At AD/PD, Dr Johanna Fälting, Head of R&D at BioArctic, held an oral presentation on exidavnemab, the company's proprietary drug candidate aimed at treating Parkinson's disease and other alpha-synucleinopathies. The binding profile of exidavnemab was presented, demonstrating a high affinity and selectivity for pathological aggregated forms of alpha-synuclein and a low affinity for physiological monomers. In the Phase 1 studies, exidavnemab was generally well tolerated and demonstrated an elimination half-life of approximately 30 days. These properties make exidavnemab a suitable candidate for future studies of disease modification in alpha-synucleinopathies. The design of the ongoing EXIST Phase 2a study in Parkinson's disease was presented. The presentation can be found on BioArctic's website.

New data on lecanemab were also presented at the conference. Lecanemab is an anti-amyloid beta (Aβ) monoclonal antibody that preferentially binds to toxic protofibrils (soluble Aβ aggregates), in addition to targeting and reducing Aβ plaques (insoluble Aβ aggregates). Dr Linda Söderberg from BioArctic presented a poster on lecanemab's binding profile that confirmed the high selectivity for the toxic Aβ protofibrils in Alzheimer's disease brains. The limited binding to fibril structures in CAA (cerebral amyloid angiopathy) may explain the ARIA-E frequency reported for lecanemab.

In addition to BioArctic's presentations, Eisai also held several presentations on lecanemab.

In an oral presentation by Dr Michael Rosenbloom, University of Washington, USA, recent findings from real-world clinical evidence of lecanemab in the United States were presented. The utilization patterns showed that real-world use of lecanemab conforms with the FDA approved prescribing recommendations, and patient adherence suggests that neither MRI monitoring nor possible adverse events significantly interfered with lecanemab dosing.

In two other presentations, Dr Lutz Froelich, University of Heidelberg, Germany, presented the efficacy and safety outcomes of lecanemab in early AD apolipoprotein E ε4 (ApoEε4) heterozygous carriers and non-carriers in the Phase 3 Clarity AD clinical study. The data presented were forming the basis for the regulatory approval in United Kingdom and the positive CHMP recommendation for EU approval, respectively. The data for the UK and EMA proposed indicated population confirmed that the effects of lecanemab were similar to the overall Clarity AD population with lower risk of ARIA events.

"It is inspiring to see all the data presented at the conference and reassuring that the real-world data reported for lecanemab conforms with the Phase 3 results. It is also great to see how the field is moving forward, with encouraging data regarding alpha-synuclein, blood brain barrier transportation approaches as well as biofluid biomarkers and blood-based diagnostics", said Gunilla Osswald, CEO at BioArctic."

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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 person below, on April 7, 2025, at 12:00 CET.  

For further information, please contact:

Charlotte af Klercker, Senior Director Sustainability and Communications
Telephone: +46 73 515 09 70
E-mail: charlotte.afklercker@bioarctic.com

Anders Martin-Löf, CFO 
Phone: +46 70 683 79 77 
E-mail: anders.martin-lof@bioarctic.com

About exidavnemab
Exidavnemab is a monoclonal antibody drug candidate that is designed to selectively bind and eliminate aggregated forms of alpha-synuclein such as oligomers and protofibrils and fibrillar forms, which participates in neurodegenerative disorders including Parkinson's disease and Multiple System Atrophy (MSA). The goal is to develop a disease modifying treatment that stops or slow down the progression of alpha-synucleinopathies e.g. Parkinson's disease and MSA. BioArctic's phase 2a study EXIST with exidavnemab in Parkinson's disease is ongoing since 2024. EXIST is an important step towards a proof-of-concept study focusing on the efficacy of the drug candidate.

In March 2025, the US FDA Office of Orphan Products Development (OOPD) granted orphan drug designation (ODD) to exidavnemab for the treatment of MSA.

About lecanemab

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 amyloidbeta (Aβ).

Lecanemab is approved in the U.S., Japan, China, the United Kingdom and several other countries. Eisai has submitted applications for approval of lecanemab several other countries and regions including EU. 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. In January 2025, the supplemental Biologics License Application (sBLA) for intravenous (IV) maintenance dosing of the treatment was approved in the U.S. After an 18 months initiation phase with once every two weeks of dosing, a transition to the maintenance dosing regimen of 10 mg/kg once every four weeks or continuing 10 mg/kg once every two weeks may be considered. Additionally, the U.S. Food and Drug Administration (FDA) accepted Eisai's Supplemental Biologics License (BLA) for the LEQEMBI subcutaneous autoinjector for weekly maintenance dosing in January 2025 and set a PDUFA action date for August 31, 2025.

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.

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 the right to commercialize lecanemab in the Nordic region 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 innovative treatments that can delay or stop the progression of neurodegenerative diseases. The company is the originator of Leqembi® (lecanemab) - the world's first drug proven to slow the progression of the disease and reduce cognitive impairment in early Alzheimer's disease. Leqembi has been developed together with Eisai. BioArctic has a broad research portfolio within Alzheimer's disease, Parkinson's disease, ALS and enzyme deficiency diseases. Several of the projects utilize the company's proprietary BrainTransporter™ technology, which improves the transport of drugs into the brain. BioArctic's B share (BIOA B) is listed on Nasdaq Stockholm Large Cap. For more information, please visit www.bioarctic.com.