FDA Approves Leqembi IQLIK (lecanemab-irmb) Subcutaneous Injection as an Initiation Dose for Early Alzheimer’s Disease – Eisai + Biogen

Eisai Co., Ltd. and Biogen Inc. announced that the FDA has approved a supplemental Biologics License Application (sBLA) for a once-weekly lecanemab-irmb subcutaneous injection (brand name: Leqembi IQLIK) as an initiation dose for the treatment of early Alzheimer’s disease.
Leqembi IQLIK is administered via an autoinjector, introducing a convenient alternative to intravenous (IV) dosing from the start of treatment. For initiation, the approved regimen is 500 mg given once weekly as two 250 mg injections, each delivered in approximately 15 seconds. Leqembi IQLIK may also be used for maintenance dosing at 360 mg once weekly after 18 months of IV or subcutaneous treatment. Throughout the entire treatment course – from initiation through maintenance – patients may receive Leqembi either as IV infusion or as subcutaneous (SC) injection with Leqembi IQLIK. Patients may also switch from IV to SC administration, or vice versa, providing greater convenience and flexibility in Leqembi administration.

Leqembi is indicated in the United States for adults with mild cognitive impairment (MCI) or mild dementia due to Alzheimer’s disease, collectively referred to as early Alzheimer’s disease. MCI due to AD is the earliest symptomatic stage of Alzheimer’s disease and can appear with subtle symptoms such as forgetfulness, confusion, or feeling at a loss for words.

Clinical Data Supporting FDA Approval of Subcutaneous Initiation Dosing

The FDA approval of Leqembi IQLIK as an initiation dose is supported by a comprehensive clinical data package evaluating SC administration of lecanemab across multiple studies and a range of dosing regimens. Sub-studies within the Phase 3 Clarity AD long-term extension (LTE), following the 18-month core study in individuals with early Alzheimer’s disease, showed:

i) Once-weekly subcutaneous administration achieved exposure equivalent to intravenous dosing, supporting similar clinical (efficacy) and biomarker (amyloid removal) benefits.

ii) The rate of exposure-related adverse events such as ARIA-E with SC administration is expected to be comparable with IV administration. There was no increase in isolated ARIA-H (i.e., ARIA-H in patients who did not also experience ARIA-E) for Leqembi compared to placebo.

iii) The overall safety profile of SC administration was generally similar to intravenous administration. Injection-related reactions were observed with subcutaneous Leqembi, most of which were localized, while systemic reactions were less frequently observed.

“The approval of Leqembi IQLIK for initiation dosing marks a new era of Alzheimer’s treatments,” said Howard Fillit, MD, Co-Founder and Chief Science Officer Emeritus of the Alzheimer’s Drug Discovery Foundation (ADDF). “For the first time, patients and their care partners have meaningful choice in how anti-amyloid treatment is delivered. As treatment approaches continue to expand, innovations in drug delivery will play a critical role in improving access to therapies, supporting the investigation of potential combination treatments, and advancing a precision medicine approach to Alzheimer’s care.”

Expanding Treatment Flexibility Across the Alzheimer’s Disease Care Pathway
The approval of Leqembi IQLIK as a subcutaneous initiation dose provides patients and care partners with the only at-home administration option throughout the Alzheimer’s disease treatment journey which could support access and delivery of care across healthcare settings. Subcutaneous administration may:

i) Reduce the burden of clinic visits currently associated with anti-amyloid therapy for patients and care partners

ii) Reduce reliance on infusion and associated healthcare resources

iii) Decrease treatment preparation and administration time, and nursing monitoring requirements

iv) Preserve infusion capacity for patients who prefer or require intravenous therapy

Insights from an autoinjector acceptability study indicated that 94% of patients with early Alzheimer’s disease and their care partners found the Leqembi IQLIK device easy to use, with high levels of satisfaction and confidence in using it in an at-home setting.

Leqembi IQLIK for initiation dosing is expected to be available in late August 2026 in the U.S. Patients will receive Leqembi IQLIK from a specialty pharmacy.

Eisai serves as the lead for lecanemab’s development and regulatory submissions globally with Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.