Eisai, Biogen scoop up subQ Leqembi starter‑dose nod – FDA greenlights subcutaneous lecanemab initiation for early Alzheimer’s disease

Biogen and Eisai have received FDA approval for a subcutaneous (under-the-skin) formulation of Leqembi (lecanemab) as a starter dose for early Alzheimer’s disease.

The new subcutaneous version, branded LEQEMBI IQLIK®, is administered weekly via an autoinjector and can be used both to initiate treatment and for ongoing maintenance dosing.

This approval, granted in mid-July 2026, allows patients to start Leqembi therapy with a subcutaneous injection rather than the previous intravenous (IV) infusion, and to continue the entire course of treatment at home, which is a first among anti‑amyloid Alzheimer’s therapies.

Clinical data from the Phase 3 Clarity AD trial and related sub‑studies showed that the weekly 500 mg subcutaneous dose achieves drug exposure comparable to the IV initiation regimen, with similar clinical and biomarker effects and a comparable safety profile.

Common side effects include localized injection‑site reactions (erythema, swelling, pain) and some systemic reactions such as headache and fatigue, mostly at the first dose; more serious risks include ARIA (amyloid‑related imaging abnormalities) and hypersensitivity reactions such as anaphylaxis.

Leqembi IQLIK for initiation dosing is expected to be available in the U.S. starting in late August 2026, dispensed through specialty pharmacies, and can be used either from the outset or as an option after 18 months of IV therapy.