NUTLEY, N.J., April 9, 2026 /PRNewswire/ -- Eisai Inc. announced today the company will present the latest findings on lecanemab (generic name, brand name: LEQEMBI^®), Eisai's anti-amyloid beta (Aβ) protofibril antibody for the treatment of Alzheimer's disease (AD), at the 2026 American Academy of Neurology (AAN) Annual Meeting from April 18-22 in Chicago and online. The lecanemab data and additional research findings from Eisai's neurology portfolio will be featured in 14 presentations, including four oral presentations. Eisai will also host an Industry Therapeutic Update.

Oral and Poster Presentations
Oral presentations during the "New Perspectives on Alzheimer's Therapeutics" scientific platform session highlight the breadth of lecanemab research, including mechanistic and biomarker insights, advances in treatment delivery, and long-term clinical outcomes. Poster presentations further underscore how lecanemab research and real-world evidence, particularly from geriatric practice settings, are shaping evolving care pathways and supporting a more standardized framework for diagnosing and treating early AD.

Eisai Industry Therapeutic Update – Smoldering Alzheimer's Disease: The Ongoing Benefit of Addressing Multiple Pathologies  
Eisai is sponsoring a two-part symposium on Monday, April 20 from 6:00-8:00 PM CDT featuring five leading global experts in the field of AD. The first session will focus on the newly emerging concept of smoldering AD, a slow-burning process that begins decades before clinical symptoms. The second session will explore how anti-amyloid therapy addresses multiple aspects of AD, including and extending beyond plaque removal.

The symposium aims to equip healthcare professionals with practical, evidence-based insights to support earlier detection of AD, confident interpretation of biomarkers across the disease continuum, and stronger patient and care partner conversations. The program draws on clinical trial data, long-term outcomes, and real-world evidence to translate emerging science into clinical practice.

AAN 2026 Presentations Relating to Eisai's Key Compounds and Research

Oral Presentations

Poster Presentations

Lecanemab

Diagnosis & Treatment in Early Alzheimer's Disease

Lemborexant

E2086

Eisai serves as the lead of lecanemab development and regulatory submissions globally with both Eisai and Biogen 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 successfully complete clinical development or gain health authority approval.

MEDIA CONTACTS

Public Relations Department,
Eisai Co., Ltd.
+81-(0)3-3817-5120

Eisai Europe, Ltd.
(Europe, Australia, New Zealand and Russia)
EMEA Communications Department
+44 (0) 7739-600-678
EMEA-comms@eisai.net

Eisai, Inc. (U.S.)
Julie Edelman
+1-862-213-5915
Julie Edelman@eisai.com

[Notes to editors]
1. About lecanemab (generic name, brand name: LEQEMBI^®)
Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. It is a humanized immunoglobulin gamma (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ).

Lecanemab has been approved in 53 countries and regions including Japan, the United States, China, Europe, South Korea, Taiwan, and Saudi Arabia, and is under regulatory review in 6 countries. Following the initial phase with treatment every two weeks for 18 months, intravenous (IV) maintenance dosing with treatment every four weeks was approved in 7 countries including the U.S., China, the UK, and others, and applications have been filed in 10 countries and regions. The U.S. FDA approved Eisai's Biologics License Application (BLA) for subcutaneous maintenance dosing with LEQEMBI IQLIK in August 2025. A Supplemental Biologics License Application (sBLA) for initiation treatment was accepted in January 2026. The sBLA has been granted Priority Review, with a Prescription Drug User Fee Act (PDUFA) action date of May 24, 2026. In November 2025, an application for a subcutaneous injectable formulation in Japan was submitted. In January 2026, the Biologics License Application (BLA) for the subcutaneous formulation was accepted in China. In December 2025, Lecanemab (IV) has been included in the "Commercial Insurance Innovative Drug List", recently introduced by the National Healthcare Security Administration (NHSA) of China.

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 that provides the infrastructure for academic clinical trials in AD and related dementias in the U.S, funded by the National 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 of Medicine in St. Louis, is ongoing and includes lecanemab as the backbone anti-amyloid therapy.

2. About Protofibrils
Protofibrils are believed to contribute to the brain injury that occurs with AD and are considered to be the most toxic form of soluble Aβ, having a primary role in the cognitive decline associated with this progressive, debilitating condition.¹ Protofibrils cause injury to neurons in the brain, which in turn, can negatively impact cognitive function via multiple mechanisms, not only increasing the development of insoluble Aβ plaques but also increasing direct damage to brain cell membranes and the connections that transmit signals between nerve cells or nerve cells and other cells. It is believed the reduction of protofibrils may prevent the progression of AD by reducing damage to neurons in the brain and cognitive dysfunction.²

3. About lemborexant (product name: DAYVIGO^®)
Lemborexant, an orexin receptor antagonist, is Eisai's in-house discovered and developed small molecule that inhibits orexin neurotransmission by binding competitively to the two subtypes of orexin receptors (orexin receptor 1 and 2). Fast on/off receptor kinetics of lemborexant to orexin receptors may influence lemborexant's potential to facilitate improvements in sleep onset and maintenance with minimal morning residual effects. It has been approved for the treatment of insomnia in more than 25 countries including Japan, the United States, China, Canada, Australia and countries in Asia and the Middle East.

4. About E2086
E2086 is Eisai's in-house discovered novel selective orexin 2 receptor agonist. Nonclinical studies have demonstrated statistically significant increases in time spent awake and significant reductions in rates of cataplexy. Furthermore, in a Phase Ib clinical trial with patients with narcolepsy type 1, the agent demonstrated a statistically significant reduction in excessive daytime sleepiness compared to placebo or the existing drug (modafinil).³ In February 2026, it was designated as an orphan drug for narcolepsy by the Ministry of Health, Labour and Welfare in Japan.

5. About the Collaboration between Eisai and Biogen for AD
Eisai and Biogen have been collaborating on the joint development and commercialization of AD treatments since 2014. Eisai serves as the lead of LEQEMBI development and regulatory submissions globally with both companies co-commercializing and co-promoting the product and Eisai having final decision-making authority.

6. About the Collaboration between Eisai and BioArctic for AD
Since 2005, Eisai and BioArctic have had a long-term collaboration regarding the development and commercialization of AD treatments. Eisai obtained the global rights to study, develop, manufacture and market lecanemab for the treatment of AD pursuant to an agreement with BioArctic in December 2007. The development and commercialization agreement on the antibody lecanemab back-up was signed in May 2015.

References

1. Amin L, Harris DA. Aβ receptors specifically recognize molecular features displayed by fibril ends and neurotoxic oligomers. Nat Commun. 2021;12: 3451. doi:10.1038/s41467-021-23507-z.
2. Ono K, Tsuji M. Protofibrils of Amyloid-β are Important Targets of a Disease-Modifying Approach for Alzheimer's Disease. Int J Mol Sci. 2020;21(3):952. doi: 10.3390/ijms21030952. PMID: 32023927; PMCID: PMC7037706.
3. Eisai Co., Ltd. E2086, A Selective Orexin Receptor-2 Agonist, Promotes Wakefulness in Patients with Narcolepsy Type-1. Presented at the World Sleep Congress, Singapore, 8 September 2025.

SOURCE Eisai Inc.