Eisai Co. Ltd (Headquarters: Toyoko, CEO: Haruo Naito, ¡°Eisai¡±) announced today that the company will present research from its Alzheimer¡¯s disease (AD) pipeline, including new data for lecanemab (BAN2401), an investigational anti-amyloid beta (A¦Â) protofibril antibody for the treatment of mild cognitive impairment (MCI) due to Alzheimer¡¯s disease (AD) and mild AD (collectively known as early AD) with confirmed presence of amyloid pathology in the brain, at the Alzheimer¡¯s Association International Conference (AAIC) to be held in San Diego, CA and virtually from July 31 to August 4, 2022. Eisai will present data and research in three oral and 18 poster presentations at the meeting.

On July 5, 2022 (U.S), Eisai announced that the U.S. Food and Drug Administration (FDA) accepted the Biologics License Application (BLA) for lecanemab under the accelerated approval pathway and was granted priority review, with a Prescription Drug User Fee Act (PDUFA) action date of January 6, 2023. The readout of the primary endpoint data of Clarity AD will occur in the Fall of 2022. The FDA has agreed that the results of Clarity AD when completed, can serve as the confirmatory study to verify the clinical benefit of lecanemab.

Key Eisai AAIC Presentations

¡¤ Effect of Genotype on ARIA-E Incidence by Lecanemab: Results from a modeling simulation to evaluate the effect of APOE4 genotype on ARIA-E incidence from study 201 Core and comparison to the observed incidence in the open-label extension among those newly treated with lecanemab. (Virtual Developing Topics #69402)

¡¤ Lecanemab Subcutaneous Dosing:

* Results from a study in healthy subjects to evaluate the absolute bioavailability, pharmacokinetics, safety, and immunogenicity of lecanemab following a single fixed 700 mg subcutaneous dose. (Poster/Abstract #69438)

* Modeling and simulation analysis aimed at showing the equivalence of fixed weekly subcutaneous dose of lecanemab to body weight-based 10mg/kg biweekly intravenous dose. (Poster/Abstract #69429)

¡¤ Ethnic and Racial Diversity in Eisai Clinical Trials: An evaluation of US enrollment across lecanemab (Study 201 and Clarity AD) and elenbecestat MissionAD studies in early AD to assess racial and ethnic groups and the impact of eligibility criteria in the United States. (Poster/Abstract ?# 69198)

¡¤ ¦Â-Amyloid Assays Predict Brain ¦Â-Amyloid Pathology: Data from the Eisai and Sysmex collaboration reporting on the fully automated plasma A¦Â40 and A¦Â42 immunoassays and their performance for predicting brain A¦Â pathology defined by amyloid PET. (Poster/Abstract # 68727)

¡¤ Comprehensive CSF Tau Profiling from Dominantly Inherited Alzheimer Network (DIAN): An oral presentation that shares results from a study in patients enrolled in Washington University School of Medicine¡¯s DIAN-observational cohort that used Eisai¡¯s anti-microtubule binding region (MTBR) antibody, E2814, to profile MTBR-tau and then assessed timing to MTBR-tau changes in CSF and correlation to clinical, cognitive, and biomarker changes. (Oral Presentation # 65313)

¡°The lecanemab data Eisai will present at AAIC 2022 continues to build the body of knowledge about our investigational anti-amyloid beta protofibril antibody as we work toward the Phase 3 confirmatory Clarity AD readout this fall,¡± said Michael Irizarry, M.D., Senior Vice President, Deputy Chief Clinical Officer, Alzheimer¡¯s Disease and Brain Health, Eisai Inc. ¡°Additional research presented will highlight Eisai¡¯s efforts to improve ethnic and racial diversity in our early Alzheimer¡¯s disease clinical trials in the United States so that study populations mirror the U.S. Medicare population, as well as research from our collaboration with Sysmex on potential biomarkers that may contribute to early diagnosis of Alzheimer’s disease.¡±

AAIC 2022 Presentations Relating to Eisai’s Key Compounds and Research

?¡ö Eisai Oral Presentations

This release discusses investigational uses of agents in development and is not intended to convey conclusions about efficacy or safety. There is no guarantee that such investigational agents will successfully complete clinical development or gain health authority approval.

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Eisai Inc. (U.S.)

Libby Holman

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