New clinical and real-world data support a subcutaneous treatment pathway from initiation through maintenance treatment, offering dosing convenience for patients and care partners
TOKYO and CAMBRIDGE, Mass., July 12, 2026 (GLOBE NEWSWIRE) -- Eisai Co., Ltd. and Biogen Inc. (Nasdaq: BIIB) announced today that new data presented at the Alzheimer's Association International Conference® (AAIC®) 2026 in London support that the LEQEMBI® (lecanemab) subcutaneous autoinjector (SC-AI) formulation offers efficacy and safety comparable to intravenous (IV) administration for people with early Alzheimer's disease (AD). The data was featured during the "Lecanemab Subcutaneous Formulation in Early Alzheimer's Disease: Emerging Clinical Evidence and Practical Use Considerations" Developing Topics Session #1-32-FRS-C.
AD is a chronic, progressive disease that requires ongoing treatment. LEQEMBI is an early AD treatment that targets the underlying pathology of the disease, helping to slow cognitive decline and loss of daily functioning. The lecanemab subcutaneous auto-injector (SC-AI) was developed to provide a more convenient alternative to intravenous (IV) dosing from the start of treatment.
Key Findings
This session presented data from the lecanemab SC-AI development program in early Alzheimer's disease, including pharmacokinetic (PK), pharmacodynamic (PD), efficacy, safety and real-world patient and care partner experience findings. Results showed that once-weekly 500 mg SC-AI achieved drug exposure similar to the approved intravenous (IV) initiation regimen (10 mg/kg every two weeks), supporting the expectation of similar clinical efficacy and safety, independent of the route of administration.
The subcutaneous dosing option may offer a convenient at-home alternative to IV infusion which could support access and delivery of care across healthcare settings.
Data Showed
Bioequivalence Achieved: Once-weekly 500 mg SC-AI demonstrated bioequivalence to the IV initiation regimen (10 mg/kg every two weeks), with an exposure ratio of 104% (90% confidence interval [CI]: 99.1%–109%). Exposure remained consistent across body weight quartiles, demonstrating a stable pharmacokinetic profile in a broad patient population.
Efficacy Driven by Exposure, Not Route of Administration: Amyloid removal measured by amyloid PET, clinical efficacy measured by CDR-SB, and the incidence of ARIA-E were driven by lecanemab exposure rather than route of administration. The 500 mg SC-AI initiation regimen achieved exposure comparable to the IV initiation regimen, supporting the expectation of a comparable efficacy and safety profile despite the different route of administration.
Consistent Results Across Patient Populations: The 500 mg SC-AI initiation regimen demonstrated consistent exposure, amyloid clearance as measured by amyloid PET, clinical efficacy and safety across body weight groups. In addition, amyloid clearance and clinical outcomes were not meaningfully affected by body weight, supporting the appropriateness of a fixed-dose regimen.
Flexible switching between IV and SC administration: Patients may also switch from IV to SC administration, or vice versa, and if a dose is missed patients can take it the next day or up to day six providing greater convenience and flexibility in LEQEMBI administration.