Swedish research-based biopharma company BioArctic AB (STO: BIOA-B) on Friday said its Japanese partner Eisai Co Ltd (TYO: 4523) has launched Leqembi Pen, the subcutaneous formulation of lecanemab, in Japan for the treatment of early Alzheimer's disease.

Japan is the second country after the US where the subcutaneous formulation has been launched.

The product was approved in Japan on 16 September 2026 and has been added to the country's National Health Insurance Drug Price List. BioArctic said it is the first and only anti-amyloid treatment in Japan that can be administered at home.

Leqembi Pen uses an autoinjector and offers a once-weekly subcutaneous option alongside intravenous administration every two weeks in a medical facility. The approved dose is 500 mg once weekly, given through two pens.

Home administration may reduce clinic visits and the use of healthcare resources associated with intravenous treatment. After education and training, patients can self-administer, or a family member or care partner can do so under physician guidance.

As with intravenous treatment, MRI monitoring for amyloid-related imaging abnormalities is required before treatment starts and at specified points thereafter.