Subcutaneous Lecanemab Approved by FDA for Maintenance Dosing in Alzheimer Disease

The Food and Drug Administration (FDA) has approved the Biologics License Application (BLA) for a subcutaneous formulation of lecanemab called Leqembi IQLIK (lecanemab-irmb; Eisai, Tokyo, Japan; Biogen, Cambridge, MA) for maintenance dosing for the treatment of people with early Alzheimer disease (AD), including those with mild cognitive impairment (MCI) or mild dementia. Leqembi IQLIK is administered in approximately 15 seconds via autoinjector (200 mg/1.8 mL) once weekly and is an option for people who have already completed 18 months of intravenous (IV) treatment.

The FDA’s decision to approve Leqembi IQLIK was based on data from the phase 3 Clarity AD (NCT03887455) open-label extension (OLE) study. Safety was evaluated in more than 600 participants across different subcutaneous dosing regimens.

• People who switched to subcutaneous Leqembi IQLIK maintenance dosing after 18 months of IV treatment were shown to have maintained clinical and biomarker benefits comparable to individuals who continued IV dosing.
• Among 49 individuals who received Leqembi IQLIK 360 mg maintenance dosing after 18 months of IV treatment, no systemic or local injection-related adverse events were reported.
• Rates of amyloid-related imaging abnormalities (ARIA) were similar between those who received subcutaneous Leqembi IQLIK and IV Leqembi treatment, which were consistent with background ARIA rates in untreated individuals.

In a statement from Eisai and Biogen, the companies note the importance of ongoing treatment, as the cessation of anti-amyloid therapy is associated with the reaccumulation of AD biomarkers and a return to rates of clinical decline seen in those treated with placebo in clinical studies. The companies state that subcutaneous Leqembi IQLIK may shorten treatment time by enabling at-home therapy without visiting an infusion center. Eisai and Biogen cite October 6, 2025 as a launch date for Leqembi IQLIK in the United States, with financial support programs to assist patients and care partners in accessing the therapy.

Leqembi IQLIK’s label includes a Boxed Warning for ARIA.

Source: Eisai Inc. FDA approves LEQEMBI® IQLIK™ (lecanemab-irmb) subcutaneous injection for maintenance dosing for the treatment of early Alzheimer's disease. PRNewswire.com. Published 29 August 2025. Accessed 2 September 2025. https://prnmedia.prnewswire.com/news-releases/fda-approves-leqembi-iqlik-lecanemab-irmb-subcutaneous-injection-for-maintenance-dosing-for-the-treatment-of-early-alzheimers-disease-302542371.html