PR Newswire·Nov 13, 2026, 2:11 AM ET

Leqembi® Pen subcutaneous treatment launched in Japan

BioArctic partner Eisai launched Leqembi Pen, a subcutaneous formulation of lecanemab, in Japan on November 13, 2026.
Japan is the second country following the US where the subcutaneous formulation of Leqembi has been launched.
Leqembi Pen received approval in Japan on September 16, 2026, & was included in the National Health Insurance Drug Price List.
Leqembi Pen is the first anti-amyloid treatment in Japan enabling at-home administration via an autoinjector.
The approved regimen involves a 500 mg once-weekly dose administered through two pens as an alternative to bi-weekly intravenous treatment.
At-home administration offers flexibility, potentially reducing clinic visits & healthcare resource use associated with IV administration.
Patients or care partners may self-administer the treatment after training, under physician guidance, similar to IV protocols.
MRI monitoring for amyloid-related imaging abnormalities remains required prior to initiation & at specified intervals.
Leqembi is approved in 53 countries & subcutaneous initiation was approved in China & Japan in September 2026.
BioArctic maintains a long-term collaboration with Eisai since 2005, with BioArctic holding commercial rights in the Nordic region.
BioArctic is entitled to sales milestone payments & royalties on global sales but bears no development costs for lecanemab.
Eisai leads global clinical development, regulatory approval, & commercialization of the drug.