LEQEMBI(R) Pen (Subcutaneous Formulation of LEQEMBI(R)) Approved in Japan for the Treatment of Early Alzheimer’s Disease

TOKYO and CAMBRIDGE, Mass., September 18, 2026 – (JCN Newswire) – Eisai Co., Ltd. and Biogen Inc. (Nasdaq: BIIB), revealed today that “LEQEMBI ® Pen”, the subcutaneous (SC) solution of the anti-amyloid beta (Aβ) protofibril antibody “LEQEMBI ®” (brand, generic name: lecanemab) has actually been authorized in Japan as a brand-new path of administration.

LEQEMBI Pen is an autoinjector formula that allows administration by a care partner or client self-administration, with 2 pens (amounting to 500 mg) administered when weekly. With this approval, LEQEMBI treatment now provides a brand-new choice of once-weekly SC administration in your home *, in addition to intravenous (IV) administration every 2 weeks in a medical facility setting.

LEQEMBI Pen might lower the time needed for anti-amyloid treatment administration compared to IV infusions (approximate injection time of 15 seconds per injection). In addition, at-home administration might minimize the problem of center gos to for clients and their care partners and offer higher versatility in treatment, permitting clients to make treatment options that much better fit their way of lives, consisting of less restraints on heading out and taking a trip. The enhanced benefit and versatility of treatment with LEQEMBI is anticipated to lower barriers to starting and continuing treatment with LEQEMBI. LEQEMBI Pen likewise has the prospective to minimize health care resources associated with IV dosing, such as nurse tracking, as well as preserving infusion capability. These functions are anticipated to add to more simplifying the general Alzheimer’s illness (ADVERTISEMENT) treatment path. For amyloid-related imaging problems (ARIA) tracking, just like IV administration, brain magnetic resonance imaging (MRI) is carried out prior to starting treatment and at defined time points after treatment initiation.

Advertisement is a progressive, ruthless illness with Aβ and tau as trademarks that is brought on by a constant underlying neurotoxic procedure driven by protofibrils that starts before amyloid plaque build-up and continues after plaque elimination.1,2,3 Only LEQEMBI battles advertisement in 2 methods– targeting both protofibrils and amyloid plaque.

This marks the 3rd nation internationally to authorize LEQEMBI SC solution. This approval is based upon the incorporated outcomes of information and associated modeling and simulation from the 18-month core research study of the Phase 3 Clarity advertisement research study of LEQEMBI in clients with moderate cognitive disability (MCI) due to advertisement or moderate advertisement dementia (jointly described as early advertisement), in addition to numerous SC administration sub-studies in its subsequent long-lasting extension research study (LTE). Once-weekly administration of SC solution 500 mg showed comparable direct exposure to IV administration as soon as every 2 weeks and supported the expectation that the SC formula offers effectiveness similar to that of the IV solution. The total security profile of SC administration was usually comparable to that of IV administration, while systemic injection/infusion-related responses were observed less regularly with SC administration (1.4%)** than with IV administration.

Eisai works as the lead for lecanemab’s advancement and regulative submissions worldwide, with Eisai and Biogen co-commercializing and co-promoting the item and Eisai having last decision-making authority.

* At-home, self-administration utilizing LEQEMBI Pen will be possible after it is noted in the injectable drug list designated by the Minister of Health, Labour and Welfare that medical insurance medical professional can administer (or recommend), following consideration and approval by the Central Social Insurance Medical Council, in concept within 60 days after approval. In addition, the following points are specified to be observed when self-administering.

– When starting administration, treatment needs to be administered by a doctor or under the direct guidance of a doctor at a medical center.

– With regard to the applicability of self-administration, the suitability thereof will be thoroughly thought about, and just after supplying extensive education and training, and verifying that the client or household member/caregiver comprehends the dangers connected with administration of this drug and how to react to them, which the client or household member/caregiver has the ability to dependably administer it themselves, will self-administration be executed under the management and assistance of a doctor.

** Incidence in individuals freshly started on lecanemab treatment by means of SC administration, based upon scientific information gotten from once-weekly subcutaneous administration of lecanemab 720 mg utilizing vial formulas.

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To find out more: https://www.eisai.com/news/2026/news202652.html

Subject: Press release summary