The US FDA approved a supplemental Biologics License Application for Leqembi Iqlik (lecanemab-irmb) subcutaneous injection as an initiation dose for early Alzheimer’s disease, marking the first time an anti-amyloid therapy can be self-administered at home from the start of treatment. Eisai and Sweden-based BioArctic AB (Nasdaq Stockholm: BIOA B) announced the decision, which extends the existing Leqembi franchise beyond intravenous infusion into a fully subcutaneous treatment course.
The approved regimen for initiation is 500 mg once weekly, delivered as two 250 mg injections via autoinjector, each taking approximately 15 seconds to administer. Leqembi Iqlik was already approved for subcutaneous maintenance dosing at 360 mg once weekly following 18 months of intravenous or subcutaneous treatment. Patients can now receive Leqembi subcutaneously throughout treatment or switch between intravenous and subcutaneous dosing as clinically appropriate.
The sBLA was supported by data from sub-studies within the Phase III Clarity AD long-term extension, conducted in individuals with early Alzheimer’s disease following the 18-month core study. Pharmacokinetic data demonstrated exposure comparable to intravenous dosing, with similar amyloid plaque removal and a safety profile consistent with the IV formulation. Injection-site reactions were predominantly mild and localized. As previously reported, the FDA had extended its review of the sBLA by three months ahead of the final decision.
Lecanemab is a humanized IgG1 monoclonal antibody that selectively binds soluble amyloid-β protofibrils and fibrillar amyloid, promoting immune-mediated clearance of amyloid plaques. The subcutaneous formulation delivers the same active molecule via autoinjector, with pharmacokinetic bridging data supporting equivalent systemic exposure and, by extension, comparable clinical and biomarker effects to the established intravenous regimen.