The U.S. Food and Drug Administration (FDA) has approved the Biologics License Application (BLA) for LEQEMBI® IQLIK™ (lecanemab-irmb), a once-weekly subcutaneous (SC) autoinjector intended for maintenance treatment of Alzheimer’s disease (AD). This device delivers 360 mg/1.8 mL (200 mg/mL) in approximately 15 seconds per injection.
It is indicated for patients with early AD, including those with mild cognitive impairment (MCI) or mild dementia due to AD. After completing 18 months of intravenous (IV) LEQEMBI treatment at a dose of 10 mg/kg every two weeks, the patients may either continue monthly IV LEQEMBI infusions or switch to weekly SC injections.
The approval was supported by sub-studies within the Phase 3 Clarity AD open-label extension trial, which evaluated SC dosing in early AD. It showed that both clinical and biomarker benefits were maintained after switching from IV LEQEMBI to LEQEMBI IQLIK.
Safety was evaluated in more than 600 patients. None of the 49 patients who received the weekly 360 mg SC dose after at least 18 months of IV therapy experienced systemic or local injection-site adverse events. Overall, SC dosing demonstrated a better safety profile than IV infusion. Systemic reactions occurred in less than 1% of SC patients vs. 26% of IV patients. Approximately 11% of SC patients had a mild local injection site reaction (i.e., redness, swelling), but these reactions were mild and did not require discontinuation.
The incidence of amyloid-related imaging abnormalities (ARIA) in SC patients was comparable to that of those who remained on IV therapy, as well as to the background levels in untreated patients. ARIA is usually asymptomatic, though it can occasionally be severe or fatal. Most cases occur within the first six months of IV initiation.
AD is a progressive neurodegenerative disease with no cure, characterized by amyloid beta (Aβ) and tau accumulation. LEQEMBI targets both the amyloid plaques and the toxic Aβ aggregates (protofibrils), which contribute to neuronal cell death and tau-related pathology. Because AD pathology is persistent, discontinuation of therapy can lead to reintensification of disease biomarkers. Therefore, continuous maintenance dosing, either weekly SC or monthly IV, is necessary to sustain the therapeutic benefits and slow progression.
In the Clarity AD confirmatory study, patients treated with IV lecanemab every bi-weekly demonstrated better than placebo by -0.45 point on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) scale at 18-month follow-up (P=0.00005). The difference in CDR-SB scores represents a clinically meaningful preservation of independence of daily life. At four years, lecanemab reduced cognitive decline by -1.75 points compared with ADNI patients and -2.17 points compared with the BioFINDER cohort, underscoring durable benefit.
The SC autoinjector provides significant benefits for both the patients and healthcare systems. A human factors study established that the device can be used safely and effectively in the home setting. The SC autoinjector provides many benefits, including shortened administration time, a reduction in dependence on infusion centers for patients and caregivers, and greater flexibility for healthcare providers to allocate infusion capacity to newly diagnosed patients. This new delivery model is expected to improve AD care access, reduce the resource burden, and enhance quality of life for patients and caregivers.
LEQEMBI IQLIK is scheduled for launch in the U.S. on October 6, 2025. Eisai is leading the global development and regulatory efforts with Eisai and Biogen co-commercializing the therapy.
The FDA approval of LEQEMBI IQLIK represents a major milestone in the management of AD, offering early-stage patients a convenient, effective, and safer maintenance therapy that can be administered at home. This innovation has the potential to transform long-term AD care and significantly improve patient outcomes.
References: Eisai Global. FDA Approves LEQEMBI® IQLIK™ (lecanemab-irmb) Subcutaneous Injection for Maintenance Dosing for the Treatment of Early Alzheimer’s Disease. Published August 30, 2025. Accessed September 8, 2025. FDA Approves LEQEMBI® IQLIK™ (lecanemab-irmb) Subcutaneous Injection for Maintenance Dosing for the Treatment of Early Alzheimer’s Disease | News Release：2025 | Eisai Co., Ltd.
