FDA Approves Leqembi Iqlik Subcutaneous Injection as Initiation Dose for Early Alzheimer's Disease

Eisai and Biogen announced that the FDA has approved a supplemental Biologics License Application for a once-weekly subcutaneous injection of lecanemab-irmb, (brand name Leqembi Iqlik), as an initiation dose for early Alzheimer's disease.¹ The approved initiation regimen delivers 500 mg once weekly as two 250 mg injections administered via autoinjector, each taking approximately 15 seconds to complete.¹ Leqembi Iqlik was already approved in the US for maintenance dosing at 360 mg weekly following 18 months of treatment; this approval extends subcutaneous administration to the start of treatment as well, meaning patients can now begin and continue lecanemab entirely via at-home injection, or switch between intravenous and subcutaneous administration at any point in the treatment course.¹

Lecanemab is a humanized IgG1 monoclonal antibody, the result of a research alliance between Eisai and BioArctic, that targets aggregated soluble protofibrils and insoluble fibril forms of amyloid-beta.¹ It is indicated for adults with mild cognitive impairment or mild dementia due to Alzheimer's disease, collectively referred to as early Alzheimer's disease, and has now been approved in 53 countries and regions.¹

What clinical data supported the approval?

FDA approval of the subcutaneous initiation dose was supported by sub-studies within the Phase III Clarity AD long-term extension, which followed the 18-month core study in patients with early Alzheimer's disease.¹ Once-weekly subcutaneous administration achieved drug exposure equivalent to intravenous dosing, supporting comparable clinical and biomarker benefit, including amyloid removal.¹ The rate of exposure-related adverse events, including ARIA-E (amyloid-related imaging abnormalities with edema), was expected to be comparable between subcutaneous and intravenous administration, and there was no increase in isolated ARIA-H, amyloid-related imaging abnormalities involving hemosiderin deposition without accompanying edema, for lecanemab compared with placebo.¹ Injection-related reactions occurred with subcutaneous dosing, most of which were localized rather than systemic.¹

Howard Fillit, MD, co-founder and chief science officer emeritus of the Alzheimer's Drug Discovery Foundation, said the approval marks a new era of Alzheimer's treatment, since for the first time patients and care partners have meaningful choice in how anti-amyloid treatment is delivered, and as treatment approaches continue to expand, innovations in drug delivery will play a critical role in improving access, supporting investigation of combination treatments, and advancing precision medicine in Alzheimer's care.¹

Why does at-home administration matter for Alzheimer's care specifically?

Anti-amyloid antibody therapy has historically required regular clinic-based intravenous infusions, a logistical burden that falls disproportionately on both patients experiencing cognitive decline and the care partners coordinating their treatment. Subcutaneous administration is intended to reduce the burden of clinic visits, decrease reliance on infusion center resources, cut treatment preparation and monitoring time, and preserve infusion capacity for patients who prefer or require intravenous therapy.¹ An autoinjector acceptability study cited in the announcement found that 94% of patients with early Alzheimer's disease and their care partners considered the Leqembi Iqlik device easy to use, with high satisfaction and confidence using it in an at-home setting.¹

This approval follows a three-month extension to the FDA's original review timeline for the subcutaneous starting-dose application, during which the agency requested additional information and classified the submission as a major amendment, though the companies noted the FDA had not raised approvability concerns during that extended review.² Eisai also plans to showcase real-world, at-home subcutaneous administration data for lecanemab, alongside Phase II findings for its investigational anti-tau antibody etalanetug, in a dedicated session at the Alzheimer's Association International Conference in London this month.³

What happens next?

Leqembi Iqlik as an initiation dose is expected to be available in the US in late August 2026, distributed through specialty pharmacy.¹ Eisai leads lecanemab's global development and regulatory submissions, with Eisai and Biogen co-commercializing the product and Eisai holding final decision-making authority.¹ With subcutaneous administration now approved across the full treatment course, from initiation through maintenance, the companies' next steps include expanding submissions for the subcutaneous formulation in other markets, including Japan and China, where regulatory applications are already under review.¹

References

1. FDA Approves LEQEMBI IQLIK® (lecanemab-irmb) Subcutaneous Injection as an Initiation Dose for Early Alzheimer's Disease. (2026 Jul 13). GlobeNewswire. https://investors.biogen.com/news-releases/news-release-details/fda-approves-leqembi-iqlikr-lecanemab-irmb-subcutaneous
2. Mirasol F. (2026 May 8). Eisai, Biogen Receive Extended FDA Review for Lecanemab Subcutaneous Starting Dose. BioPharm International. https://www.biopharminternational.com/view/eisai-biogen-receive-extended-fda-review-for-lecanemab-subcutaneous-starting-dose
3. Schoenthaler E. (2026 Jun 29). Eisai to Present Lecanemab SC Formulation and Etalanetug Tau Data at AAIC 2026. https://www.biopharminternational.com/view/eisai-to-present-lecanemab-sc-formulation-and-etalanetug-tau-data-at-aaic-2026