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Identifying patients at high risk of developing severe preeclampsia can lead to better prediction, earlier interventions and reduced adverse outcomes.1 In the United States, preeclampsia has increased 25% in the last two decades and is a leading cause of maternal and infant illness and death,2 disproportionately affecting Black women.3 With an extensive U.S. installation base of more than 4,000 cobas® analyzers and a high degree of menu consolidation across various indications, clinicians are supported in making faster, more efficient clinical decisions. INDIANAPOLIS, Feb. 13, 2025 /PRNewswire/ -- Roche announced today that the Roche Elecsys® sFlt-1/PlGF ratio for preeclampsia has received 510(k) clearance from the United States Food and Drug Administration (FDA). The ratio is a prognostic test intended to stratify hospitalized pregnant women with hypertensive disorders of pregnancy into low- and high-risk categories for developing severe preeclampsia within two weeks of testing. Identifying patients at high risk for severe preeclampsia can lead to better prediction, earlier interventions and reduced adverse outcomes.1 In the U.S., preeclampsia has increased 25% in the last two decades and is a leading cause of maternal and fetal illness and death.2 Black women in particular experience higher rates of maternal and adverse fetal and neonatal outcomes than other racial and ethnic groups and are at greater risk for developing hypertensive disorders of pregnancy than other pregnant women.3 "There is a great need for highly reliable tools, such as the Elecsys sFlt-1/PlGF ratio, to address severe preeclampsia," said Brad Moore, president and CEO of Roche Diagnostics North America. "We are eager to partner with our customers so this prognostic test can help clinicians plan care and improve patient outcomes." sFlt-1 and PlGF are key biomarkers in the formation of blood vessels during pregnancy. However, an angiogenic imbalance of these key biomarkers has been proven to play an important role in the development of preeclampsia. Their concentrations in maternal serum are altered even before the onset of the disease, making them a valuable tool for predicting preeclampsia progression.4,5 Nearly 70% of women with a sFlt-1/PlGF ratio greater than 38 delivered their babies within two weeks.1 "The current clinical diagnostic criteria are poor in predicting, with accuracy, the development of preeclampsia among patients with hypertensive disorders of pregnancy," said Sarosh Rana, M.D., MPH, FACOG, University of Chicago Medicine. "The clearance of this ratio provides clinicians with an additional tool to predict the risk of severe preeclampsia and support clinical management by increasing surveillance in high-risk patients or prolonging pregnancy in low-risk patients, ultimately preventing adverse maternal, fetal and neonatal outcomes." Preeclampsia is defined as the new onset of hypertension and proteinuria after 20 weeks of gestation, or in the absence of proteinuria, new-onset hypertension and any of the following: thrombocytopenia, renal insufficiency, impaired liver function, pulmonary edema, or new onset of headache unresponsive to medication.6 Preeclampsia can be treated only by removal of the placenta at delivery.6 The clinical presentation of preeclampsia and the subsequent clinical course of the disorder can vary tremendously, making prediction, diagnosis and assessment of progression difficult.6 "The FDA clearance of the sFlt-1/PlGF ratio on Roche platforms is a major milestone in the quest to solve preeclampsia," said Ravi Thadhani, M.D., MPH, executive vice president of Health Affairs at Emory University. "This test will give clinicians an additional tool to stratify women at highest risk for the development of severe preeclampsia. Preeclampsia biomarker testing has the potential to spur innovation in new therapies that are sorely needed for these patients." Preeclampsia and its symptoms, such as headaches, visual changes, epigastric pain, and shortness of breath,6 have warning signs that are often overlooked and have devastating and lasting impact on mothers and babies if not properly managed.7 Impacts can include maternal organ damage and an increased risk of future heart failure, preterm birth6 and avoidable mental trauma.8 Hospitalization is typically recommended to evaluate the potential for progression to severe disease. Standard diagnostic markers for preeclampsia are often nonspecific and may not accurately predict the severity of the condition or associated adverse outcomes in the subsequent days and weeks.7 The preeclampsia ratio aligns with Roche's commitment to lead with science in order to develop transformational solutions that improve patient outcomes and simplify lab operations. Roche provides an unrivaled ability to scale access to testing at speed for those who need it most. With an extensive U.S. installation base of more than 4,000 cobas® analyzers and a high degree of menu consolidation across various indications, clinicians are supported in making faster, more efficient clinical decisions, providing the ability to scale testing at speed for even more women. About Preeclampsia Preeclampsia is a serious multi-system complication of pregnancy, occurring in 3% to 4% of pregnancies in the U.S., and remains one of the leading causes of maternal and perinatal morbidity and mortality worldwide.7 Preeclampsia can also have negative effects on the fetus and newborn, resulting in complications such as intrauterine growth restriction, low birth weight and stillbirth. These complications often necessitate early induction of labor or cesarean delivery, leading to preterm birth.9 Each year in the U.S., there are 4 million pregnancies, of which 120,000 to 160,000 are affected by preeclampsia. From 2017-2019, hypertensive disorders of pregnancy – including gestational hypertension, chronic hypertension, preeclampsia and superimposed preeclampsia – accounted for 6.3% of pregnancy-related deaths in the U.S.10 In 2022, there were approximately 22 maternal deaths for every 100,000 live births in the U.S. – far above that of other high-income countries.11 About Elecsys sFlt-1/PlGF Ratio The Elecsys sFlt-1/PlGF ratio for preeclampsia is an FDA-cleared test to clinically assess the progression of preeclampsia.12 The preeclampsia ratio supports the management of pregnant patients with a singleton pregnancy, and is intended to help clinicians stratify hospitalized patients into low- and high-risk categories for developing severe preeclampsia within two weeks of presentation.12 Identification of high-risk preeclampsia patients can lead to better prediction, earlier interventions and reduced adverse outcomes.1,5,13 The Elecsys sFlt-1 and Elecsys PlGF assays are provided in separate kits. The ratio must be calculated using Elecsys sFlt 1 and Elecsys PlGF results obtained on the same patient sample and the same cobas immunoassay analyzer per the intended use. The assay results should be used only in conjunction with information available from clinical evaluations and other standard-of-care procedures. The test result is not to be used to replace clinical judgment. About Roche Founded in 1896 in Basel, Switzerland, as one of the first industrial manufacturers of branded medicines, Roche has grown into the world's largest biotechnology company and the global leader in in-vitro diagnostics. The company pursues scientific excellence to discover and develop medicines and diagnostics for improving and saving the lives of people around the world. We are a pioneer in personalized healthcare and want to further transform how healthcare is delivered to have an even greater impact. To provide the best care for each person, we partner with many stakeholders and combine our strengths in Diagnostics and Pharma with data insights from the clinical practice. For over 125 years, sustainability has been an integral part of Roche's business. As a science-driven company, our greatest contribution to society is developing innovative medicines and diagnostics that help people live healthier lives. Roche is committed to the Science Based Targets initiative and the Sustainable Markets Initiative to achieve net zero by 2045. Genentech, in the United States, is a wholly owned member of the Roche Group. Roche is the majority shareholder in Chugai Pharmaceutical, Japan. For more information, please visit . All trademarks used or mentioned in this release are protected by law. References 1. Berg A, Bautista M, Guo G, et al. Circulating angiogenic factors for stratifying the risk of preeclampsia with severe features. SMFM Global Meeting 2024. Pregnancy 2025. 2. Cameron, et al. Trends in the incidence of new-onset hypertensive disorders of pregnancy among rural and urban areas in the United States, 2007 to 2019. J Am Heart Assoc. 2022;11:e023791. 3. Davis NL, Smoots AN, Goodman DA. Pregnancy-Related Deaths: Data from 14 U.S. Maternal Mortality Review Committees, 2008-2017. Atlanta, GA: Centers for Disease Control and Prevention, U.S. Department of Health and Human Services;2019. 4. Levine RJ, et al. Circulating angiogenic factors and the risk of preeclampsia. N Engl J Med 2004;350:672–83. 5. Zeisler H, et al. Predictive value of the sFlt-1:PlGF ratio in women with suspected preeclampsia. N Engl J Med 2016;374:13–22. 6. Gestational hypertension and preeclampsia. ACOG Practice Bulletin No. 222. American College of Obstetricians and Gynecologists. Obstet Gynecol 2020;135:e237–60. 7. Burwick RM, Rodriguez MH. Angiogenic Biomarkers in Preeclampsia. Obstet Gynecol. 2024;143(4):515-523. 8. Not Just Physical: The Psychological Burden Of Preeclampsia And HELLP Syndrome. 9. Backes CH, et al. Maternal Preeclampsia and Neonatal Outcomes. J Pregnancy. 2011;214365. 10. Pregnancy Mortality Surveillance System. 11. Hoyert DL. Maternal mortality rates in the United States, 2022. NCHS Health E-Stats. 2024. 12. Method Sheet Elecsys sFlt-1/PlGF ratio for preeclampsia. 2025 v 1.0. English. 13. Thadhani, et al. Circulating angiogenic factor levels in hypertensive disorders of pregnancy. NEJM Evid 2022;1:(12). For Further Information Roche Diagnostics U.S. Media Relations [email protected] Jennifer Hoopingarner 1-317-797-9741 [email protected] Gina Goodenough 1-317-734-7171 [email protected] SOURCE Roche Diagnostics WANT YOUR COMPANY'S NEWS FEATURED ON PRNEWSWIRE.COM? 440k+ Newsrooms & Influencers 9k+ Digital Media Outlets 270k+ Journalists Opted In GET STARTED

Once every four weeks maintenance dosing may be easier for patients and care partners to continue treatment Alzheimer's disease progression does not stop after plaque clearance; ongoing treatment with LEQEMBI can slow disease progression and prolong the benefits of therapy TOKYO and CAMBRIDGE, Mass., Jan. 26, 2025 /PRNewswire/ -- Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, "Eisai") and Biogen Inc. (Nasdaq: BIIB, Corporate headquarters: Cambridge, Massachusetts, CEO: Christopher A. Viehbacher, "Biogen") announced today that the U.S. Food and Drug Administration (FDA) has approved the Supplemental Biologics License Application (sBLA) for once every four weeks lecanemab-irmb (U.S. brand name: LEQEMBI®) intravenous (IV) maintenance dosing. LEQEMBI is indicated for the treatment of Alzheimer's disease (AD) in patients with mild cognitive impairment (MCI) or mild dementia stage of disease (collectively referred to as early AD) in the U.S. After 18 months of once every two weeks initiation phase, a transition to the maintenance dosing regimen of 10 mg/kg once every four weeks may be considered or the regimen of 10 mg/kg once every two weeks may be continued. The sBLA is based on modeling of observed data from the Phase 2 study (Study 201) and its long-term extension (LTE) as well as the Clarity AD study (Study 301) and its LTE study. Modeling simulations predict that transitioning to once every four weeks maintenance dosing after 18 months of once every two weeks treatment will maintain clinical and biomarker benefits of therapy. AD is a progressive, relentless disease caused by a continuous underlying neurotoxic process that begins before and continues after plaque removal.1,2,3 Only LEQEMBI works to fight AD in two ways: continuously clearing protofibrils and rapidly clearing plaque. This is important because with continuous administration, LEQEMBI clears highly toxic protofibrils* which can continue to cause neuronal injury even after the amyloid-beta (Aβ) plaque has been cleared from the brain. Importance of Ongoing Treatment Data from the off-treatment period between the Study 201 (Phase 2) core study and LTE showed that discontinuation of treatment is associated with reaccumulation of amyloid PET and plasma and CSF biomarkers, and reversion to placebo rate of clinical decline.4 For maintenance treatment, once every four weeks dosing regimen may be easier than once every two weeks dosing for patients and care partners to continue treatment for early AD. Ongoing treatment can slow disease progression and prolong the benefit of therapy,4 with the goal of helping patients maintain who they are for longer. In the Clarity AD core study (18 months), the mean change from baseline between the once every two weeks lecanemab treated group and the placebo group was -0.45 (P<0.0001) on the primary endpoint of the Clinical Dementia Rating-Sum of Boxes (CDR-SB) global cognitive and functional scale. Over three years of treatment across the Clarity AD core study and LTE, LEQEMBI reduced cognitive decline on the CDR-SB by -0.95** relative to a matched natural history cohort, showing clinically meaningful benefit for early AD patients. A change from 0.5 to 1 on the CDR score domains of Memory, Community Affairs and Home/Hobbies is the difference between slight impairment and loss of independence, such as people's ability to be left alone, remember recent events, participate in daily activities, complete household chores, function independently and engage in hobbies and intellectual interests. LEQEMBI is approved in the U.S., Japan, China, South Korea, Hong Kong, Israel, UAE, Great Britain, Mexico and Macau. In November 2024, the treatment received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommending approval. Eisai has submitted applications for approval of lecanemab in 17 countries and regions. Additionally, the 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. Eisai serves as the lead for lecanemab's development and regulatory submissions globally with both Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority. *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 **The lecanemab group was compared to the expected decline based on the Alzheimer's Disease Neuroimaging Initiative (ADNI) group. ADNI is a clinical research project launched in 2005 to develop methods to predict the onset of AD and to confirm the effectiveness of treatments. The ADNI observational cohort represents the exact population of those in Clarity AD study; matched ADNI participants show similar degree of decline to placebo group out to 18 months, supporting the appropriateness of the matching. INDICATION LEQEMBI® [(lecanemab-irmb) 100 mg/mL injection for intravenous use] is indicated for the treatment of Alzheimer's disease (AD). Treatment with LEQEMBI should be initiated in patients with mild cognitive impairment (MCI) or mild dementia stage of disease, the population in which treatment was initiated in clinical trials. IMPORTANT SAFETY INFORMATION CONTRAINDICATION LEQEMBI is contraindicated in patients with serious hypersensitivity to lecanemab-irmb or to any of the excipients of LEQEMBI. Reactions have included angioedema and anaphylaxis. WARNINGS AND PRECAUTIONS AMYLOID-RELATED IMAGING ABNORMALITIES Medications in this class, including LEQEMBI, can cause ARIA-E, which can be observed on MRI as brain edema or sulcal effusions, and ARIA-H, which includes microhemorrhage and superficial siderosis. ARIA can occur spontaneously in patients with AD, particularly in patients with MRI findings suggestive of cerebral amyloid angiopathy (CAA), such as pretreatment microhemorrhage or superficial siderosis. ARIA-H generally occurs with ARIA-E. Reported ARIA symptoms may include headache, confusion, visual changes, dizziness, nausea, and gait difficulty. Focal neurologic deficits may also occur. Symptoms usually resolve over time. Incidence of ARIA Symptomatic ARIA occurred in 3% and serious ARIA symptoms in 0.7% with LEQEMBI. Clinical ARIA symptoms resolved in 79% of patients during the period of observation. ARIA, including asymptomatic radiographic events, was observed: LEQEMBI, 21%; placebo, 9%. ARIA-E was observed: LEQEMBI, 13%; placebo, 2%. ARIA-H was observed: LEQEMBI, 17%; placebo, 9%. No increase in isolated ARIA-H was observed for LEQEMBI vs placebo. Incidence of ICH ICH >1 cm in diameter was reported in 0.7% with LEQEMBI vs 0.1% with placebo. Fatal events of ICH in patients taking LEQEMBI have been observed. Risk Factors of ARIA and ICH ApoE ε4 Carrier Status Of the patients taking LEQEMBI, 16% were ApoE ε4 homozygotes, 53% were heterozygotes, and 31% were noncarriers. With LEQEMBI, ARIA was higher in ApoE ε4 homozygotes (LEQEMBI: 45%; placebo: 22%) than in heterozygotes (LEQEMBI: 19%; placebo: 9%) and noncarriers (LEQEMBI: 13%; placebo: 4%). Symptomatic ARIA-E occurred in 9% of ApoE ε4 homozygotes vs 2% of heterozygotes and 1% of noncarriers. Serious ARIA events occurred in 3% of ApoE ε4 homozygotes and in ~1% of heterozygotes and noncarriers. The recommendations on management of ARIA do not differ between ApoE ε4 carriers and noncarriers. Radiographic Findings of CAA Neuroimaging findings that may indicate CAA include evidence of prior ICH, cerebral microhemorrhage, and cortical superficial siderosis. CAA has an increased risk for ICH. The presence of an ApoE ε4 allele is also associated with CAA. The baseline presence of at least 2 microhemorrhages or the presence of at least 1 area of superficial siderosis on MRI, which may be suggestive of CAA, have been identified as risk factors for ARIA. Patients were excluded from Clarity AD for the presence of >4 microhemorrhages and additional findings suggestive of CAA (prior cerebral hemorrhage >1 cm in greatest diameter, superficial siderosis, vasogenic edema) or other lesions (aneurysm, vascular malformation) that could potentially increase the risk of ICH. Concomitant Antithrombotic or Thrombolytic Medication In Clarity AD, baseline use of antithrombotic medication (aspirin, other antiplatelets, or anticoagulants) was allowed if the patient was on a stable dose. Most exposures were to aspirin. Antithrombotic medications did not increase the risk of ARIA with LEQEMBI. The incidence of ICH: 0.9% in patients taking LEQEMBI with a concomitant antithrombotic medication vs 0.6% with no antithrombotic and 2.5% in patients taking LEQEMBI with an anticoagulant alone or with antiplatelet medication such as aspirin vs none in patients receiving placebo. Fatal cerebral hemorrhage has occurred in 1 patient taking an anti-amyloid monoclonal antibody in the setting of focal neurologic symptoms of ARIA and the use of a thrombolytic agent. Additional caution should be exercised when considering the administration of antithrombotics or a thrombolytic agent (e.g., tissue plasminogen activator) to a patient already being treated with LEQEMBI. Because ARIA-E can cause focal neurologic deficits that can mimic an ischemic stroke, treating clinicians should consider whether such symptoms could be due to ARIA-E before giving thrombolytic therapy in a patient being treated with LEQEMBI. Caution should be exercised when considering the use of LEQEMBI in patients with factors that indicate an increased risk for ICH and, in particular, patients who need to be on anticoagulant therapy or patients with findings on MRI that are suggestive of CAA. Radiographic Severity With LEQEMBI Most ARIA-E radiographic events occurred within the first 7 doses, although ARIA can occur at any time, and patients can have >1 episode. Maximum radiographic severity of ARIA-E with LEQEMBI was mild in 4%, moderate in 7%, and severe in 1% of patients. Resolution on MRI occurred in 52% of ARIA-E patients by 12 weeks, 81% by 17 weeks, and 100% overall after detection. Maximum radiographic severity of ARIA-H microhemorrhage with LEQEMBI was mild in 9%, moderate in 2%, and severe in 3% of patients; superficial siderosis was mild in 4%, moderate in 1%, and severe in 0.4% of patients. With LEQEMBI, the rate of severe radiographic ARIA-E was highest in ApoE ε4 homozygotes (5%) vs heterozygotes (0.4%) or noncarriers (0%). With LEQEMBI, the rate of severe radiographic ARIA-H was highest in ApoE ε4 homozygotes (13.5%) vs heterozygotes (2.1%) or noncarriers (1.1%). Monitoring and Dose Management Guidelines Baseline brain MRI and periodic monitoring with MRI are recommended. Enhanced clinical vigilance for ARIA is recommended during the first 14 weeks of treatment. Depending on ARIA-E and ARIA-H clinical symptoms and radiographic severity, use clinical judgment when considering whether to continue dosing or to temporarily or permanently discontinue LEQEMBI. If a patient experiences ARIA symptoms, clinical evaluation should be performed, including MRI if indicated. If ARIA is observed on MRI, careful clinical evaluation should be performed prior to continuing treatment. HYPERSENSITIVITY REACTIONS Hypersensitivity reactions, including angioedema, bronchospasm, and anaphylaxis, have occurred with LEQEMBI. Promptly discontinue the infusion upon the first observation of any signs or symptoms consistent with a hypersensitivity reaction and initiate appropriate therapy. INFUSION-RELATED REACTIONS (IRR s) IRRs were observed—LEQEMBI: 26%; placebo: 7%—and most cases with LEQEMBI (75%) occurred with the first infusion. IRRs were mostly mild (69%) or moderate (28%). Symptoms included fever and flu-like symptoms (chills, generalized aches, feeling shaky, and joint pain), nausea, vomiting, hypotension, hypertension, and oxygen desaturation. In the event of an IRR, the infusion rate may be reduced or discontinued, and appropriate therapy initiated as clinically indicated. Consider prophylactic treatment prior to future infusions with antihistamines, acetaminophen, nonsteroidal anti-inflammatory drugs, or corticosteroids. ADVERSE REACTIONS The most common adverse reactions reported in ≥5% with LEQEMBI and ≥2% higher than placebo were IRRs (LEQEMBI: 26%; placebo: 7%), ARIA-H (LEQEMBI: 14%; placebo: 8%), ARIA-E (LEQEMBI: 13%; placebo: 2%), headache (LEQEMBI: 11%; placebo: 8%), superficial siderosis of central nervous system (LEQEMBI: 6%; placebo: 3%), rash (LEQEMBI: 6%; placebo: 4%), and nausea/vomiting (LEQEMBI: 6%; placebo: 4%). Please see full Prescribing Information for LEQEMBI, including Boxed WARNING. Notes to Editors 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.,7 Japan,8 China,9 South Korea,10 Hong Kong,11 Israel,12 the United Arab Emirates,13 the United Kingdom,14 Mexico,15 and Macau. In November 2024, the treatment received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommending approval. Eisai has submitted applications for approval of lecanemab in 17 countries and regions. 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.16,17 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. 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. 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. About Eisai Co., Ltd. Eisai's Corporate Concept is "to give first thought to patients and people in the daily living domain, and to increase the benefits that health care provides." Under this Concept (also known as human health care (hhc) Concept), we aim to effectively achieve social good in the form of relieving anxiety over health and reducing health disparities. With a global network of R&D facilities, manufacturing sites and marketing subsidiaries, we strive to create and deliver innovative products to target diseases with high unmet medical needs, with a particular focus in our strategic areas of Neurology and Oncology. In addition, we demonstrate our commitment to the elimination of neglected tropical diseases (NTDs), which is a target (3.3) of the United Nations Sustainable Development Goals (SDGs), by working on various activities together with global partners. For more information about Eisai, please visit (for global headquarters: Eisai Co., Ltd.), and connect with us on X, LinkedIn and Facebook. The website and social media channels are intended for audiences outside of the UK and Europe. For audiences based in the UK and Europe, please visit and Eisai EMEA LinkedIn. About Biogen Founded in 1978, Biogen is a leading biotechnology company that pioneers innovative science to deliver new medicines to transform patients' 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. The company routinely posts information that may be important to investors on its website at . Follow Biogen on social media – Facebook, LinkedIn, X, YouTube. Biogen Safe Harbor 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 statements may be identified by words such as "aim," "anticipate," "believe," "could," "estimate," "expect," "forecast," "intend," "may," "plan," "possible," "potential," "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 studies may not be indicative of full results or results from later stage or larger scale clinical studies and do not ensure regulatory approval. You should not place undue reliance on these statements. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements, including without limitation unexpected concerns that may arise from additional data, analysis or results obtained during clinical studies; the occurrence of adverse safety events; risks of unexpected costs or delays; the risk of other unexpected hurdles; regulatory submissions may take longer or be more difficult to complete than expected; regulatory authorities may require additional information or further studies, or may fail or refuse to approve or may delay approval of Biogen's drug candidates, including lecanemab; actual timing and content of submissions to and decisions made by the regulatory authorities regarding lecanemab; uncertainty of success in the development and potential commercialization of lecanemab; failure to protect and enforce Biogen's data, intellectual property and other proprietary rights and uncertainties relating to intellectual property claims and challenges; product liability claims; and third party collaboration risks, results of operations and financial condition. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from Biogen's expectations in any forward-looking statement. Investors should consider this cautionary statement as well as the risk factors identified in Biogen's most recent annual or quarterly report and in other reports Biogen has filed with the U.S. Securities and Exchange Commission. These statements speak only as of the date of this news release. Biogen does not undertake any obligation to publicly update any forward-looking statements. References LEQEMBI (lecanemab-irmb) injection, for intravenous use [package insert]. Nutley, NJ: Eisai Inc. Iwatsubo T, Irizarry M, van Dyck C, Sabbagh M, Bateman RJ, Cohen S. Clarity AD: a phase 3 placebo-controlled, double-blind, parallel-group, 18-month study evaluating lecanemab in early Alzheimer's disease. Presented at: CTAD Conference; November 29-December 2, 2022; San Francisco, CA. Hampel H, Hardy J, Blennow K, et al. The amyloid-β pathway in Alzheimer's disease. Mol Psychiatry. 2021;26(10):5481-5503. Eisai presents long-term administration data of lecanemab at the Alzheimer's Association International Conference (AAIC) 2024. Available at: 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. 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. U.S. Food and Drug Administration. 2023. FDA Converts Novel Alzheimer's Disease Treatment to Traditional Approval. Last accessed: October 2024. Reuters. 2023. Japan approves Alzheimer's treatment Leqembi by Eisai and Biogen. Last accessed: October 2024. The Pharma Letter. 2024. Brief - Alzheimer drug Leqembi now approved in China. Last accessed: October 2024. Pharmaceutical Technology. 2024. South Korea's MFDS approves Eisai-Biogen's LEQEMBI for Alzheimer's. Last accessed: October 2024. Pharmaceutical Technology. 2024. Hong Kong approves Leqembi for Alzheimer's treatment. Last accessed: October 2024. BioSpace. 2024. Leqembi approved for the treatment of Alzheimer's disease in Israel. Last accessed: October 2024. United Arab Emirates Ministry of Health & Prevention. 2024. Registered Medical Product Directory. Leqembi. Last accessed: October 2024. BioSpace. 2024. Leqembi authorized for early Alzheimer's disease in Great Britain. Last accessed: October 2024. COFEPRIS authorizes innovative treatment for Alzheimer's patients. Available at: . Last accessed: December 2024. van Dyck, C., et al. Lecanemab in Early Alzheimer's Disease. New England Journal of Medicine. 2023;388:9-21. . 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: . SOURCE Eisai Inc. WANT YOUR COMPANY'S NEWS FEATURED ON PRNEWSWIRE.COM? 440k+ Newsrooms & Influencers 9k+ Digital Media Outlets 270k+ Journalists Opted In GET STARTED

Once every four weeks maintenance dosing may be easier for patients and care partners to continue treatment Alzheimer's disease progression does not stop after plaque clearance; ongoing treatment with LEQEMBI can slow disease progression and prolong the benefits of therapy TOKYO and CAMBRIDGE, Mass., Jan. 26, 2025 (GLOBE NEWSWIRE) -- Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) and Biogen Inc. (Nasdaq: BIIB, Corporate headquarters: Cambridge, Massachusetts, CEO: Christopher A. Viehbacher, “Biogen”) announced today that the U.S. Food and Drug Administration (FDA) has approved the Supplemental Biologics License Application (sBLA) for once every four weeks lecanemab-irmb (U.S. brand name: LEQEMBI®) intravenous (IV) maintenance dosing. LEQEMBI is indicated for the treatment of Alzheimer's disease (AD) in patients with mild cognitive impairment (MCI) or mild dementia stage of disease (collectively referred to as early AD) in the U.S. After 18 months of once every two weeks initiation phase, a transition to the maintenance dosing regimen of 10 mg/kg once every four weeks may be considered or the regimen of 10 mg/kg once every two weeks may be continued. The sBLA is based on modeling of observed data from the Phase 2 study (Study 201) and its long-term extension (LTE) as well as the Clarity AD study (Study 301) and its LTE study. Modeling simulations predict that transitioning to once every four weeks maintenance dosing after 18 months of once every two weeks treatment will maintain clinical and biomarker benefits of therapy. AD is a progressive, relentless disease caused by a continuous underlying neurotoxic process that begins before and continues after plaque removal.1,2,3 Only LEQEMBI works to fight AD in two ways: continuously clearing protofibrils and rapidly clearing plaque. This is important because with continuous administration, LEQEMBI clears highly toxic protofibrils* which can continue to cause neuronal injury even after the amyloid-beta (Aβ) plaque has been cleared from the brain. Importance of Ongoing Treatment Data from the off-treatment period between the Study 201 (Phase 2) core study and LTE showed that discontinuation of treatment is associated with reaccumulation of amyloid PET and plasma and CSF biomarkers, and reversion to placebo rate of clinical decline.4 For maintenance treatment, once every four weeks dosing regimen may be easier than once every two weeks dosing for patients and care partners to continue treatment for early AD. Ongoing treatment can slow disease progression and prolong the benefit of therapy,4 with the goal of helping patients maintain who they are for longer. In the Clarity AD core study (18 months), the mean change from baseline between the once every two weeks lecanemab treated group and the placebo group was -0.45 (P<0.0001) on the primary endpoint of the Clinical Dementia Rating-Sum of Boxes (CDR-SB) global cognitive and functional scale. Over three years of treatment across the Clarity AD core study and LTE, LEQEMBI reduced cognitive decline on the CDR-SB by -0.95** relative to a matched natural history cohort - showing clinically meaningful benefit for early AD patients. A change from 0.5 to 1 on the CDR score domains of Memory, Community Affairs and Home/Hobbies is the difference between slight impairment and loss of independence, such as people's ability to be left alone, remember recent events, participate in daily activities, complete household chores, function independently and engage in hobbies and intellectual interests. A change from 0.5 to 1 on the CDR score domains of Memory, Community Affairs and Home/Hobbies is the difference between slight impairment and loss of independence, such as people's ability to be left alone, remember recent events, participate in daily activities, complete household chores, function independently and engage in hobbies and intellectual interests. LEQEMBI is approved in the U.S., Japan, China, South Korea, Hong Kong, Israel, UAE, Great Britain, Mexico and Macau. In November 2024, the treatment received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommending approval. Eisai has submitted applications for approval of lecanemab in 17 countries and regions. Additionally, the 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. Eisai serves as the lead for lecanemab’s development and regulatory submissions globally with both Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority. *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 **The lecanemab group was compared to the expected decline based on the Alzheimer's Disease Neuroimaging Initiative (ADNI) group. ADNI is a clinical research project launched in 2005 to develop methods to predict the onset of AD and to confirm the effectiveness of treatments. The ADNI observational cohort represents the exact population of those in Clarity AD study; matched ADNI participants show similar degree of decline to placebo group out to 18 months, supporting the appropriateness of the matching. INDICATION LEQEMBI® [(lecanemab-irmb) 100 mg/mL injection for intravenous use] is indicated for the treatment of Alzheimer’s disease (AD). Treatment with LEQEMBI should be initiated in patients with mild cognitive impairment (MCI) or mild dementia stage of disease, the population in which treatment was initiated in clinical trials. IMPORTANT SAFETY INFORMATION Monoclonal antibodies directed against aggregated forms of beta amyloid, including LEQEMBI, can cause ARIA, characterized as ARIA with edema (ARIA-E) and ARIA with hemosiderin deposition (ARIA-H). Incidence and timing of ARIA vary among treatments. ARIA usually occurs early in treatment and is usually asymptomatic, although serious and life-threatening events, including seizure and status epilepticus, can occur. ARIA can be fatal. Serious intracerebral hemorrhages (ICH) >1 cm, some of which have been fatal, have been observed with this class of medications. Because ARIA-E can cause focal neurologic deficits that can mimic an ischemic stroke, consider whether such symptoms could be due to ARIA-E before giving thrombolytic therapy to a patient being treated with LEQEMBI. Apolipoprotein E ε4 (ApoE ε4) Homozygotes: Patients who are ApoE ε4 homozygotes (~15% of patients with AD) treated with this class of medications have a higher incidence of ARIA, including symptomatic, serious, and severe radiographic ARIA, compared to heterozygotes and noncarriers. Testing for ApoE ε4 status should be performed prior to initiation of treatment to inform the risk of developing ARIA. Prior to testing, prescribers should discuss with patients the risk of ARIA across genotypes and the implications of genetic testing results. Prescribers should inform patients that if genotype testing is not performed, they can still be treated with LEQEMBI; however, it cannot be determined if they are ApoE ε4 homozygotes and at higher risk for ARIA. Apolipoprotein E ε4 (ApoE ε4) Homozygotes: Patients who are ApoE ε4 homozygotes (~15% of patients with AD) treated with this class of medications have a higher incidence of ARIA, including symptomatic, serious, and severe radiographic ARIA, compared to heterozygotes and noncarriers. Testing for ApoE ε4 status should be performed prior to initiation of treatment to inform the risk of developing ARIA. Prior to testing, prescribers should discuss with patients the risk of ARIA across genotypes and the implications of genetic testing results. Prescribers should inform patients that if genotype testing is not performed, they can still be treated with LEQEMBI; however, it cannot be determined if they are ApoE ε4 homozygotes and at higher risk for ARIA. CONTRAINDICATION LEQEMBI is contraindicated in patients with serious hypersensitivity to lecanemab-irmb or to any of the excipients of LEQEMBI. Reactions have included angioedema and anaphylaxis. WARNINGS AND PRECAUTIONS AMYLOID-RELATED IMAGING ABNORMALITIES Medications in this class, including LEQEMBI, can cause ARIA-E, which can be observed on MRI as brain edema or sulcal effusions, and ARIA-H, which includes microhemorrhage and superficial siderosis. ARIA can occur spontaneously in patients with AD, particularly in patients with MRI findings suggestive of cerebral amyloid angiopathy (CAA), such as pretreatment microhemorrhage or superficial siderosis. ARIA-H generally occurs with ARIA-E. Reported ARIA symptoms may include headache, confusion, visual changes, dizziness, nausea, and gait difficulty. Focal neurologic deficits may also occur. Symptoms usually resolve over time. Incidence of ARIASymptomatic ARIA occurred in 3% and serious ARIA symptoms in 0.7% with LEQEMBI. Clinical ARIA symptoms resolved in 79% of patients during the period of observation. ARIA, including asymptomatic radiographic events, was observed: LEQEMBI, 21%; placebo, 9%. ARIA-E was observed: LEQEMBI, 13%; placebo, 2%. ARIA-H was observed: LEQEMBI, 17%; placebo, 9%. No increase in isolated ARIA-H was observed for LEQEMBI vs placebo. Incidence of ICHICH >1 cm in diameter was reported in 0.7% with LEQEMBI vs 0.1% with placebo. Fatal events of ICH in patients taking LEQEMBI have been observed. Risk Factors of ARIA and ICH ApoE ε4 Carrier StatusOf the patients taking LEQEMBI, 16% were ApoE ε4 homozygotes, 53% were heterozygotes, and 31% were noncarriers. With LEQEMBI, ARIA was higher in ApoE ε4 homozygotes (LEQEMBI: 45%; placebo: 22%) than in heterozygotes (LEQEMBI: 19%; placebo: 9%) and noncarriers (LEQEMBI: 13%; placebo: 4%). Symptomatic ARIA-E occurred in 9% of ApoE ε4 homozygotes vs 2% of heterozygotes and 1% of noncarriers. Serious ARIA events occurred in 3% of ApoE ε4 homozygotes and in ~1% of heterozygotes and noncarriers. The recommendations on management of ARIA do not differ between ApoE ε4 carriers and noncarriers. Radiographic Findings of CAANeuroimaging findings that may indicate CAA include evidence of prior ICH, cerebral microhemorrhage, and cortical superficial siderosis. CAA has an increased risk for ICH. The presence of an ApoE ε4 allele is also associated with CAA. The baseline presence of at least 2 microhemorrhages or the presence of at least 1 area of superficial siderosis on MRI, which may be suggestive of CAA, have been identified as risk factors for ARIA. Patients were excluded from Clarity AD for the presence of >4 microhemorrhages and additional findings suggestive of CAA (prior cerebral hemorrhage >1 cm in greatest diameter, superficial siderosis, vasogenic edema) or other lesions (aneurysm, vascular malformation) that could potentially increase the risk of ICH. Concomitant Antithrombotic or Thrombolytic MedicationIn Clarity AD, baseline use of antithrombotic medication (aspirin, other antiplatelets, or anticoagulants) was allowed if the patient was on a stable dose. Most exposures were to aspirin. Antithrombotic medications did not increase the risk of ARIA with LEQEMBI. The incidence of ICH: 0.9% in patients taking LEQEMBI with a concomitant antithrombotic medication vs 0.6% with no antithrombotic and 2.5% in patients taking LEQEMBI with an anticoagulant alone or with antiplatelet medication such as aspirin vs none in patients receiving placebo. Fatal cerebral hemorrhage has occurred in 1 patient taking an anti-amyloid monoclonal antibody in the setting of focal neurologic symptoms of ARIA and the use of a thrombolytic agent. Additional caution should be exercised when considering the administration of antithrombotics or a thrombolytic agent (e.g., tissue plasminogen activator) to a patient already being treated with LEQEMBI. Because ARIA-E can cause focal neurologic deficits that can mimic an ischemic stroke, treating clinicians should consider whether such symptoms could be due to ARIA-E before giving thrombolytic therapy in a patient being treated with LEQEMBI. Caution should be exercised when considering the use of LEQEMBI in patients with factors that indicate an increased risk for ICH and, in particular, patients who need to be on anticoagulant therapy or patients with findings on MRI that are suggestive of CAA. Radiographic Severity With LEQEMBIMost ARIA-E radiographic events occurred within the first 7 doses, although ARIA can occur at any time, and patients can have >1 episode. Maximum radiographic severity of ARIA-E with LEQEMBI was mild in 4%, moderate in 7%, and severe in 1% of patients. Resolution on MRI occurred in 52% of ARIA-E patients by 12 weeks, 81% by 17 weeks, and 100% overall after detection. Maximum radiographic severity of ARIA-H microhemorrhage with LEQEMBI was mild in 9%, moderate in 2%, and severe in 3% of patients; superficial siderosis was mild in 4%, moderate in 1%, and severe in 0.4% of patients. With LEQEMBI, the rate of severe radiographic ARIA-E was highest in ApoE ε4 homozygotes (5%) vs heterozygotes (0.4%) or noncarriers (0%). With LEQEMBI, the rate of severe radiographic ARIA-H was highest in ApoE ε4 homozygotes (13.5%) vs heterozygotes (2.1%) or noncarriers (1.1%). Monitoring and Dose Management GuidelinesBaseline brain MRI and periodic monitoring with MRI are recommended. Enhanced clinical vigilance for ARIA is recommended during the first 14 weeks of treatment. Depending on ARIA-E and ARIA-H clinical symptoms and radiographic severity, use clinical judgment when considering whether to continue dosing or to temporarily or permanently discontinue LEQEMBI. If a patient experiences ARIA symptoms, clinical evaluation should be performed, including MRI if indicated. If ARIA is observed on MRI, careful clinical evaluation should be performed prior to continuing treatment. HYPERSENSITIVITY REACTIONSHypersensitivity reactions, including angioedema, bronchospasm, and anaphylaxis, have occurred with LEQEMBI. Promptly discontinue the infusion upon the first observation of any signs or symptoms consistent with a hypersensitivity reaction and initiate appropriate therapy. INFUSION-RELATED REACTIONS (IRRs)IRRs were observed—LEQEMBI: 26%; placebo: 7%—and most cases with LEQEMBI (75%) occurred with the first infusion. IRRs were mostly mild (69%) or moderate (28%). Symptoms included fever and flu-like symptoms (chills, generalized aches, feeling shaky, and joint pain), nausea, vomiting, hypotension, hypertension, and oxygen desaturation.In the event of an IRR, the infusion rate may be reduced or discontinued, and appropriate therapy initiated as clinically indicated. Consider prophylactic treatment prior to future infusions with antihistamines, acetaminophen, nonsteroidal anti-inflammatory drugs, or corticosteroids. ADVERSE REACTIONSThe most common adverse reactions reported in ≥5% with LEQEMBI and ≥2% higher than placebo were IRRs (LEQEMBI: 26%; placebo: 7%), ARIA-H (LEQEMBI: 14%; placebo: 8%), ARIA-E (LEQEMBI: 13%; placebo: 2%), headache (LEQEMBI: 11%; placebo: 8%), superficial siderosis of central nervous system (LEQEMBI: 6%; placebo: 3%), rash (LEQEMBI: 6%; placebo: 4%), and nausea/vomiting (LEQEMBI: 6%; placebo: 4%). Please see full Prescribing Information for LEQEMBI, including Boxed WARNING. 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.,7 Japan,8 China,9 South Korea,10 Hong Kong,11 Israel,12 the United Arab Emirates,13 the United Kingdom,14 Mexico,15 and Macau. In November 2024, the treatment received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommending approval. Eisai has submitted applications for approval of lecanemab in 17 countries and regions. 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.16,17 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 ADEisai 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 ADSince 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 Eisai Co., Ltd.Eisai's Corporate Concept is "to give first thought to patients and people in the daily living domain, and to increase the benefits that health care provides." Under this Concept (also known as human health care (hhc) Concept), we aim to effectively achieve social good in the form of relieving anxiety over health and reducing health disparities. With a global network of R&D facilities, manufacturing sites and marketing subsidiaries, we strive to create and deliver innovative products to target diseases with high unmet medical needs, with a particular focus in our strategic areas of Neurology and Oncology. In addition, we demonstrate our commitment to the elimination of neglected tropical diseases (NTDs), which is a target (3.3) of the United Nations Sustainable Development Goals (SDGs), by working on various activities together with global partners. For more information about Eisai, please visit www.eisai.com (for global headquarters: Eisai Co., Ltd.), and connect with us on X, LinkedIn and Facebook. The website and social media channels are intended for audiences outside of the UK and Europe. For audiences based in the UK and Europe, please visit www.eisai.eu and Eisai EMEA LinkedIn. 5. About BiogenFounded in 1978, Biogen is a leading biotechnology company that pioneers innovative science to deliver new medicines to transform patients’ 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. The company routinely posts information that may be important to investors on its website at www.biogen.com. Follow Biogen on social media – Facebook, LinkedIn, X, YouTube. Biogen Safe HarborThis 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 statements may be identified by words such as "aim," "anticipate," "believe," "could," "estimate," "expect," "forecast," "intend," "may," "plan," "possible," "potential," "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 studies may not be indicative of full results or results from later stage or larger scale clinical studies and do not ensure regulatory approval. You should not place undue reliance on these statements. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements, including without limitation unexpected concerns that may arise from additional data, analysis or results obtained during clinical studies; the occurrence of adverse safety events; risks of unexpected costs or delays; the risk of other unexpected hurdles; regulatory submissions may take longer or be more difficult to complete than expected; regulatory authorities may require additional information or further studies, or may fail or refuse to approve or may delay approval of Biogen's drug candidates, including lecanemab; actual timing and content of submissions to and decisions made by the regulatory authorities regarding lecanemab; uncertainty of success in the development and potential commercialization of lecanemab; failure to protect and enforce Biogen's data, intellectual property and other proprietary rights and uncertainties relating to intellectual property claims and challenges; product liability claims; and third party collaboration risks, results of operations and financial condition. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from Biogen's expectations in any forward-looking statement. Investors should consider this cautionary statement as well as the risk factors identified in Biogen's most recent annual or quarterly report and in other reports Biogen has filed with the U.S. Securities and Exchange Commission. These statements speak only as of the date of this news release. Biogen does not undertake any obligation to publicly update any forward-looking statements. References