FDA Approves Leqembi for At-Home Maintenance Treatment of Alzheimer Disease

The US Food and Drug Administration (FDA) has approved Leqembi IQLIK (lecanemab), for self-administered injection for maintenance treatment of Alzheimer disease in patients with mild cognitive impairment (MCI) or mild dementia.¹ Leqembi, developed by Esai and Biogen, is the only treatment for Alzheimer disease that can be administered subcutaneously at home using an autoinjector.

The currently available Leqembi is administered intravenously (IV), which requires patients to visit an infusion center every 2 weeks, but this new at-home autoinjector is designed to simplify this process and allow maintenance dosing self-administered by patients.

The FDA’s approval cited data from the Phase 3 Clarity AD open-label extension study, which indicated that the weekly subcutaneous dose effectively cleared amyloid plaque.² The FDA's review of the subcutaneous administration focused on data from the open-label extension of the Clarity AD study and utilized predictive modeling. The companies developing this treatment aimed to show that the at-home formulation has a comparable safety and efficacy profile to the already approved IV version. The original Clarity AD study, which led to the drug's initial approval, showed that Leqembi slowed clinical decline by 27% over 18 months.³

This decision follows the FDA's previous traditional approval of the intravenous form of Leqembi in July 2023, which made it the first and only FDA approved anti-amyloid treatment shown to slow cognitive and functional decline in patients with early Alzheimer disease.⁴ The Biologics License Application (BLA) for Leqembi subcutaneous autoinjector was accepted by the FDA in January 2025.⁵ The new subcutaneous option seeks to provide a more convenient administration method while preserving the drug’s clinical benefits. The new at-home autoinjector is intended to be a simple, 15-second injection for weekly maintenance, designed for patients who have completed the initial biweekly IV treatment phase. The FDA also recently added to recommendations for the already approved administration of Leqembi, recommending additional early magnetic resonance imaging scans before the third infusion in an effort to identify issues with amyloid-related imaging abnormalities with edema.⁵

John J. Miller, MD, editor in chief of Psychiatric Times, said the decision, “is a bold and welcome move by the FDA,” noting the new form of administration “should significantly increase access, increase continued maintenance treatment, and should result in decreased cost.”

Leqembi is a humanized monoclonal antibody designed to target and clear both soluble amyloid beta protofibrils and insoluble amyloid plaques, key features of Alzheimer disease. Leqembi treats Alzheimer disease by continuously clearing protofibrils and rapidly clearing plaque. With continuous administration, the drug clears highly toxic protofibrils which can continue to cause neuronal injury even after amyloid-β plaque has been cleared from the brain. Long-term data presented at the Alzheimer's Association International Conference in 2024 suggest that early and continuing treatment may prolong the benefit of this treatment even after plaque is cleared from the brain.

Helen Lavretsky, MD, MS, said in an exclusive statement to Psychiatric Times, “The introduction of injectable Leqembi will significantly impact clinicians by increasing demand, improving treatment convenience, and altering administration protocols and monitoring procedures. The new subcutaneous autoinjector is expected to reduce the burden on patients and caregivers, but also creates new logistical and safety considerations for healthcare providers. Greater convenience is expected to lead to higher patient adherence to the long-term therapy, which requires consistent use to slow cognitive decline.”

Leqembi is estimated to be available October 6, 2025, in the US.

References

1. FDA Approves LEQEMBI® IQLIK™ (lecanemab-irmb) Subcutaneous Injection for Maintenance Dosing for the Treatment of Early Alzheimer's Disease. Biogen press release. August 29, 2025. Accessed August 30, 2025. https://investors.biogen.com/news-releases/news-release-details/fda-approves-leqembir-iqliktm-lecanemab-irmb-subcutaneous

2.Irizarry M, Li D, Dhadda S, et al. Preliminary update on lecanemab safety in Clarity AD open-label extension, including subcutaneous formulation. Presented at: CTAD conference; October 24-27, 2023; Presentation 4

3. Cohen S, van Dyck CH, Gee M, et al. Lecanemab Clarity AD: quality-of-life results from a randomized, double-blind phase 3 trial in early Alzheimer's disease. J Prev Alzheimers Dis. 2023;10(4):771-777.

4. O’Brien E. FDA grants traditional approval to Leqembi for the treatment of Alzheimer disease. Psychiatric Times. July 6, 2023.https://www.psychiatrictimes.com/view/fda-grants-traditional-approval-to-leqembi-for-the-treatment-of-alzheimer-disease

5. FDA to recommend additional, earlier MRI monitoring for patients with Alzheimer’s disease taking Leqembi (lecanemab). US Food and Drug Administration. August 28, 2025. Accessed August 29, 2025. https://www.fda.gov/drugs/drug-safety-and-availability/fda-recommend-additional-earlier-mri-monitoring-patients-alzheimers-disease-taking-leqembi-lecanemab?utm_medium=email&utm_source=govdelivery

6. Kuntz L. FDA accepts biologics license application for Lecanemab-irmb. Psychiatric Times. January 14, 2025. https://www.psychiatrictimes.com/view/fda-accepts-biologics-license-application-for-lecanemab-irmb