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New data from LEQEMBI® (lecanemab-irmb) phase 3 Clarity AD study and subcutaneous formulation to be presented at CTAD

Non Regulatory

Stockholm, October 16, 2023 – BioArctic AB’s (publ) (Nasdaq Stockholm: BIOA B) partner Eisai will present new data from the phase 3 Clarity AD study for its Alzheimer’s disease (AD) treatment LEQEMBI® (lecanemab-irmb) 100 mg/mL injection for intravenous use, as well as new data on the subcutaneous formulation in development at the 16th annual Clinical Trials on Alzheimer’s Disease (CTAD) conference. The conference will be held in Boston, Massachusetts, United States and virtually from October 24 to 27, 2023. In addition, BioArctic will give an oral presentation on binding profiles of lecanemab and donanemab to different amyloid-beta species.

The full list of presentations related to lecanemab can be found below.

Late-Breaking Symposium 4 – Lecanemab for early Alzheimer’s Disease: Long-Term Outcomes, Predictive Biomarkers, and Novel Subcutaneous Administration

  • In a late-breaking symposium on October 25 from 17:25-18:05 EDT, Eisai will present the latest data from the Clarity AD optional tau PET longitudinal substudy. The presentation will include a post-hoc analysis of the low and intermediate + high-tau subgroups, with the low-tau subgroup representing an early disease stage studied in the phase 3 core study and open-label extension study. An update on data with the investigational subcutaneous formulation of lecanemab, including interim safety and effect on amyloid in the brain measured by amyloid PET, will also be provided.
  • Distinguished faculty members Christopher van Dyck M.D., Keith Johnson M.D. and Reisa Sperling M.D. will discuss the findings in a panel led by Michael Irizarry, M.D., MPH, Eisai.
  • A live webcast of this symposium can be viewed on the Eisai Co., Ltd. website.
Presentation Title
Clarity AD: Review of the Mechanism-Based Rationale and Results of the Lecanemab Phase 3 Trial
Biomarker Assessments from Clarity AD: A Focus on Downstream Implications of Targeting Protofibrils[i] and Tau as a Predictive Biomarker
Lecanemab for the Treatment of Early Alzheimer’s Disease: The Extension of Efficacy Results from Clarity AD
Preliminary Update on Lecanemab Safety in Clarity AD Open-Label Extension, Including Subcutaneous Formulation
Panel discussion, Q&A

Oral Presentations

Asset/Project, Presentation Time (EDT) Presentation Number, Title
Lecanemab October 26 (Thu) 14:50-15:05 OC19Binding Profiles of Lecanemab and Donanemab to Different Amyloid-beta Species(presentation by BioArctic)
Lecanemab October 26 (Thu) 17:05-17:45(Late breaking symposium 6) Presentation 3 in Late breaking symposium 6Aβ42/Aβ40 and Phospho-tau217 Concentration Ratios Increase the Accuracy of Amyloid PET Classification in Preclinical Alzheimer's Disease

Poster Presentations

Asset/Project Presentation Number, Title
Lecanemab P018Recruitment Source, Eligibility and Reason for Prescreen-Fail Across Sex, Race and Ethnicity: Preliminary Analysis of Prescreening Data from the AHEAD Study
Lecanemab P045ARIA by Clinical Subgroup and Baseline Amyloid PET Centiloid Levels from the Lecanemab Clarity AD
Lecanemab LP011Impact of a Site Supplemental Funding Program to Alleviate Recruitment Burden: Experiences in the Preclinical Alzheimer’s Disease AHEAD Study

This release discusses investigational uses of an agent 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.

The information was released for public disclosure, through the agency of the contact persons below, on October 16, 2023, at 08.00 a.m. CET.

For further information, please contact: 
Oskar Bosson, VP Communications and IR

Phone: +46 70 410 71 80 

Jiang Millington, Director Corporate Communication and Social Media
Phone: +46 79 33 99 166

About lecanemab (generic name, U.S. brand name: LEQEMBI®)
Lecanemab is the result of a strategic research alliance between BioArctic and Eisai. Lecanemab is a humanized 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 approval by the US Food and Drug Administration (FDA) on July 6, 2023. LEQEMBI is an amyloid beta-directed antibody indicated as a disease-modifying treatment for Alzheimer’s disease (AD) in the US. Treatment with LEQEMBI should be initiated in patients with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was initiated in clinical trials. In Japan, Eisai received approval from the Ministry of Health, Labour and Welfare (MHLW) on September 25, 2023, to manufacture and market lecanemab as a treatment for slowing progression of MCI and mild dementia due to AD.

Please see full Prescribing Information, including Boxed WARNING in the United States.

Eisai has also submitted applications for approval of lecanemab in EU, China, Canada, Great Britain, Australia, Switzerland, South Korea and Israel. In China and Israel, the applications have been designated for priority review, and in Great Britain, lecanemab has been designated for the Innovative Licensing and Access Pathway (ILAP), which aims to reduce the time to market for innovative medicines.

Eisai has completed a lecanemab subcutaneous bioavailability study, and subcutaneous dosing is currently being evaluated in the Clarity AD (Study 301) open-label extension (OLE) study. A maintenance dosing regimen has been evaluated as part of the Phase 2b study (Study 201).

Since July 2020 Eisai’s 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 and Eisai.

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.

About the collaboration between BioArctic and Eisai
Since 2005, BioArctic has a long-term collaboration with Eisai regarding the development and commercialization of drugs for the treatment of Alzheimer’s disease. The most important agreements are the Development and Commercialization Agreement for the lecanemab antibody, which was signed 2007, and the Development and Commercialization agreement for the antibody LEQEMBI back-up for Alzheimer’s disease, which was signed 2015. In 2014, Eisai and Biogen entered into a joint development and commercialization agreement for lecanemab. Eisai is responsible for the clinical development, application for market approval and commercialization of the products for Alzheimer’s disease. BioArctic has right to commercialize lecanemab in the Nordic under certain conditions and is currently preparing for commercialization in the Nordics together with Eisai. BioArctic has no development costs for lecanemab in Alzheimer’s disease and is entitled to payments in connection with regulatory approvals, and sales milestones as well as royalties on global sales.

About BioArctic AB
BioArctic AB (publ) is a Swedish research-based biopharma company focusing on disease-modifying treatments for neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease and ALS. BioArctic focuses on innovative treatments in areas with high unmet medical needs. The company was founded in 2003 based on innovative research from Uppsala University, Sweden. Collaborations with universities are of great importance to the company together with its strategically important global partner Eisai in Alzheimer disease. The project portfolio is a combination of fully funded projects run in partnership with global pharmaceutical companies and innovative in-house projects with significant market and out-licensing potential. BioArctic’s Class B share is listed on Nasdaq Stockholm Large Cap (ticker: BIOA B). For more information about BioArctic, please visit

[i] One of the AD pathological features is the accumulation of clusters (plaques) of amyloid beta (Aβ) in the brain. The formation of these plaques is the result of a continuous process by which individual Aβ proteins join together, latching onto each other, one at a time, like adding links to a chain.1 In the early part of this process these small chains of Aβ are soluble and are toxic to the nerves within the brain.2,3

The most toxic of the soluble chains is called a protofibril.4 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.5

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.6


  1. Alzheimer’s Association. (2022). Brain Tour Part 2 – Alzheimer’s Effect. Retrieved September 27, 2023, from
  2. Chen, Gf., Xu, Th., Yan, Y. et al. Amyloid beta: structure, biology and structure-based therapeutic development. Acta Pharmacol. 2017;38:1205.
  3. Habashi M., Vulta S., Tripathi K., et al. Early diagnosis and treatment of Alzheimer’s disease by targeting toxic soluble Aβ oligomers. Biophysics and Computational Biology. 2022;10.1073.
  4. Hampel, H., Hardy, J., Blennow, K. et al. The Amyloid-β Pathway in Alzheimer’s Disease. Mol Psychiatry. 2021;26:5481–5503.
  5. 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
  6. 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.