FDA to Review Subcutaneous Lecanemab Treatment as a Starting Dose for Early Alzheimer’s

Eisai (Tokyo, Japan) and Biogen (Cambridge, MA) have initiated the rolling submission of a supplemental Biologics License Application (sBLA) to the Food and Drug Administration (FDA) for Leqembi IQLIK (lecanemab-irmb; Eisai, Tokyo, Japan; Biogen, Cambridge, MA). If approved, the sBLA would permit once-weekly treatment with Leqembi IQLIK as a starting dose for people with early Alzheimer disease (AD), which follows the FDA’s decision to approve Leqembi IQLIK for maintenance dosing. According to a statement from Eisai, the FDA has already granted Leqembi IQLIK Fast Track Designation as a starting dose.

The application is supported by data from sub-studies from the Phase 3 Clarity AD (NCT03887455) open-label extension, which evaluated Leqembi IQLIK treatment across multiple dosing regimens in individuals who completed the 18-month core study. If approved, the new formulation would provide an alternative to the current starting dose of biweekly IV infusion therapy, enabling patients and caregivers to choose between at-home injections or in-clinic dosing.

The autoinjector delivers 250 mg of Leqembi IQLIK subcutaneously per injection, with 2 injections required for the weekly 500 mg starting dose. Each injection takes about 15 seconds to administer.

Source: Eisai Inc. Eisai initiated rolling supplemental Biologics License Application to the U.S. FDA for LEQEMBI® IQLIK™ (lecanemab-irmb) as a subcutaneous starting dose for the treatment of early Alzheimer’s disease under Fast Track Status. Eisai.com. Published September 3, 2025. Accessed September 4, 2025. https://www.eisai.com/news/2025/news202560.html