BioArctic AB's (publ) partner Eisai announced that they have submitted a proposed Marketing Authorisation Variation to the European Medicines Agency (EMA) for a once every four weeks intravenous (IV) infusion maintenance dosing for lecanemab. In the EU, lecanemab is indicated for the treatment of patients with a clinical diagnosis of mild cognitive impairment (MCI) or mild dementia due to Alzheimer's disease (early Alzheimer's disease) who are apolipoprotein E e4 (ApoE e4) non-carriers or heterozygotes with confirmed amyloid pathology. Lecanemab is currently licensed as an IV infusion with a dosing regimen of once every two weeks (10 mg/kg).
Eisai's submission states that following the initial dosing regimen of Once every two weeks, after 18 months, patients will be transitioned to the maintenance dosing regimen of once every four weeks. Treatment with lecanemab should be discontinued once the patient progresses to moderate Alzheimer's disease. Lecanemab are the result of a long-standing collaboration between BioArctic and Eisai, and the antibody was originally developed by BioArctic based on the work of Professor Lars Lann felt and his discovery of the Arctic mutation in Alzheimer's disease.
It is a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) andinsoluble forms of amyloid-beta (Ab). Lecanemab is approved in 53 countries and is under regulatory review in 7 countries. Following the initial phase with treatment every two weeks for 18 months, intravenous (IV) maintenance dosing with treatment every four weeks is approved in the United Kingdom, China, the U.S. and other countries, and applications have been filed in 4 countries and regions.
In the U.S., Leqembi Iqlik(TM) is approved for subcutaneous dosing with an autoinjector for maintenance treatment of early Alzheimer's disease (AD). In November 2025, a rolling sBLA application to the U.S. FDA for the subcutaneous initiation dosing with Leqembi IqlIK was also completed and a new drug application for subcutaneous formulation of Leqembi was submitted in Japan. In December 2025, Lecanemab has been included in the "Commercial Insurance Innovative Drug List", recently introduced by the National Healthcare Security Administration (NHSA) of China.
In January 2026, Eisai's supplemental Biologics License Application regarding a subcutaneous starting dose with Leqembi IQLik was granted Priority Review by the US FDA with a May 24, 2026, PDUFA date. Since July 2020, Eisai's Phase 3 clinical study (AHEAD 3-45) with lecanemab in individuals with preclinical Alzheimer's disease meaning they are clinically normal and have intermediate or elevated levels of amyloid in their brains, is ongoing. The study was fully recruited in October 2024.
AHEAD 3-45 is a four-year study conducted as a public-private partnership between Eisai, Biogen and the Alzheimer's Clinical Trial Consortium that provides the infrastructure for academic clinical trials in AD and related dementias in the U.S., funded by the National Institute on Aging, part of the National Institutes of Health. Since January 2022, the Tau NexGen clinical study for Dominantly Inherited AD (DIAD), that is conducted by Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU), led by Washington University School of Medicine in St. Louis, is ongoing and includes lecanemab as the backbone anti-amyloid therapy.
