EISAI PRESENTS NEW DATA ON THE RELATIONSHIP BETWEEN CLINICAL, BIOMARKER AND SAFETY OUTCOMES FROM THE LECANEMAB PHASE 2B STUDY FOR EARLY ALZHEIMER’S DISEASE IN LATE-BREAKERS AND PIPELINE UPDATES AT THE 14TH CLINICAL TRIALS ON ALZHEIMER’S DISEASE (CTAD) CONFERENCE

Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) announced today the presentation of data from the company’s extensive Alzheimer’s disease (AD) pipeline, including six oral presentations that will provide deeper insights into lecanemab’s potential as a treatment for early AD. Eisai initiated a rolling submission of a Biologics License Application (BLA) for lecanemab, an investigational anti-amyloid beta (Aβ) protofibril antibody, for the treatment of early AD, to the U.S. Food and Drug Administration (FDA) under the accelerated approval pathway in September 2021. The lecanemab data and additional research findings from Eisai’s robust AD pipeline will be featured in 10 presentations, including five late breaker oral presentations, at the 14th Clinical Trials on Alzheimer’s Disease (CTAD) conference, November 9-12, 2021, in Boston, Massachusetts and virtually.

“The findings Eisai will present at CTAD provide scientific insights into the potential role of lecanemab in the treatment of early Alzheimer’s disease as well as the relationship between clearance of amyloid-beta plaque from the brain, changes in blood-based biomarkers and clinical outcomes,” said?Michael Irizarry, M.D., Vice President, Deputy Chief Clinical Officer, Neurology Business Group, Eisai Inc. “We are working to advance lecanemab and our other targeted investigational compounds as quickly as possible in our commitment to bringing solutions to patients and their families.”

The focus on AD has historically been on alleviating cognitive, functional, and behavioral symptoms, but there has been significant progress in understanding the biological mechanisms of the disease and Eisai’s investigational pipeline aims to treat the range of underlying pathophysiology, including amyloid, tau and neurodegeneration.

“With lecanemab’s rolling BLA submission to the FDA under the accelerated approval pathway, completion of enrollment of 1,795 patients in the confirmatory Phase 3 Clarity AD clinical trial, initiation of a lecanemab subcutaneous dosing Phase 1 study and the ongoing Phase 3 AHEAD 3-45 study in people with pre-clinical Alzheimer’s disease, it is an exciting time for lecanemab and Eisai’s AD franchise,” said Ivan Cheung, Chairman, Eisai Inc., Senior Vice President, President Neurology Business Group and Global Alzheimer’s Disease Officer, Eisai Co., Ltd. “We are optimistic about the promise lecanemab and other investigational compounds in our robust pipeline may have for people living with Alzheimer’s disease.”

Major Presentations Provide Deeper Scientific Insights into Lecanemab’s Potential as a Treatment for Early AD

· Roundtable: Presentation of the latest lecanemab data, followed by esteemed faculty, Drs. Jeffrey Cummings, Randall Bateman and Christopher van Dyck, facilitating a conversation about the results and insights useful to the broader AD community (Oral Roundtable 5)

· Oral presentation about consistency of efficacy assessments across various statistical methods from the lecanemab Phase II proof-of-concept study (Study 201) in people living with early AD (LB9)

· Oral presentation regarding the introduction of plasma biomarker screening for Phase 3 AHEAD 3-45 study for preclinical AD (LB4)

· Oral presentation outlining the baseline characteristics for the Phase 3 Clarity AD clinical trial for people living with early AD (ROC22)