New Leqembi Autoinjector Data Show Comparable Efficacy and Safety

Swedish company BioArctic AB and its partner Eisai presented new data at the Alzheimer's Association International Conference (AAIC) 2026 in London, detailing the Leqembi (lecanemab) subcutaneous autoinjector (SC-AI) formulation. The findings indicate that the autoinjector offers efficacy and safety comparable to intravenous (IV) administration for patients with early Alzheimer's disease.

The data revealed that a once-weekly 500 mg SC-AI dose achieved similar drug exposure to the approved IV initiation regimen given every two weeks. This supports the expectation of similar clinical efficacy and safety, irrespective of the administration route. The subcutaneous option may provide a more convenient at-home treatment alternative to IV infusions, thereby improving access and flexibility for patients.

The study demonstrated that amyloid removal, clinical efficacy measures, and the incidence of ARIA-E (amyloid-related imaging abnormalities-edema) were driven by lecanemab exposure rather than the route of administration. While injection-related reactions were observed, they were predominantly localized and mild, with infrequent systemic reactions. Additionally, a low incidence of anti-drug antibodies did not appear to affect treatment outcomes.

Real-world evidence from two US treatment centers supports the benefits of subcutaneous administration. Patients receiving SC treatment showed slower cognitive decline and reported high satisfaction with the therapy. These findings reinforce the potential of the subcutaneous Leqembi formulation to enhance long-term treatment pathways and improve the patient experience.