No.23-51

July 12, 2023
Eisai Co., Ltd.

EISAI TO PRESENT THE LATEST ALZHEIMER’S DISEASE PIPELINE AND
RESEARCH, INCLUDING LECANEMAB AND ANTI-MTBR TAU ANTIBODY E2814, AT
THE ALZHEIMER’S ASSOCIATION INTERNATIONAL CONFERENCE (AAIC) 2023

Eisai Co. Ltd (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) announced today that the company will
present the latest findings on its Alzheimer’s disease (AD) pipeline and research, including Eisai’s antiamyloid beta (Aβ) protofibril* antibody for the treatment of Alzheimer’s disease (AD), lecanemab (genericname, U.S. brand name: LEQEMBI®), and the company’s investigational anti-MTBR** tau antibody, E2814,
at the Alzheimer’s Association International Conference (AAIC). The conference will be held in Amsterdam,
the Netherlands and virtually from July 16 to 20, 2023. Eisai will present data and research in eight oral and19 poster presentations at the meeting. Two of the AAIC oral presentations will be presented as posters at
the Alzheimer’s Disease Imaging Consortium (AIC), which will be held at the same venue as AAIC on July
15.
“At AAIC 2023 Eisai will present the latest data on lecanemab, an anti-Aβ protofibril antibody, that recentlyreceived traditional approval in the U.S. for patients with mild cognitive impairment (MCI) due to AD and mildAD. Leqembi was studied in a broad population, which included a mix of racial and ethnic groups and patientswith common comorbid conditions and concomitant medications.” Additionally, Eisai will present importantnew data on E2814, an anti-MTBR tau antibody, which is currently in Phase II/III clinical trials with theDominantly Inherited Alzheimer’s Network Trials Unit at Washington University St. Louis,” said Michael
Irizarry, M.D., Deputy Chief Clinical Officer and Senior Vice President of Clinical Research, Alzheimer’s
Disease and Brain Health, Eisai Inc. “As part of Eisai’s commitment to transparency and our human healthcare (hhc) and ecosystem mission, we will continue to present and publish data and information about ourAD pipeline and research.”
Key Eisai AAIC Presentations•Amyloid Reduction and Evidence of Downstream Biomarker Modification Presentation of resultsof Aβ, tau, neurodegeneration, gliosis, and imaging biomarkers in the Phase III Clarity AD study oflecanemab (#80907)•Drug Development in the Era of Anti-Amyloid Therapies Discussion of considerations in thedevelopment of new drugs for AD and rational drug combinations based on pathophysiology (#70444)•Subcutaneous Lecanemab is Predicted to Achieve Comparable Efficacy and Improved Safety
Compared to Lecanemab IV in Early Alzheimer's Disease Presentation and discussion of resultsfrom studies to date on a subcutaneous formulation of lecanemab under development to potentially
improve convenience and safety profile for patients (#82852)•E2814: An Anti-Tau Therapy Engages its CNS Target and Affects the Downstream Tangle-SpecificBiomarker MTBR-tau243 in Dominantly Inherited Alzheimer's Disease Report on the safety,
pharmacokinetics, and biomarkers of anti-MTBR tau antibody E2814 in clinical trials in healthy adults
and dominant inherited AD patients (#82771)

■ Eisai Oral Presentations
Asset/Project, Session,
Presentation Time (Central

Presentation Number, Title

European Summer Time)
Lecanemab
Plenary Panel
Wednesday, July 19, 2023
Session Time: 11:15 - 12:30#80907
Amyloid Reduction and Evidence of Downstream Biomarker Modification

AAIC ASK Session (Q&A): 13:00
Lecanemab
Perspectives Session#70444

Monday, July 17, 2023

Drug Development in the Era of Anti-Amyloid Therapies

Session Time: 14:15 - 15:30
Lecanemab#82852

Monday, July 17, 2023

Subcutaneous Lecanemab is Predicted to Achieve Comparable Efficacy andSession Time: 8:00 - 8:45

Improved Safety Compared to Lecanemab IV in Early Alzheimer's Disease

Lecanemab#83020

Monday, July 17, 2023

Racial and Ethnic Differences in Plasma Biomarker Eligibility in a PreclinicalSession Time: 8:00 - 8:45

Alzheimer's Disease Trial#80393

Lecanemab

Exposure-Response Modeling to Describe Change in Brain Amyloid

Thursday, July 20, 2023
Session Time: 8:00 - 9:15

Disease#82771

E2814

E2814: An Anti-Tau Therapy Engages its CNS Target and Affects theSunday, July 16, 2023
Session Time: 8:00 - 8:45
Biomarkers
Session Time: 14:15 - 15:30
Imaging

Downstream Tangle-Specific Biomarker MTBR-tau243 in Dominantly
Inherited Alzheimer's Disease#80421

Sunday, July 16, 2023
Alzheimer's

Following Lecanemab Administration in Patients with Early Alzheimer'sConsortium(AIC), Poster AIC-P-243

Harmonization of Tau PET in Alzheimer’s Disease: Comparison of Methods
to Derive CenTauR Units for [18F]RO948, [18F]Flortaucipir and [18F]MK6240

Biomarkers
Monday, July 17, 2023

#75367

Session Time: 16:15 - 17:30

Novel CSF Tau Biomarkers Can Be Used For Disease Staging of Sporadic

Alzheimer's

Alzheimer’s Disease

Imaging

Consortium(AIC), Poster AIC-P-061(continued on the following page)■ Eisai Poster Presentations
Asset/Project, Session,
Presentation Time (Central

Poster Number, Title

European Summer Time)
Lecanemab

Poster P1-746

Sunday, July 16, 2023

PK/PD Analysis of ARIA-E and Isolated ARIA-H in Lecanemab Clarity AD

Poster Session Time: 8:45 - 16:15

StudyE2814

Poster P1-909

Sunday, July 16, 2023

Safety, Pharmacokinetics and Immunogenicity of Single and Multiple

Poster Session Time: 8:45 - 16:15

Ascending Doses of the Anti-Tau Therapeutic Antibody E2814: A Phase 1,
First-in-Human Study in Healthy Subjects

E2814

Poster P4-673

Wednesday, July 19, 2023

Efficacy of the Murine Version of E2814 in a Validated AD Brain Seed-

Poster Session Time: 8:45 - 16:15

Injection Model in hTau Mice

Biomarkers

Poster P1-504

Sunday, July 16, 2023

Detection of Brain Tau Deposition Across Braak Stages Using Plasma

Poster Session Time: 8:45 - 16:15

pTau181, MRI and Cognitive Function Assessments

Biomarkers

Poster P2-288

Monday, July 17, 2023

Deciphering the Components of Amyloid-Beta-Driven Dementia Using a

Poster Session Time: 8:45 - 16:15

Novel Peptide-Focused Global Proteomics Platform

Biomarkers
Monday, July 17, 2023
Poster Session Time: 8:45 - 16:15
Biomarkers
Monday, July 17, 2023
Poster Session Time: 8:45 - 16:15

Poster P2-911
Discordance in Amyloid Positivity Defined by Visual Reads and Centiloids
Poster P2-955
Estimating Braak Stage From [18F]MK6240 PET Scans

Biomarkers

Poster P3-257

Tuesday, July 18, 2023

A New De Novo-Assisted Mass Spectrometry Method for Novel Antimicrobial

Poster Session Time: 8:45 - 16:15

Peptide Expression Profiling in Cerebrospinal Fluid of Demented Subjects

Biomarkers

Poster P3-281

Tuesday, July 18, 2023

Targeted Proteomic Profiling in Cerebrospinal Fluid and Plasma Identifies

Poster Session Time: 8:45 - 16:15

Biomarkers for Alzheimer’s Disease

Machine-Learning Models

Poster P4-655

Wednesday, July 19, 2023

Prognostic Prediction of the Longitudinal Cognitive Trajectory of Amyloid-

Poster Session Time: 8:45 - 16:15

Positive Patients with Mild Dementia

Drug Development

Poster P4-642

Wednesday, July 19, 2023

Development of Clinical Trial Simulation Tools for Alzheimer’s Disease

Poster Session Time: 8:45 - 16:15

through the Critical Path for Alzheimer’s Disease Consortium(continued on the following page)Public Health

Poster P2-790

Monday, July 17, 2023

Development of a Triage Algorithm for Mild Cognitive Impairment Using

Poster Session Time: 8:45 - 16:15

Electronic Health Record Data

Epidemiology

Poster P1-771

Sunday, July 16, 2023Age-Related Relative Comorbidity Burden of Mild Cognitive Impairment: A

Poster Session Time: 8:45 - 16:15

US Database Study

Epidemiology

Poster P1-775

Sunday, July 16, 2023

Prevalence and Severity Distribution of Alzheimer’s Disease in the United

Poster Session Time: 8:45 - 16:15

States from the Health and Retirement Study

Epidemiology

Poster P2-760

July 17, 2023

Incidence of Alzheimer’s Disease Dementia and Mild Cognitive Impairment

Poster Session Time: 8:45 - 16:15

in the United States Medicare Population

Epidemiology

Poster P4-721

July 17, 2023

Prevalence of Alzheimer’s Disease Dementia and Mild Cognitive Impairment

Poster Session Time: 8:45 - 16:15

in the United States Medicare Population

Health Services Research
Poster Virtual Only
Sunday, July 16 - Thursday, July 20,
2023
Health Services Research
Poster Virtual Only
Sunday, July 16 - Thursday, July 20,
2023
OthersPoster Virtual Only
Sunday, July 16 - Thursday, July 20,
2023

Abstract 70962
Retrospective Cohort Study to Quantify the Economic Impact of Mild
Cognitive Impairment
Abstract 72143
Economic Impact of Progression from Mild Cognitive Impairment toAlzheimer’s Disease in Commercially Insured SubjectsAbstract 73976
Association between Auditory Impairment and the Onset of Alzheimer's
Disease: The LIFE Study

Eisai serves as the lead of lecanemab development and regulatory submissions globally with both companies
co-commercializing and co-promoting the product and Eisai having final decision-making authority.
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 successfullycomplete clinical development or gain health authority approval.
*Protofibrils are large Aβ aggregated soluble species of 75-5000 Kd.1,2,3** MTBR: microtubule binding region
References
1. https://www.alzforum.org/news/conference-coverage/lecanemab-sweeps-toxic-av-protofibrils-catches-eyes-trialists
2. Sehlin D, Englund H, Simu B, Karlsson M, Ingelsson M, Nikolajeff F, Lannfelt L, Pettersson FE. Large aggregates are

the major soluble Aβ species in AD brain fractionated with density gradient ultracentrifugation. PLoS
One. 2012;7(2):e32014. doi: 10.1371/journal.pone.0032014. Epub 2012 Feb 15. PMID: 22355408; PMCID:
PMC3280222.
3.
Söderberg, L., Johannesson, M., Nygren, P. et al. Lecanemab, Aducanumab, and Gantenerumab — Binding Profiles
to Different Forms of Amyloid-Beta Might Explain Efficacy and Side Effects in Clinical Trials for Alzheimer’s
Disease. Neurotherapeutics. 2023;20:195-206. doi: 10.1007/s13311-022-01308-6.

MEDIA CONTACTS:
Eisai Co., Ltd.
Public Relations Department
TEL: +81 (0)3-3817-5120
Eisai Inc. (U.S.)
Libby Holman+ 1-201-753-1945
Libby_Holman@Eisai.com
Eisai Europe, Ltd.
(UK, Europe, Australia, New Zealand and Russia)
EMEA Communications Department+44 (0) 786 601 1272
EMEA-comms@eisai.net[Notes to editors]
1. About Lecanemab (generic name, U.S. brand name: LEQEMBI®),
Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. Lecanemab is ahumanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble(protofibril) and insoluble forms of amyloid-beta (Aβ). In the U.S., LEQEMBI was granted traditional approvalby the U.S. Food and Drug Administration (FDA) on July 6, 2023. Treatment with LEQEMBI should be initiatedin patients with mild cognitive impairment or mild dementia stage of disease, the population in which
treatment was initiated in clinical trials. There are no safety or effectiveness data on initiating treatment atearlier or later stages of the disease than were studied.
Please see full Prescribing Information, including Boxed WARNING in the United States.
Eisai has also submitted applications for approval of lecanemab in Japan, EU, China, Canada, Great Britain
and South Korea. In Japan and China, the applications have been designated for priority review, and in GreatBritain, lecanemab has been designated for the Innovative Licensing and Access Pathway (ILAP), whichaims to reduce the time to market for innovative medicines.
Eisai has completed lecanemab subcutaneous bioavailability study, and subcutaneous dosing is currently
being evaluated in the Clarity AD (Study 301) OLE. A maintenance dosing regimen has been evaluated aspart of Study 201 as well as the Clarity AD (Study 301) OLE. Separate supplemental Biologics License
Applications for subcutaneous dosing and a maintenance dosing regimen will be submitted to the FDA at theend of Eisai's fiscal year.
Since July 2020 the Phase 3 clinical study (AHEAD 3-45) for individuals with preclinical AD, meaning they
are clinically normal and have intermediate or elevated levels of amyloid in their brains, is ongoing. AHEAD
3-45 is conducted as a public-private partnership between the Alzheimer’s Clinical Trial Consortium thatprovides the infrastructure for academic clinical trials in AD and related dementias in the U.S, funded by theNational Institute on Aging, part of the National Institutes of Health, Eisai and Biogen.

Since January 2022, the Tau NexGen clinical study for Dominantly Inherited AD (DIAD), that is conducted by
Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU), led by Washington University School ofMedicine in St. Louis, is ongoing.
2. About E2814
An investigational anti-microtubule binding region (MTBR) tau antibody, E2814, is being developed as adisease-modifying agent for tauopathies including sporadic AD. Phase I clinical studies are underway. E2814
was discovered as part of the research collaboration between Eisai and University College London. E2814
is designed to prevent the spreading of tau seeds within the brains of affected individuals. In addition, aPhase II/III Tau NexGen study for the treatment of dominantly inherited Alzheimer's disease (DIAD),conducted by the Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU) led by Washington
University School of Medicine in St. Louis (St. Louis, MO, USA), is underway.
3. About the Collaboration between Eisai and Biogen for Alzheimer’s Disease
Eisai and Biogen have been collaborating on the joint development and commercialization of AD treatments
since 2014. Eisai serves as the lead of lecanemab development and regulatory submissions globally withboth companies co-commercializing and co-promoting the product and Eisai having final decision-makingauthority.
4. About the Collaboration between Eisai and BioArctic for Alzheimer’s Disease
Since 2005, Eisai and BioArctic have had a long-term collaboration regarding the development andcommercialization of AD treatments. Eisai obtained the global rights to study, develop, manufacture andmarket lecanemab for the treatment of AD pursuant to an agreement concluded with BioArctic in December
2007 The development and commercialization agreement on the antibody lecanemab back-up was signed
in May 2015.