EISAI TO PRESENT LECANEMAB REAL-WORLD EXPERIENCE DATA AND FINDINGS FROM NEUROLOGY PORTFOLIO AT THE AMERICAN ACADEMY OF NEUROLOGY (AAN) ANNUAL MEETING

NUTLEY, N.J., March 25, 2025 /PRNewswire/ -- Eisai Inc. announced today that the company will present the latest findings from its robust neurology portfolio, including data on real-world experience and continued maintenance dosing with our dual-acting, anti-amyloid beta (Aβ) protofibril* antibody for the treatment of Alzheimer's disease (AD), lecanemab (generic name, U.S. brand name: LEQEMBI^®) at the American Academy of Neurology (AAN) Annual Meeting, being held in San Diego, California, and virtually from April 5-9. Eisai will present two (2) oral presentations and seven (7) posters on lecanemab and the insomnia dual orexin receptor antagonist DAYVIGO^® (lemborexant) CIV.

Lecanemab Real World Experience Presentations
On Wednesday, April 9, as part of Poster Session P12, "Aging, Dementia, and Behavioral Neurology: Alzheimer's Treatment" (11:45 AM - 12:45 PM PT), two posters will be presented on real-world experience with lecanemab, including results on efficacy and safety in the clinical setting and patient satisfaction with their treatment experience:

1. Real-World Experience with Long-term Lecanemab Treatment: A Retrospective Chart Review in Early Alzheimer's Disease (Poster #012)
2. Lecanemab in Clinical Practice: Real-World Treatment Outcomes from a Retrospective Neurological Clinic Case Series Review in Early Alzheimer's Disease (Poster #008)

Oral Presentations
Oral presentations include results on lecanemab maintenance dosing, which supports the need for continued treatment of this chronic, progressive disease. Additionally, a cost-effective analysis of lecanemab in Canada will be presented.

"The data presented at AAN highlights not only the breadth and depth of real-world experience with lecanemab compared to clinical trials, but also the importance of ongoing treatment of this chronic progressive disease. Lecanemab clears highly toxic protofibrils that can continue to cause neuronal injury even after the amyloid-beta (Aβ) plaque has been cleared from the brain," said Lynn D. Kramer, M.D., FAAN, Chief Clinical Officer, Deep Human Biology Learning (DHBL), Eisai. "We are eager to engage in scientific exchange that will continue to advance neurology research and deepen our understanding of lecanemab use in clinical practice, and we remain committed to improving the lives of people who are living with early Alzheimer's disease."

• Oral Presentations

Session 23: Innovations in Dementia Treatment

• Poster Presentations

Session P1: Aging, Dementia, and Behavioral Neurology: Alzheimer's Disease Diagnostics and Biomarkers

Session P12: Aging, Dementia, and Behavior Neurology: Alzheimer's Treatment

Session P9: Sleep 3

• Industry Therapeutic Updates Sponsored by Eisai Inc.

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.

* Protofibrils are believed to contribute to the brain injury that occurs with AD and are considered to be the most toxic form of 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

[Notes to editors]

1. About lecanemab (LEQEMBI^®)
   Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. It is a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ). Lecanemab is approved in the U.S.,³ Japan,⁴ China,⁵ South Korea,⁶ Hong Kong,⁷ Israel,⁸ the United Arab Emirates,⁹ the United Kingdom,¹⁰ Mexico,¹¹ Macau and Oman.  Eisai has submitted applications for approval of lecanemab in 17 countries and regions. In the EU, in February 2025, the Committee for Medicinal Products for Human Use reaffirmed its positive opinion for lecanemab in early AD, adopted in November 2024, and the European Commission is proceeding with the decision-making process for lecanemab's marketing authorization.
   
   LEQEMBI's approvals in these countries was based on Phase 3 data from Eisai's, global Clarity AD clinical trial, in which it met its primary endpoint and all key secondary endpoints with statistically significant results. The primary endpoint was the global cognitive and functional scale, Clinical Dementia Rating Sum of Boxes (CDR-SB). In the Clarity AD clinical trial, treatment with lecanemab reduced clinical decline on CDR-SB by 27% at 18 months compared to placebo.^12,13 The mean CDR-SB score at baseline was approximately 3.2 in both groups. The adjusted least-squares mean change from baseline at 18 months was 1.21 with lecanemab and 1.66 with placebo (difference, −0.45; 95% confidence interval [CI], −0.67 to −0.23; P<0.001). In addition, the secondary endpoint from the AD Cooperative Study-Activities of Daily Living Scale for Mild Cognitive Impairment (ADCS-MCI-ADL), which measures information provided by people caring for patients with AD, noted a statistically significant benefit of 37% compared to placebo. The adjusted mean change from baseline at 18 months in the ADCS-MCI-ADL score was −3.5 in the lecanemab group and −5.5 in the placebo group (difference, 2.0; 95% CI, 1.2 to 2.8; P<0.001). The ADCS MCI-ADL assesses the ability of patients to function independently, including being able to dress, feed themselves and participate in community activities. The most common adverse events (>10%) in the lecanemab group were infusion reactions, ARIA-H (combined cerebral microhemorrhages, cerebral macrohemorrhages, and superficial siderosis), ARIA-E (edema/effusion), headache, and fall.
   
   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 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 lecanemab development and regulatory submissions globally with both companies co-commercializing and co-promoting the product and Eisai having final decision-making authority.
    
3. 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.
   
   
4. About Lemborexant (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). In individuals with normal daily sleep-wake rhythms, orexin signaling is believed to promote periods of wakefulness. In individuals with sleep-wake disorders, it is possible that orexin signaling which regulates wakefulness is not functioning normally, suggesting that inhibiting inappropriate orexin signaling may enable initiation and maintenance of sleep. It has been approved for the treatment of insomnia in over 15 countries including Japan, the United States, Canada, Australia and countries in Asia.

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. U.S. Food and Drug Administration. 2023. FDA Converts Novel Alzheimer's Disease Treatment to Traditional Approval. Last accessed: March 2025.
4. Reuters. 2023. Japan approves Alzheimer's treatment Leqembi by Eisai and Biogen. Last accessed: March 2025.
5. The Pharma Letter. 2024. Brief - Alzheimer drug Leqembi now approved in China. Last accessed: March 2025.
6. Pharmaceutical Technology. 2024. South Korea's MFDS approves Eisai-Biogen's LEQEMBI for Alzheimer's. Last accessed: March 2025.
7. Pharmaceutical Technology. 2024. Hong Kong approves Leqembi for Alzheimer's treatment. Last accessed: March 2025.
8. BioSpace. 2024. Leqembi approved for the treatment of Alzheimer's disease in Israel. Last accessed: March 2025.
9. United Arab Emirates Ministry of Health & Prevention. 2024. Registered Medical Product Directory. Leqembi. Last accessed: October 2024.
10. BioSpace. 2024. Leqembi authorized for early Alzheimer's disease in Great Britain. Last accessed: March 2025.
11. COFEPRIS authorizes innovative treatment for Alzheimer's patients. Available at: https://bit.ly/3OKks6Y. Last accessed: March 2025.
12. van Dyck, C., et al. Lecanemab in Early Alzheimer's Disease. New England Journal of Medicine. 2023;388:9-21. https://www.nejm.org/doi/full/10.1056/NEJMoa2212948.
13. Eisai presents full results of lecanemab Phase 3 confirmatory Clarity AD study for early Alzheimer's disease at Clinical Trials on Alzheimer's Disease (CTAD) conference. Available at: https://www.eisai.com/news/2022/news202285.html.

SOURCE Eisai Inc.