U.S. FDA approves at‑home starter dose of Leqembi for Alzheimer’s

The U.S. Food and Drug Administration approved a subcutaneous, at‑home starter dose of Leqembi (lecanemab), the Alzheimer’s drug developed by Eisai and Biogen. The new formulation lets patients or caregivers administer the first injection themselves, rather than receiving an intravenous infusion in a clinic. Biogen’s shares rose about 4.5% after the announcement.

Leqembi, already authorized for adults with early Alzheimer’s disease, targets amyloid‑beta plaques in the brain. The FDA based its decision on earlier trials that showed the subcutaneous version achieved equivalent amyloid reduction and similar safety profiles to the IV version, though it was not tested in a separate large outcomes trial. Injection‑site reactions such as redness or swelling may occur.

Data presented at the Alzheimer’s Association International Conference 2026 indicated that weekly 500 mg subcutaneous dosing achieved bioequivalence to the approved IV regimen, supporting comparable efficacy and safety. The at‑home option is expected to improve patient access and differentiate Leqembi from competing therapies that require infusions.