Launches in the EU: Novel Alzheimer's antibody - Lecanemab
Lecanemab, a humanised IgG1 antibody developed by BioArctic, and Donanemab, developed by Eli Lilly, are two promising treatments for early Alzheimer's Disease (AD) that have recently made headlines.
Lecanemab, marketed under the brand name Leqembi, received accelerated approval from the US Food and Drug Administration (FDA) in January 2023 and full market authorization in July 2023. The European Commission (EC) approved its use in April 2025 for treating adult patients with mild cognitive impairment (MCI) or mild dementia due to early AD, specifically in ApoE ε4 non-carriers or heterozygotes with confirmed amyloid pathology. Eisai holds the rights for commercialisation of Lecanemab worldwide, excluding the Nordic region, where BioArctic retains the rights.
Lecanemab works by targeting soluble Aβ protofibrils, promoting their clearance via microglia-mediated phagocytosis and inhibiting further aggregation into fibrillar plaques. However, its registration in Australia was rejected due to safety concerns related to ARIA-E and H, cerebral oedema/effusion or microhemorrhages, which occurred in 9% and 13% of patients in the pivotal CLARITY-AD trial, respectively.
Analysts predict peak revenues of US $9.9 billion for Lecanemab by 2034. In the EU, treatment with Lecanemab reduced clinical decline on the global cognitive and functional scale, Clinical Dementia Rating - Sum of Boxes (CDR-SB), by 31% at 18 months.
Donanemab, also known as Kisunla, received FDA market approval in the US in July 2024. The EMA recommended conditional EU approval for Donanemab in July 2025. Donanemab targets N-terminal pyroglutamate-modified Aβ (pGlu-Aβ) species within amyloid plaques. Homozygotous carriers are excluded from Donanemab treatment due to a higher risk of ARIA-E and -H.
Analysts estimate peak revenues of US $6.4 billion for Donanemab by 2032. The development of both Lecanemab and Donanemab can be traced back to significant scientific discoveries. Lecanemab was based on the work of Professor Lars Lannfelt and the discovery of the Arctic mutation in Alzheimer's disease, while Donanemab's development was undertaken by Eli Lilly.
In the CLARITY-AD clinical trial, the primary endpoint for Lecanemab was the global cognitive and functional scale, CDR-SB. Treatment with Lecanemab in the indicated EU population showed a significant reduction in clinical decline on CDR-SB.
As these treatments continue to make progress, they offer hope for those affected by early Alzheimer's disease and their families.
