Stockholm – October 30, 2026 -- Eisai will present five years of Clarity AD data on lecanemab (Leqembi) at the Clinical Trials on Alzheimer's Disease (CTAD) conference in Boston, November 16-19, 2026, according to its partner BioArctic AB (Nasdaq Stockholm: BIOA B). The dataset spans the core and long-term extension phases and is one of the longest follow-up sets reported to date for an approved anti-amyloid Alzheimer's therapy.
LEADER study tests lecanemab in US clinical practice three years after approval
A symposium on Wednesday, November 18, 11:00-11:40 AM ET, will cover the retrospective, multicenter LEADER study. The study draws on real-world data from different types of US treatment centers, three years after FDA approval.
Three analyses are scheduled: utilization and outcomes from initiation through maintenance therapy, sex-based outcomes, and at-home subcutaneous administration.
Oral sessions address ARIA safety rates and alpha-synuclein co-pathology
Additional oral presentations will examine real-world safety, including ARIA rates and safety profiles reported across multiple countries. Another will cover lecanemab treatment and alpha-synuclein co-pathology in the Clarity AD cerebrospinal fluid (CSF) substudy.
Eisai's posters will address effectiveness, safety, treatment persistence and subcutaneous administration. Further posters will cover CSF protein changes, biomarker-based diagnosis, long-term outcomes and disease biology. BioArctic will present its own poster on the binding profile of lecanemab.
Leqembi is approved in 53 countries as subcutaneous and maintenance options expand
Leqembi is approved in 53 countries and under regulatory review in six countries and regions. IV maintenance dosing every four weeks, after 18 months of treatment every two weeks, is approved in nine countries and regions, including the US, Japan, China and the UK. Applications are filed in eleven more.
In the US, Leqembi Iqlik is approved as a subcutaneous autoinjector for both starting and maintenance doses in early Alzheimer's disease. Subcutaneous initiation treatment won approval in China and Japan in September 2026, and applications are under review in four countries.
BioArctic carries no lecanemab development costs and earns royalties on global sales
Eisai is responsible for clinical development, market approval applications and commercialization. BioArctic has no development costs for lecanemab in Alzheimer's disease. It is entitled to sales milestone payments and royalties on global sales, and has the right to co-commercialize in the Nordic region with Eisai.
The Phase 3 AHEAD 3-45 study in preclinical Alzheimer's disease has run since July 2020 and was fully recruited in October 2024. It is a four-year public-private partnership between Eisai, Biogen and the Alzheimer's Clinical Trial Consortium, funded by the National Institute on Aging. Separately, the Tau NexGen study in Dominantly Inherited Alzheimer's disease, led by Washington University School of Medicine in St. Louis, has included lecanemab as the backbone anti-amyloid therapy since January 2022.