Eisai retains final decision-making authority in this collaboration.