FDA Approves At-Home Weekly Injection for Early Alzheimer’s Treatment

The FDA has approved a new subcutaneous (SC) injectable formulation of Leqembi (lecanemab-irmb) for maintenance treatment of early Alzheimer's disease, allowing patients to switch from intravenous (IV) infusions to a once-weekly, at-home injection after completing 18 months of IV therapy. This approval is based on phase 3 trial data showing that SC dosing maintains clinical and biomarker benefits comparable to IV dosing, with fewer systemic reactions and manageable injection-site reactions. The injectable version, expected to be available in the U.S. starting October 6, 2025, is considered a more convenient treatment option, especially for patients with limited access to infusion centers or those who experience IV-related side effects. Meanwhile, the FDA is recommending earlier MRI monitoring for brain swelling (amyloid-related imaging abnormalities with edema, ARIA-E) in patients receiving Leqembi to better identify and mitigate serious risks, prompted by several early treatment deaths. Biogen, a leading developer of Leqembi alongside Eisai, continues to expand its Alzheimer's pipeline and production capacity, highlighting the drug's growing global availability and its significance in the treatment landscape. Overall, the new SC formulation and enhanced safety monitoring aim to improve patient adherence and safety in managing early Alzheimer's disease.