NextFin news, Australia's Therapeutic Goods Administration (TGA) approved the Alzheimer's drug lecanemab, marketed as LEQEMBI, on Thursday, September 25, 2025, for use in adults diagnosed with mild cognitive impairment or mild dementia due to Alzheimer's disease (early Alzheimer's).
The approval follows a review process that addressed earlier safety concerns, including risks of amyloid-related imaging abnormalities (ARIA), such as brain swelling and bleeding. Lecanemab is indicated for patients who are either non-carriers or heterozygous carriers of the ApoE ε4 gene, a genetic factor influencing treatment safety.
Lecanemab is a humanized monoclonal antibody targeting toxic amyloid-beta protofibrils and plaques in the brain, aiming to slow cognitive decline. The approval was based primarily on Phase 3 clinical trial data from Eisai's global Clarity AD study, which showed a 33% reduction in clinical decline over 18 months compared to placebo in the indicated population.
The drug's developers, Eisai Co., Ltd. and Biogen Inc., co-commercialize and co-promote lecanemab, with Eisai holding final decision-making authority. The TGA's approval came after Eisai requested a review by the Administrative Review Tribunal following an initial rejection in February 2025.
Despite regulatory approval, access to lecanemab in Australia remains limited due to its high cost and the need for careful patient monitoring by healthcare professionals to manage potential side effects. Dementia Australia CEO Professor Tanya Buchanan emphasized the importance of timely diagnosis and informed patient choice, noting that lecanemab is not a cure but a treatment option for early-stage Alzheimer's.
According to the Australian Institute of Health and Welfare, dementia is now the leading cause of death in Australia, with approximately 425,000 people living with dementia in 2024, projected to rise to nearly 1.1 million by 2065. Alzheimer's disease accounts for 60-70% of dementia cases.
The TGA recommends confirming beta amyloid presence consistent with Alzheimer's disease before initiating treatment. Common adverse reactions reported include infusion-related reactions, ARIA-E (edema), ARIA-H (microhemorrhages), and headache. Serious ARIA events were rare but require monitoring.
Lecanemab has been approved in 50 countries and is under regulatory review in several others. In Australia, the drug joins Donanemab (Kisunla), approved earlier in 2025, as part of emerging treatment options for early Alzheimer's disease.
For more information, the TGA announcement and product information are publicly available, and Eisai and Biogen provide detailed clinical data and safety profiles on their official websites.
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