Biogen to Highlight New Lecanemab Data and Scientific Advances at the 18th Clinical Trials on Alzheimer's Disease Conference

• New lecanemab findings highlight the safety and potential benefits of subcutaneous administration for initiation dosing, the potential for additional long-term clinical benefits with continued treatment, and real-world experience
• Biogen is committed to deepening scientific understanding of Alzheimer's disease, including therapeutic delivery and disease progression

Biogen Inc. (Nasdaq: BIIB) today announced upcoming scientific presentations at the 18th Clinical Trials on Alzheimer's Disease (CTAD) Conference, taking place December 1-4 in San Diego. Data on LEQEMBI ® (lecanemab-irmb) will include findings on subcutaneous administration for initiation dosing, the benefits of continued therapy and estimated time savings over 10 years of treatment based on Phase 3 clinical data, and real-world experience from a post-marketing observational study in Japan and the ALZ-NET registry. The company will also share new insights into BIIB080, an investigational antisense oligonucleotide (ASO) therapy, from a healthy-volunteer biodistribution study, as well as research that helps inform understanding of disease progression.

"Following the introduction of LEQEMBI IQLIK™ in the U.S. for maintenance therapy, we look forward to sharing data that explore its potential for initiation dosing and how it may expand treatment options for patients and care partners across both phases of the treatment journey," said Priya Singhal, M.D., M.P.H., Head of Development at Biogen. "The breadth of data at CTAD also underscores the growing evidence supporting the long-term benefits of continued treatment with LEQEMBI and reflects our ongoing commitment to advancing scientific understanding of Alzheimer's disease."

Key Scientific Sessions and Presentations

Late-Breaking Symposium:

• "Lecanemab Subcutaneous Formulation for Treatment Initiation in Early Alzheimer's Disease: Optimizing Patient Care with a Potential New Option," on Wednesday, December 3 from 3:10-3:50 p.m. PT
  
  

Oral Presentations :

• "The Effects of Lecanemab Treatment on Soluble CSF Aβ Protofibrils in Clarity AD," on Tuesday, December 2 from 1:40-1:55 p.m. PT
• "Benefit Continues to Accumulate When Treatment is Continued Beyond Plaque Clearance Estimating Accumulated or Maintained Treatment Benefit in the CLARITY AD and TRAILBLAZER-ALZ2 Trials," on Tuesday, December 2 from 5:05--5:20 p.m. PT
• "Estimating the 10-Year Time-Savings Benefits of Lecanemab Treatment," on Wednesday, December 3 from 2:40-2:55 p.m. PT
• "Interim Analysis of Post-Marketing Observational Study of Lecanemab in Japan," on Thursday, December 4 from 11:40-11:55 a.m. PT

Poster Presentations:

• "Baseline Characteristics and Preliminary Safety from a Multicenter, Safety Surveillance Study of Lecanemab Treatment for Alzheimer's Disease in Real-World Clinical Practice" on Tuesday, December 2 from 7:15 a.m.-5:30 p.m. PT
• "Real-World Clinical Safety and Patient-Reported Outcomes of Treatment with Lecanemab in a New England Alzheimer's Disease Center" on Tuesday, December 2 from 7:15 a.m.-5:30 p.m. PT
• "Stability and Improvement in Early Alzheimer's Disease with Lecanemab: Sub-analysis from a United States Multicenter, Retrospective, Real-World Study" on Tuesday, December 2 from 7:15 a.m.-5:30 p.m. PT
• "Biodistribution of Radiolabeled MAPT Antisense Oligonucleotide BIIB080 Following Intrathecal Administration in Healthy Adults," on Wednesday, December 3 from 7:15 a.m.-5:30 p.m. PT
• "Baseline Study-Partner Reported but not Participant Self-Reported ECog-12 score is Associated with Subsequent Cognitive Progression on CDR-SB over 78 Weeks of Follow-up," on Thursday, December 4 from 7:15 a.m. -5:00 p.m. PT
  
  

About LEQEMBI ^® (lecanemab-irmb)
LEQEMBI (lecanemab-irmb) is the result of a strategic research alliance between Eisai and BioArctic. LEQEMBI is a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ). LEQEMBI is an amyloid beta-directed antibody for the treatment for Alzheimer's disease (AD) in the U.S. The U.S. Food and Drug Administration (FDA) granted LEQEMBI traditional approval on July 6, 2023.

LEQEMBI is indicated for the treatment of Alzheimer's disease. 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.

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.

Please see full U.S. Prescribing Information for LEQEMBI, including Boxed WARNING and Medication Guide .

About BIIB080
BIIB080 is an investigational antisense oligonucleotide (ASO) therapy designed to target microtubule-associated protein tau (MAPT) mRNA to reduce the production of tau protein. Abnormal accumulation of tau in the brain is a hallmark of Alzheimer's disease and is associated with neurodegeneration and cognitive decline. BIIB080 is currently being evaluated in a Phase 2 clinical study (NCT05399888) in individuals with early Alzheimer's disease.
In December 2019, Biogen exercised a license option with Ionis Pharmaceuticals and obtained a worldwide, exclusive, royalty-bearing license to develop and commercialize BIIB080 (tau ASO).

About Biogen
Founded in 1978, Biogen is a leading biotechnology company that pioneers innovative science to deliver new medicines to transform patient's lives and to create value for shareholders and our communities. We apply deep understanding of human biology and leverage different modalities to advance first-in-class treatments or therapies that deliver superior outcomes. Our approach is to take bold risks, balanced with return on investment to deliver long-term growth.

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This news release contains forward-looking statements, including about the potential clinical effects of lecanemab; the potential benefits, safety and efficacy of lecanemab ; potential regulatory discussions, submissions and approvals and the timing thereof; the treatment of Alzheimer's disease; the anticipated benefits and potential of Biogen's collaboration arrangements with Eisai; the potential of Biogen's commercial business and pipeline programs, including lecanemab; and risks and uncertainties associated with drug development and commercialization. These forward-looking statements may be accompanied by such words as "aim," "anticipate," "believe," "contemplate," "continue," "could," "estimate," "expect," "forecast," "goal," "guidance", "hope," "intend," "may," "objective," "plan," "possible," "potential," "predict," "project," "prospect," "should," "target," "will," "would": and other words and terms of similar meaning. Drug development and commercialization involve a high degree of risk, and only a small number of research and development programs result in commercialization of a product. Results in early-stage clinical trials may not be indicative of full results or results from later stage or larger scale clinical trials and do not ensure regulatory approval. You should not place undue reliance on these statements. Given their forward-looking nature, these statements involve substantial risks and uncertainties that may be based on inaccurate assumptions and could cause actual results to differ materially from those reflected in such statements.

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