Track market-moving stories before they get noisy

–4-year data from the Phase 1/2a open-label extension (OLE) studies support the potential disease-modifying effects of zorevunersen–

–Improvements in cognition and behavior sustained through 4 years, in addition to durable seizure reductions and a generally well-tolerated safety profile–

–New data from sub-analyses of patients treated with zorevunersen in the Phase 1/2a OLEs include effects on severe seizures and quality of life–

BEDFORD, Mass. and CAMBRIDGE, Mass., Sept. 01, 2026 (GLOBE NEWSWIRE) -- Stoke Therapeutics, Inc. (Nasdaq: STOK), a biotechnology company dedicated to restoring protein expression by harnessing the body’s potential with RNA medicine, and Biogen Inc. (Nasdaq: BIIB) today announced presentations of data at the 16th European Epilepsy Congress (EEC), taking place September 5–9 in Athens, Greece. These data support the potential of zorevunersen as a first-in-class disease-modifying treatment for Dravet syndrome. The global, pivotal Phase 3 EMPEROR study is underway to evaluate the safety and efficacy of zorevunersen, and results are anticipated in the third quarter of 2027.

Data to be shared at EEC include the first medical meeting presentation of 4-year results from the ongoing Phase 1/2a open-label extension (OLE) studies of zorevunersen in patients with Dravet syndrome. Improvements in cognition and behavior were sustained through 4 years, in addition to durable seizure reductions and a generally well-tolerated safety profile. New exploratory sub-analyses show effects on the most severe seizure types, which are the leading risk factor for sudden unexpected death in epilepsy (SUDEP)1, as well as improvements in quality of life for patients treated with zorevunersen.

"Together with the Phase 1/2a results, the ongoing OLE studies provide more than 5 years of clinical data that continue to deepen our understanding of zorevunersen’s long-term safety and benefits,” said Barry Ticho, M.D., Ph.D., Chief Medical Officer of Stoke Therapeutics. “These data have consistently shown substantial and durable seizure reductions with continued treatment. For the first time at EEC, we will share an additional analysis showing zorevunersen’s effects on the most severe seizure types. Alongside continuing improvements in cognition and behavior over time, these new findings support the potential of zorevunersen to change the course of Dravet syndrome by targeting the underlying genetic cause of the disease.”

“Dravet syndrome is a devastating neurodevelopmental disease that impacts nearly every aspect of daily life for patients and those who care for them,” said Stephanie Fradette, Pharm.D., Head of the Rare Neurology Development Unit at Biogen. “The data shared at EEC provide continued support for the potential of zorevunersen to give people living with Dravet syndrome the possibility of more neurotypical development. We look forward to discussing these data with the epilepsy community at EEC.”

Details of the EEC presentations are as follows:

Title: Zorevunersen Demonstrates Disease-Modifying Potential in Patients with Dravet Syndrome with Improvements in Seizure Burden, Quality of Life, and Overall Clinical Status
Oral Presentation Date & Time: Sunday, September 6, 12:53-1:02 PM EEST/ UTC+3 (5:53-6:02 AM ET)Oral Presenter: J. Helen Cross, MB ChB, Ph.D., Professor, The Prince of Wales’s Chair of Childhood Epilepsy and Head of the Developmental Neuroscience Programme at University College London Great Ormond Street Institute of Child Health, Honorary Consultant in Paediatric Neurology and Past President of the International League Against Epilepsy Title: Zorevunersen Demonstrates Potential as a Disease-Modifying Therapy in Patients with Dravet Syndrome: A Matching-Adjusted Indirect Comparison Between Natural History and Patients Receiving Zorevunersen
Poster Presentation Date & Time: Monday, September 7, 2:00-3:00 PM EEST/ UTC+3 (7:00-8:00 AM ET)Poster Presenter: Andreas Brunklaus, MD, Consultant Paediatric Neurologist at the Royal Hospital for Children in Glasgow, Honorary Professor at the University of Glasgow
Poster Number: P0803 Title: Zorevunersen Demonstrates Potential as a Disease-Modifying Therapy in Patients with Dravet Syndrome Through Durable Seizure Reduction and Improvements in Cognition, Behavior, and Quality of Life Through 48 Months of Treatment in Open-Label Extension Studies
Poster Presentation Date & Time: Tuesday, September 8, 2:00-3:00 PM EEST/ UTC+3 (7:00-8:00 AM ET)Poster Presenter: Elaine Wirrell​, MD, Director of Pediatric Epilepsy at Mayo Clinic, Director of the Child and Adolescent Neurology Residency Training Program at Mayo Clinic
Poster Number: P0797 Summary of Zorevunersen Safety Data

Following treatment in the Phase 1/2a studies, 93% (75/81) patients continued treatment in one of two OLE studies. As of the 4-year data cutoff, 77% (58/75) patients remained in these studies.Zorevunersen continues to be generally well tolerated, with some patients treated for more than 5 years in the Phase 1/2a and ongoing OLE studies. As of July 31, 2026, more than 930 doses have been administered.Elevated CSF protein lab values occurred in approximately 94% of patients of which 59% have been classified as a treatment-emergent adverse event. Importantly, no serious or severe clinical manifestations have been associated with CSF protein elevations. There have been no reports of hydrocephalus. About Dravet Syndrome
Dravet syndrome is a severe developmental and epileptic encephalopathy (DEE) characterized by recurrent seizures as well as significant cognitive and behavioral impairments. Most cases of Dravet are caused by mutations in one copy of the SCN1A gene, leading to insufficient levels of NaV1.1 protein in neuronal cells in the brain. Even when treated with the best available anti-seizure medicines (ASMs), up to 57 percent of patients with Dravet syndrome do not achieve ≥50 percent reduction in seizure frequency. Complications of the disease often contribute to a poor quality of life for patients and their caregivers. Developmental and cognitive impairments often include intellectual disability, developmental delays, movement and balance issues, language and speech disturbances, growth defects, sleep abnormalities, disruptions of the autonomic nervous system and mood disorders. Compared with the general epilepsy population, people living with Dravet syndrome have a higher risk of sudden unexpected death in epilepsy, or SUDEP; up to 20 percent of children and adolescents with Dravet syndrome die before adulthood due to SUDEP, prolonged seizures, seizure-related accidents or infections 2. Dravet syndrome occurs globally and is not concentrated in a particular geographic area or ethnic group. Currently, it is estimated that up to 38,000 people are living with Dravet syndrome in the U.S. (~16,000), UK, EU-4 and Japan 3. There are no approved disease-modifying therapies for people living with Dravet syndrome.

About Zorevunersen
Zorevunersen is an investigational antisense oligonucleotide that is designed to treat the underlying cause of Dravet syndrome by increasing functional NaV1.1 protein production in brain cells from the unaffected (wild-type) copy of the SCN1A gene. This highly differentiated mechanism of action aims to reduce seizure frequency beyond what has been achieved with anti-seizure medicines and to improve neurodevelopment, cognition and behavior. Zorevunersen has demonstrated the potential for disease modification and has been granted orphan drug designation by the FDA and the EMA. The FDA has also granted zorevunersen rare pediatric disease designation and Breakthrough Therapy Designation for the treatment of Dravet syndrome with a confirmed mutation not associated with gain-of-function in the SCN1A gene, and China’s Center for Drug Evaluation has granted zorevunersen Breakthrough Therapy Designation. Stoke has a strategic collaboration with Biogen (Nasdaq: BIIB) to develop and commercialize zorevunersen for Dravet syndrome. Under the collaboration, Stoke retains exclusive rights for zorevunersen in the United States, Canada, and Mexico; Biogen receives exclusive rest of world commercialization rights. Zorevunersen is currently in clinical development, and its safety and efficacy have not been evaluated by any regulatory authority.

About the Phase 1/2a and Open-Label Extension Studies
Two Phase 1/2a open-label, multicenter studies evaluated the effects of zorevunersen in patients with highly refractory Dravet syndrome ages 2 to 18 years (N=81). Primary endpoints were the safety profile, plasma pharmacokinetics (PK) and exposure in cerebrospinal fluid (CSF) of single and multiple doses of zorevunersen. Secondary endpoints included percentage change from baseline in major motor seizure frequency, overall clinical status (a measure of patients’ overall functioning) and quality of life. The ADMIRAL Phase 1/2a study included an exploratory endpoint to evaluate changes in neurodevelopmental status (cognition & behavior) as measured by Vineland Adaptive Behavior Scales, Third Edition (Vineland-3). The Phase 1/2a studies were completed in November 2023. Following treatment in the Phase 1/2a studies, eligible patients continued treatment with zorevunersen every four months in one of two OLEs. There was at least a 6-month gap between the last dose administered in the Phase 1/2a studies and the first dose administered in the OLEs. The primary endpoints are the safety profile of multiple doses of zorevunersen. Secondary endpoints include PK parameters, percentage change from baseline in major motor seizure frequency, change in overall clinical status, and change from baseline in quality of life. Exploratory endpoints include changes in neurodevelopment status as measured by Vineland-3. Results from the Phase 1/2a and OLE studies were published in The New England Journal of Medicine (NEJM) in March 2026. The OLE studies are ongoing.

About Stoke Therapeutics
Stoke Therapeutics (Nasdaq: STOK), is a biotechnology company dedicated to restoring protein expression by harnessing the body’s potential with RNA medicine. Using Stoke’s proprietary TANGO (Targeted Augmentation of Nuclear Gene Output) approach, Stoke is developing antisense oligonucleotides (ASOs) to selectively restore naturally-occurring protein levels. Stoke’s first medicine in development, zorevunersen, has demonstrated the potential for disease modification in patients with Dravet syndrome and is currently being evaluated in a Phase 3 study. Stoke’s initial focus are diseases of the central nervous system and the eye that are caused by a loss of ~50% of normal protein levels (haploinsufficiency). Proof of concept has been demonstrated in other organs, tissues, and systems, supporting broad potential for Stoke’s proprietary approach. Stoke is headquartered in Bedford, Massachusetts. For more information, visit https://www.stoketherapeutics.com/ or follow us on 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. We routinely post information that may be important to investors on our website at www.biogen.com. Follow us on social media - Facebook, Instagram, LinkedIn, X, YouTube.

Stoke Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to: the ability of zorevunersen to treat the underlying causes of Dravet syndrome and reduce seizures or show improvements in behavior and cognition at the indicated dosing levels or at all; the potential benefits, safety and efficacy of zorevunersen; the design, timing and expected progress of clinical trials, data readouts, regulatory meetings, regulatory decisions and other presentations; and the participation of scientists associated with Stoke making presentations at EEC and the presentation of data at EEC. Statements including words such as “plan,” “potential,” “will,” “continue,” “expect,” or similar words and statements in the future tense are forward-looking statements. These forward-looking statements involve risks and uncertainties, as well as assumptions, which, if they prove incorrect or do not fully materialize, could cause Stoke’s results to differ materially from those expressed or implied by such forward-looking statements, including, but not limited to, risks and uncertainties related to: Stoke’s ability to advance, obtain regulatory approval and ultimately commercialize its product candidates; that if Biogen were to breach or terminate the collaboration, Stoke would not obtain the anticipated financial or other benefits; the possibility that Stoke and Biogen may not be successful in their development of zorevunersen and that, even if successful, they may be unable to successfully commercialize zorevunersen; positive results in a clinical trial may not be replicated in subsequent trials or successes in early stage clinical trials may not be predictive of results in later stage trials; Stoke’s ability to protect its intellectual property; Stoke’s ability to fund development activities and achieve development goals into 2028; and the other risks and uncertainties described under the heading “Risk Factors” in its Annual Report on Form 10-K for the year ended December 31, 2025, its quarterly reports on Form 10-Q, and the other documents it files with the Securities and Exchange Commission. These forward-looking statements speak only as of the date of this press release, and Stoke undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date hereof.

Biogen Safe Harbor
This news release contains forward-looking statements, including, among others, relating to: the potential clinical effects of zorevunersen; the potential for zorevunersen to change the course of Dravet syndrome and improve outcomes for patients; the expected timing of Phase 3 study results; the potential benefits, safety and efficacy of zorevunersen; potential regulatory discussions, submissions and approvals and the timing thereof; the treatment of the underlying causes of Dravet syndrome; the anticipated benefits, risks and potential of Biogen's collaboration arrangements with Stoke Therapeutics; the potential of Biogen's commercial business and pipeline programs, including zorevunersen; and risks and uncertainties associated with drug development and commercialization. These forward-looking statements may be accompanied by such words as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “forecast,” “goal,” “guidance,” “hope,” “intend,” “may,” “objective,” “outlook,” “plan,” “possible,” “potential,” “predict,” “project,” “prospect,” “should,” “target,” “will,” “would” or the negative of these words or 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.

These forward-looking statements are based on management’s current beliefs and assumptions and on information currently available to management. Given their nature, we cannot assure that any outcome expressed in these forward-looking statements will be realized in whole or in part. We caution that these statements are subject to risks and uncertainties, many of which are outside of our control and could cause future events or results to differ materially from those stated or implied in this document, including, among others, uncertainty of our long-term success in developing, licensing, or acquiring other product candidates or additional indications for existing products; expectations, plans, prospects and timing of actions relating to product approvals, approvals of additional indications for our existing products, sales, pricing, growth, reimbursement and launch of our marketed and pipeline products; the potential impact of increased product competition in the biopharmaceutical and healthcare industry, as well as any other markets in which we compete, including increased competition from new originator therapies, generics, prodrugs and biosimilars of existing products and products approved under abbreviated regulatory pathways; our ability to effectively implement our corporate strategy; difficulties in obtaining and maintaining adequate coverage, pricing, and reimbursement for our products; the drivers for growing our business, including our dependence on collaborators and other third parties for the development, regulatory approval, and commercialization of products and other aspects of our business, which are outside of our full control; risks related to commercialization of biosimilars, which is subject to such risks related to our reliance on third-parties, intellectual property, competitive and market challenges and regulatory compliance; the risk that positive results in a clinical trial may not be replicated in subsequent or confirmatory trials or success in early stage clinical trials may not be predictive of results in later stage or large scale clinical trials or trials in other potential indications; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; and the occurrence of adverse safety events, restrictions on use with our products, or product liability claims; and any other risks and uncertainties that are described in other reports we have filed with the U.S. Securities and Exchange Commission, which are available on the SEC’s website at www.sec.gov.

These statements speak only as of the date of this press release and are based on information and estimates available to us at this time. Should known or unknown risks or uncertainties materialize or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. Investors are cautioned not to put undue reliance on forward-looking statements. A further list and description of risks, uncertainties and other matters can be found in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 and in our subsequent reports on Form 10-Q. Except as required by law, we do not undertake any obligation to publicly update any forward-looking statements whether as a result of any new information, future events, changed circumstances or otherwise.

Biogen Digital Media Disclosure
From time to time, we have used, or expect in the future to use, our investor relations website (investors.biogen.com), the Biogen LinkedIn account (linkedin.com/company/biogen-) and the Biogen X account (https://x.com/biogen) as a means of disclosing information to the public in a broad, non-exclusionary manner, including for purposes of the SEC’s Regulation Fair Disclosure (Reg FD). Accordingly, investors should monitor our investor relations website and these social media channels in addition to our press releases, SEC filings, public conference calls and websites, as the information posted on them could be material to investors.

References:

Beniczky, S. et al. Updated classification of epileptic seizures: Position paper of the International League Against Epilepsy. Epilepsia. 2025; 1804–1823.Symonds, J. et al. Early childhood epilepsies: epidemiology, classification, aetiology, and socio-economic determinants. Brain. 2021;144(9):2879-2891.Based on Stoke Therapeutics’ preliminary estimates, which scaled annual incidence to prevalence using country-specific live birth rates over the past 85 years and adjusted for Dravet-specific mortality. The estimate is based on incidence rates published by Wu et al., Pediatrics, 2015.

LEQEMBI IQLIK is the first-of-its-kind anti-amyloid treatment worldwide offering at-home dosing
for initiation and maintenance (approved in the U.S.)

, /PRNewswire/ -- Eisai Co., Ltd. and Biogen Inc. (Nasdaq: BIIB), announced today that once weekly lecanemab‑irmb subcutaneous injection (brand name: LEQEMBI IQLIK®) is now available in the U.S. for initiation therapy for early Alzheimer's disease (AD) in adults with mild cognitive impairment (MCI) or mild dementia due to AD, collectively referred to as early AD. MCI due to AD is the earliest symptomatic stage of AD and can appear with subtle symptoms such as forgetfulness, confusion, or feeling at a loss for words.1 

LEQEMBI IQLIK is administered via an autoinjector, introducing a convenient alternative to intravenous (IV) dosing from the start of treatment. For initiation, the approved regimen is 500 mg given once weekly as two consecutive 250 mg injections, each delivered in approximately 15 seconds. LEQEMBI IQLIK may also be used for maintenance dosing at 360 mg once weekly after 18 months of IV or subcutaneous (SC) treatment. Throughout the entire treatment course – from initiation through maintenance – patients may receive LEQEMBI either as IV infusion or as SC injection with LEQEMBI IQLIK. Patients may also switch from IV to SC administration, or vice versa, providing greater convenience and flexibility in LEQEMBI administration.

Expanding Treatment Convenience and Flexibility Across the Alzheimer's Disease Care Pathway
The availability of LEQEMBI IQLIK for both initiation and maintenance therapy in the U.S. enhances treatment convenience and flexibility, offering early AD patients and their care partners more control in managing their care while lowering barriers to initiating and continuing treatment with LEQEMBI. LEQEMBI IQLIK may reduce the time spent receiving anti-amyloid therapy via IV infusions. In addition, at-home administration allows patients and their care partners to continue treatment without the burden of clinic visits, making it easier to go out and travel. LEQEMBI IQLIK also has the potential to reduce healthcare resources associated with IV dosing, such as infusion preparation and nurse monitoring. These features may help streamline the overall AD treatment pathway. For ARIA monitoring, as with IV administration, brain magnetic resonance imaging (MRI) is performed prior to initiating treatment and at specified time points after treatment initiation.

Support Resources for LEQEMBI IQLIK
Eisai and Biogen will provide a range of resources to help patients, care partners, healthcare providers, health systems and pharmacies successfully implement and use LEQEMBI IQLIK.

Patient Support
Resources include an Instructions for Use (IFU) video and IQLIK Welcome Kit. The IQLIK Welcome Kit provides a What to Expect Treatment Tracker, an injection reminder magnet, and a Demo Kit to help patients and care partners understand what to expect, prepare for at-home injections, and administer injections safely at home. The LEQEMBI Companion® app will also be available. It brings the information patients and care partners need into one experience, including education about the injection process and tools for tracking each dose.

Patients initiating IQLIK will be encouraged to bring the Welcome Kit to their initial dosing appointment. Kits will be available through: 

The LEQEMBI Specialty Pharmacy Network (CareMed Specialty Pharmacy and Walgreens Specialty Pharmacy)   Integrated Delivery Networks (IDNs) or the prescribing physician  LEQEMBI Companion® - a program offering financial support information and options for eligible patients.   Through the LEQEMBI Specialty Pharmacy Network, patients may receive support with prescription fulfillment, insurance coverage navigation, onboarding, delivery coordination, device-use education, and – if they choose to participate – treatment reminders and educational support during the first six months of therapy. Patients using other eligible specialty pharmacies may have access to similar support, which may vary by pharmacy.

Healthcare Provider Resources
Electronic Health Record (EHR) support materials and a step-by-step Getting Started Guide will help providers navigate the process from prescription submission through therapy initiation.

Financial Assistance
To further support access to LEQEMBI for certain patients who need help paying for their medicines, Eisai's Patient Assistance Program (PAP) will provide LEQEMBI and LEQEMBI IQLIK at no cost, for eligible uninsured patients, who meet financial need and other program criteria.

*The LEQEMBI Companion app was developed to deliver behavior-driven digital support for patients and care partners along their treatment journey, in partnership with Medisafe Ltd., a behavioral patient engagement engine built for complex and specialty therapies. Patients can visit LEQEMBI.com/CompanionAppSignUp to get started.

Eisai serves as the lead for lecanemab's development and regulatory submissions globally with Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

INDICATION
LEQEMBI® 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

WARNING: AMYLOID-RELATED IMAGING ABNORMALITIES (ARIA)

•

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.

•

Consider the benefit of LEQEMBI for the treatment of AD and the potential risk of serious ARIA events when deciding to initiate treatment with LEQEMBI.

CONTRAINDICATION
Contraindicated in patients with serious hypersensitivity to lecanemab-irmb or to any of the excipients. 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 (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.

IRRs can occur during or after the completion of infusion. In the event of an IRR during the infusion, 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 infusion every 2 weeks 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%) The safety profile of subcutaneous LEQEMBI was similar to intravenous infusion. Subcutaneous dosing was associated with mostly localized (erythema, induration, swelling, heat, pain, pruritus, rash, ecchymosis, nodule, and hematoma) and less frequent systemic (headache, chills, fever, and fatigue) injection-related reactions, majority at first dose when initiating therapy. Localized reactions that were recurrent and/or delayed were observed. Severe localized reactions and cases leading to dose discontinuation or interruption occurred. LEQEMBI (lecanemab-irmb) is available:

Intravenous infusion: 100 mg/mL Subcutaneous injection: 200 mg/mL Please see full Prescribing Information for LEQEMBI, including Boxed WARNING.

Click here to access the LEQEMBI digital library with assets available for download.

MEDIA CONTACTS

Eisai Co., Ltd.

Public Relations Department

TEL: +81 (0)3-3817-5120 

Biogen Inc.

Madeleine Shin

+1-781-464-3260

[email protected]  

Eisai Europe, Ltd.

EMEA Communications Department

+44 (0) 7760 619251

[email protected]

Eisai Inc. (U.S.)

Julie Edelman

+1-862-213-5915

[email protected] 

INVESTOR CONTACTS

Eisai Co., Ltd.

Investor Relations Department

TEL: +81 (0) 3-3817-5122

Biogen Inc.

Tim Power

+ 1-781-464-2442

[email protected]

Notes to Editors

About lecanemab (generic name, brand name: LEQEMBI®)
Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. It is a humanized immunoglobulin gamma (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ).Lecanemab has been approved in 53 countries and regions including Japan, the U.S., China, Europe, South Korea, Taiwan, and Saudi Arabia, and is under regulatory review in 6 countries. Following the initial phase with treatment every two weeks for 18 months, intravenous (IV) maintenance dosing with treatment every four weeks is approved in 8 countries including the U.S., China, the UK, and others, and applications have been filed in 12 countries and regions. The U.S. FDA approved Eisai's Biologics License Application (BLA) for subcutaneous maintenance dosing with LEQEMBI IQLIK in August 2025. For subcutaneous initiation treatment (500 mg), approval was obtained in the United States in July 2026, and applications are under review in four countries, including Japan and China. In China, the application has been granted Priority Review designation. Since December 2025, lecanemab (IV) has been included in the "Commercial Insurance Innovative Drug List," recently introduced by the National Healthcare Security Administration (NHSA) of China.

LEQEMBI's approvals in these countries were based on Phase 3 data from Eisai's global placebo-controlled, double-blind, parallel-group, randomized 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). Clarity AD evaluated lecanemab 10 mg/kg bi-weekly IV treatment of early Alzheimer's disease, which involved 1,795 patients (treatment group: 898, placebo group: 897). 95% of patients who completed the core study (18 months) chose to continue in the long-term extension study (LTE), with 478 patients still receiving treatment for four years. In the Clarity AD core clinical study, data showed LEQEMBI IV significantly slowed disease progression at 18 months (27% vs placebo), and the mean change from baseline between the lecanemab treated group and the placebo group after 18 months was -0.45 (P=0.00005) on the primary endpoint of CDR-SB global cognitive and functional scale.

To provide context, a change from 0.5 to 1 on the Clinical Dementia Rating (CDR) score domains of Memory, Community Affairs and Home/Hobbies reflects a shift from mild impairment to loss of independence. This can affect a person's ability to be left alone safely, recall recent events, participate in daily activities, manage household tasks, and engage in hobbies and intellectual interests.

LEQEMBI also rapidly reduced plaque as early as three months (−59.1 CL difference vs placebo in amyloid level at 18 months; P<0.00001).* Additionally, LEQEMBI continued to show benefit over a four-year LTE treatment period; in a subgroup analysis, 81 percent of LEQEMBI patients who stayed on treatment remained in the early AD stages at four years.**

Over three years of treatment, including both the core study and the LTE, data showed lecanemab demonstrated a reduction in cognitive decline—measured by CDR-SB—of 1.01 points compared to the expected decline observed in the Alzheimer's Disease Neuroimaging Initiative (ADNI)** cohort. This benefit grew more pronounced after four years, with a reduction of 1.75 points. Similarly, when benchmarked against the expected decline in the BioFINDER cohort, lecanemab showed a reduction of 1.40 points at three years and an even greater reduction of 2.17 points at the four-year mark. In Clarity AD, 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.

*The Centiloid scale is used for amyloid PET, where 0 CL is anchored as the average amyloid in young people without amyloid plaques, and 100 is anchored as the average amyloid level in moderate AD.  The baseline centiloid level in CLARITY AD was approximately 78 CL. Plaque negativity is defined as conversion to amyloid PET negative (<30 centiloid, or CL).

**Prespecified subgroup analysis of reduced risk of progression: Progression was defined as CDR-SB score progressing to moderate or severe dementia (≥9.5), based on Kaplan-Meier plots.

About Protofibrils
Protofibrils are thought to be the most toxic Aβ species that contribute to brain damage in AD and play a major role in the cognitive decline of this progressive and devastating disease. Protofibrils can cause neuronal and synaptic damage in the brain, which can subsequently adversely affect cognitive function through multiple mechanisms.2 The mechanism by which this occurs has been reported not only by increasing the formation of insoluble Aβ plaques, but also by directly damaging signaling between neurons and other cells. It is believed that reducing protofibrils may reduce neuronal damage and cognitive impairment, potentially preventing the progression of AD.3 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 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.

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.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 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 including for lecanemab-irmb (LEQEMBI IQLIK); 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," "assume," "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. These forward-looking statements are based on management's current beliefs and assumptions and on information currently available to management. Given their nature, we cannot assure that any outcome expressed in these forward-looking statements will be realized in whole or in part. We caution that these statements are subject to risks and uncertainties, many of which are outside of our control and could cause future events or results to be materially different from those stated or implied in this document, including, among others, uncertainty of long-term success in developing, licensing, or acquiring other product candidates or additional indications for existing products; expectations, plans and prospects relating to product approvals, approvals of additional indications for our existing products, sales, pricing, growth, reimbursement and launch of our marketed and pipeline products; our ability to effectively implement our corporate strategy; the successful execution of our strategic and growth initiatives, including acquisitions; the risk that positive results in a clinical trial may not be replicated in subsequent or confirmatory trials or success in early stage clinical trials may not be predictive of results in later stage or large scale clinical trials or trials in other potential indications; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; the occurrence of adverse safety events, restrictions on use with our products, or product liability claims; and any other risks and uncertainties that are described in other reports we have filed with the U.S. Securities and Exchange Commission.

These statements speak only as of the date of this press release and are based on information and estimates available to us at this time. Should known or unknown risks or uncertainties materialize or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. Investors are cautioned not to put undue reliance on forward-looking statements. A further list and description of risks, uncertainties and other matters can be found in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and in our subsequent reports on Form 10-Q and Form 10-K, in each case including in the sections thereof captioned "Note Regarding Forward-Looking Statements" and "Item 1A. Risk Factors," and in our subsequent reports on Form 8-K. Except as required by law, we do not undertake any obligation to publicly update any forward-looking statements whether as a result of any new information, future events, changed circumstances or otherwise.

Digital Media Disclosure
From time to time, we have used, or expect in the future to use, our investor relations website (investors.biogen.com), the Biogen LinkedIn account (linkedin.com/company/biogen-) and the Biogen X account (https://x.com/biogen) as a means of disclosing information to the public in a broad, non-exclusionary manner, including for purposes of the SEC's Regulation Fair Disclosure (Reg FD). Accordingly, investors should monitor our investor relations website and these social media channels in addition to our press releases, SEC filings, public conference calls and websites, as the information posted on them could be material to investors.

References

National Institute on Aging (NIA), National Institutes of Health. What Is Mild Cognitive Impairment? Available at: https://www.nia.nih.gov/health/memory-loss-and-forgetfulness/what-mild-cognitive-impairment. Accessed July 22, 2026. 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. SOURCE Eisai Inc.

Key Takeaways Biogen beat Q2 earnings and revenue estimates as growth drugs lifted sales.BIIB raised 2026 revenue and adjusted EPS guidance on stronger growth product performance.Biogen faced weaker MS and biosimilar sales while higher R&D and acquisition costs weighed on earnings. Biogen (BIIB - Free Report) reported second-quarter 2026 adjusted earnings per share (EPS) of $3.60, which significantly beat the Zacks Consensus Estimate of $3.04 per share. Earnings declined 34% year over year due to deal-related charges and increased R&D costs. In the second quarter, Biogen recorded IPR&D, upfront and milestone expenses of approximately $164 million.

Total revenues during the quarter came in at $2.74 billion, up 3% year over year on a reported basis and 2% on a constant-currency basis. Revenues beat the Zacks Consensus Estimate of $2.50 billion.

Lower sales of key multiple sclerosis drugs were offset by higher revenues from new drugs, Skyclarys, Qalsody and Zurzuvae and contributions from the newly acquired drugs, Empaveli and Syfovre, from the Apellis acquisition that closed in May 2026. Spinraza’s sales also improved in the second quarter.

BIIB’s Q2 Revenue BreakdownProduct revenues increased 2% year over year to $1.92 billion. Revenues from anti-CD20 therapeutic programs grew 10% to $513.5 million, driven by royalties on Ocrevus sales and Biogen’s share of profits from Roche’s (RHHBY - Free Report) Rituxan, Gazyva and Lunsumio.

Contract manufacturing, royalty and other revenues declined 1% to $242.4 million. Alzheimer’s collaboration revenues advanced 16% to $63.7 million.

Alzheimer’s collaboration revenues include Biogen’s 50% share of net product revenues and cost of sales (including royalties) from Alzheimer’s disease (AD) drug Leqembi (lecanemab), which has been developed in collaboration with Eisai.

Eisai recorded nearly $184 million in global revenues from Leqembi sales in the second quarter, up 15% year over year and around 10% sequentially, driven by demand growth globally. The drug’s U.S. sales were $97 million.

Biogen's Growth Drugs Gain GroundRare disease revenues rose 11% to $601.7 million.

Spinraza sales increased 2% to $401.9 million as demand and stocking for the high-dose regimen offset unfavorable shipment timing in some international markets. The figure beat the Zacks Consensus Estimate of $379 million.

A higher dose regimen of Spinraza, which reduces the dosing frequency, was recently approved in the United States, Japan and the EU. The high-dose Spinraza improves Biogen’s competitiveness in a highly competitive area. Biogen said that conversion to the high-dose regimen has been better than expected.

Rare disease drug Skyclarys revenues surged 29% to $167.9 million on higher global demand. Skyclarys’ revenues beat the Zacks Consensus Estimate of $155 million.

Qalsody sales increased 59.5% year over year to $31.9 million, driven by demand growth.

Zurzuvae generated $70.8 million, up 53% year over year and 28% sequentially, reflecting demand growth.

Biogen has a collaboration with Supernus Pharmaceuticals (SUPN - Free Report) for Zurzuvae. Biogen and Supernus Pharmaceuticals equally share profits and losses for the commercialization of Zurzuvae in the United States. In outside U.S. markets, Biogen records product sales (excluding Japan, Taiwan and South Korea) and pays royalties to Supernus.

Biosimilar revenues fell 15.9% to $152.8 million, reflecting lower sales of Benepali, Imraldi and Flixabi.

Syfovre and Empaveli contributed $97.4 million and $30.4 million, respectively, to Biogen’s reported revenues in the second quarter.

BIIB's Legacy MS Portfolio Remains Under PressureMultiple sclerosis product revenues declined 13% year over year to $963.3 million due to generic competition for Tecfidera globally and Tysabri in Europe and rising competitive pressure in the MS market.

Vumerity revenues fell 7.4% to $196.5 million due mainly to inventory dynamics. This metric missed the Zacks Consensus Estimate of $205 million.

Tecfidera sales plunged 53% to $90.9 million due to generic erosion globally. The drug’s sales also missed the Zacks Consensus Estimate of $103 million.

Tysabri revenues slipped 0.8% year over year to $450.8 million. The drug’s sales beat the Zacks Consensus Estimate of $375 million.

Combined Avonex and Plegridy sales declined 8.8% to $225.1 million.

Biogen's Operating Costs RiseAdjusted research and development expenses increased 24% to $489.5 million. The increase reflected higher clinical-trial spending on felzartamab, salanersen and litifilimab, the inclusion of Apellis operating costs and lower research funding from Royalty Pharma.

Adjusted selling, general and administrative expenses rose 17% to $679.6 million. The increase was driven by Apellis’ commercial and management operations and higher spending to support product launches.

BIIB Ups 2026 Revenue and EPS OutlookBiogen raised its revenue guidance for the year due to expected higher revenues from growth products. Biogen now expects 2026 revenues to increase by a mid-single-digit percentage from 2025. This is in contrast to the company’s earlier expectation of a mid-single-digit constant-currency decline.

The company raised its underlying adjusted earnings guidance to a range of $15.85-$16.85 per share from the prior expectation of $15.25 to $16.25 per share.

Combined adjusted R&D and SG&A costs are expected to be between $2.65 billion and $2.70 billion for the second half of 2026.

Other Key Announcements in Q2 ReleaseBiogen announced that BIIB091 achieved proof of concept in a phase II study for relapsing-remitting multiple sclerosis. The company will evaluate the next development steps for the asset.

BIIB also exercised its option and in-licensed worldwide rights from partner Ionis (IONS - Free Report) to develop and commercialize BIIB147, a phase I-ready antisense therapy targeting stathmin 2 pre-mRNA in broad amyotrophic lateral sclerosis. Biogen paid Ionis a $15 million one-time license fee.

Our Take on BIIB’s ResultsBiogen delivered a strong second-quarter performance, beating estimates for both earnings and revenues. Revenues from Biogen’s growth products (Empaveli, Qalsody, Skyclarys, Spinraza, Syfovre, Vumerity, Zurzuvae plus Alzheimer’s revenues from the Leqembi collaboration) rose 24% year over year and surpassed the legacy multiple sclerosis portfolio.

The company also raised its sales and earnings guidance due to an improved underlying business outlook. Shares rose 1.5% in pre-market trading, backed by the better-than-expected results and guidance raise.

So far this year, the stock has risen 16.9% compared with the industry’s 4.5% growth.

Image Source: Zacks Investment Research

Biogen has also strengthened its mid-to-late-stage neurology and immunology pipeline lately with M&A deals. Biogen expects five registrational readouts from its late-stage pipeline over the next four quarters.

However, the company continues to face pressure from declining multiple sclerosis and biosimilar sales, while higher research, commercial and acquisition-related costs weigh on earnings. Biogen’s near-term profitability remains affected by acquired in-process research and development charges and dilution from the Apellis transaction.

BIIB’s Zacks RankBiogen currently carries a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

Key Takeaways Biogen's new launches may help offset weaker MS franchise sales in second-quarter results due July 29.BIIB may see growth from Skyclarys, Zurzuvae and Alzheimer's collaboration revenues in Q2.Biogen will record acquisition-related IPR&D charges as investors watch Apellis portfolio sales. We expect Biogen (BIIB - Free Report) to beat expectations when it reports second-quarter 2026 results on July 29, before market opens. In the last reported quarter, the company's earnings beat expectations by 21.02%. The Zacks Consensus Estimate for second-quarter sales and earnings is pegged at $2.47 billion and 79 cents per share, respectively.

Factors to Consider for BiogenIn the second quarter, lower sales of Biogen’s multiple sclerosis (“MS”) drugs, excluding Vumerity, are likely to have been offset by sequential revenue growth from new products.

Sales of Biogen’s MS drugs like Tecfidera and Tysabri are likely to have declined due to generic competition for Tecfidera globally, biosimilar competition for Tysabri in Europe and rising competitive pressure in the MS market.

Biogen saw an increased impact of Tecfidera generics in Europe in the last two quarters, with the trend expected to continue in the second quarter.

The Zacks Consensus Estimate for second-quarter sales of Tecfidera is pegged at $103.0 million. The Zacks Consensus Estimate for Tysabri is $375.0 million.

Sales of another MS drug, Vumerity, are expected to have risen due to strong demand in the United States. The Zacks Consensus Estimate for Vumerity is $205.0 million.

Sales of Biogen’s spinal muscular atrophy drug, Spinraza, are likely to have declined due to lower demand in the U.S. market. The Zacks Consensus Estimate for Spinraza is $379.0 million.

The performance of Biogen’s newly launched drug Skyclarys for Friedreich’s ataxia is likely to have continued to improve sequentially, backed by demand growth in outside U.S. markets. The Zacks Consensus Estimate for Skyclarys sales is $155.0 million.

Sales of another new drug, Zurzuvae, are likely to have benefited from strong demand trends.

Biogen has a collaboration with Supernus Pharmaceuticals (SUPN - Free Report) for Zurzuvae. Biogen and Supernus Pharmaceuticals equally share profits and losses for the commercialization of Zurzuvae in the United States. In outside U.S. markets, Biogen records product sales (excluding Japan, Taiwan and South Korea) and pays royalties to Supernus.

Alzheimer’s collaboration revenues are expected to have risen in the quarter. Alzheimer’s collaboration revenues include Biogen’s 50% share of net product revenues and cost of sales (including royalties) from Alzheimer’s drug Leqembi (lecanemab), which has been developed in collaboration with Eisai.

Leqembi sales have been improving sequentially over the past few quarters, driven by demand growth globally. The positive trend is expected to have continued in the second quarter. Eisai records Leqembi sales.

In May, Biogen closed its acquisition of Apellis Pharmaceuticals, adding the commercialized medicines Empaveli and Syfovre for immune-mediated retinal disease and nephrology to its commercial portfolio. Investors will look for sales numbers of these newly added drugs. In June, Biogen announced a definitive agreement to acquire RayThera for $1 billion to strengthen its immunology pipeline.

In the second quarter, Biogen will record IPR&D charges related to the Apellis acquisition and the acquisition of exclusive rights to felzartamab in China from TJ Biopharma, which will hurt its EPS.

In the second quarter, Biogen expects core operating expenses to be roughly consistent with the first quarter.

BIIB’s Earnings Surprise HistoryThe company’s earnings beat estimates in each of the last four quarters. The company has a four-quarter earnings surprise of 26.87%, on average.

Biogen’s stock has risen 14.0% so far this year compared with an increase of 2.2% for the industry.

Image Source: Zacks Investment Research

What Our Model Says for BIIBOur proven model predicts an earnings beat for Biogen this time around. The combination of a positive Earnings ESP and a Zacks Rank #1 (Strong Buy), 2 (Buy) or 3 (Hold) increases the odds of an earnings beat, which is the case here.

Earnings ESP: Biogen’s Earnings ESP is +282.03%. The Zacks Consensus Estimate is pegged at 79 cents per share, while the Most Accurate Estimate is pegged higher at $3.02 per share. You can uncover the best stocks to buy or sell before they’re reported with our  Earnings ESP Filter.

Zacks Rank: Biogen has a Zacks Rank #3.

Other Stocks to ConsiderHere are two drug/biotech stocks that also have the right combination of elements to beat on earnings this time around:

Regeneron Pharmaceuticals (REGN - Free Report) has an Earnings ESP of +1.22% and a Zacks Rank #3. You can see the complete list of today’s Zacks #1 Rank stocks here.

Regeneron stock has declined 15.3% so far this year. REGN beat estimates in each of the last four quarters. The company has a four-quarter earnings surprise of 26.33%, on average. Regeneron is scheduled to report second-quarter results on July 30.

Pfizer (PFE - Free Report) has an Earnings ESP of +2.07% and a Zacks Rank #3 at present.

Shares of Pfizer have risen 3.8% so far this year. Pfizer beat earnings estimates in each of the last four reported quarters, delivering an average earnings surprise of 21.93%. Pfizer is scheduled to report second-quarter results on Aug. 4.

Real-World Findings Support Long-Term Benefits of Continuous Treatment with LEQEMBI and Provide Important Insights into Treatment Experience Outside of a Clinical Trial Setting

, /PRNewswire/ -- Eisai Co., Ltd. and Biogen Inc. (Nasdaq: BIIB) announced today that results from the real-world Lecanemab in Early Alzheimer's Disease (LEADER) Study show that nearly 83% of early Alzheimer's disease (AD) patients enrolled in the study remained stable (75.9%) or improved (6.6%) while receiving LEQEMBI® therapy over an average of 17 months. The results were consistent across sex, race, ethnicity and APOE genotype. The data was presented during the "Developing Topics Session #3-33-DEV-A: Lecanemab Three Years Post-Approval: A Comprehensive Multicenter, Real-World, Retrospective Study (LEADER) in Diverse US Clinical Settings" at the Alzheimer's Association International Conference® (AAIC®) 2026 in London and online.

AD is a chronic, progressive disease that requires ongoing treatment. LEQEMBI targets the underlying pathology of the disease and works in two ways throughout treatment - by removing insoluble (plaque) and soluble amyloid beta (protofibrils), helping to slow cognitive decline and loss of daily functioning. Data show continued treatment with LEQEMBI may be able to help keep patients in early AD for longer. Early AD includes mild cognitive impairment (MCI) due to AD and mild AD dementia.

LEADER Study Design
The three-year LEADER Study is a multicenter, retrospective real-world study designed to examine LEQEMBI utilization, treatment persistence, transition to maintenance therapy, safety, cognitive and functional assessments, and healthcare professional (HCP) implementation learnings in diverse U.S. clinical settings for patients with early Alzheimer's disease (AD). The study integrated deidentified chart and electronic medical record (EMR) data from 13 U.S. sites, HCP surveys and HCP interviews. This interim analysis included 432 patients with early AD who received at least seven LEQEMBI infusions as of May 2026.

Patient Characteristics at Baseline

Mean age: 74 years Female Patients: 55.8%  Disease Stage at Baseline

Mild cognitive impairment (MCI) due to AD: 63.9% Mild AD dementia: 36.1%. Treatment

The mean duration of LEQEMBI treatment was 520 days. The mean number of LEQEMBI doses was 26. Change in disease stage was defined as: Stable: Patient remaining in the same disease stage (MCI due to AD or mild AD dementia) from baseline throughout the course of LEQEMBI treatment. Improvement: Patient transitioning from mild AD dementia at baseline to MCI due to AD over the course of LEQEMBI treatment. Progression: Patient advancing from MCI at baseline to mild/moderate AD dementia or from mild AD dementia at baseline to moderate AD dementia throughout the course of LEQEMBI treatment. LEADER Study Key Findings
Real-World Evidence Shows Long-Term Benefit with Continuous LEQEMBI Treatment Across Sex, Race, Ethnicity and APOE Genotype

Overall Study Population Findings

Of the 432 participants enrolled in the LEADER Study, disease stage could be evaluated in 427. Among these patients with early Alzheimer's disease, 82.5% remained stable or improved while receiving LEQEMBI, with consistent results across sex, race, ethnicity, and APOE genotype groups. 75.9% remained stable compared with baseline, meaning they remained in the same disease stage throughout treatment. 6.6% improved from baseline, moving from mild AD dementia to MCI due to AD. Nearly 87% of patients chose to remain on LEQEMBI treatment. In analyses by APOE ε4 status, clinician-evaluated stable or improved disease stage was observed in: 81.7% of APOE ε4 heterozygotes (stable: 73.8%; improved: 7.9%) 81.0% of APOE ε4 homozygotes (stable: 75.9%; improved: 5.2%). Maintenance Dosing Population Findings

Of the 432 participants in the LEADER Study, 155 transitioned to once-every-four-weeks intravenous (IV) maintenance treatment, and 14 transitioned to once-weekly subcutaneous (SC) maintenance treatment. Among the 155 participants who transitioned to IV maintenance therapy, nearly 81% remained stable (72.3%) or improved (8.4%). Of the 14 patients who transitioned to SC maintenance treatment, 12 (85.7%) maintained their disease stage. Real-World Safety Consistent with U.S. FDA-Approved Label

Overall safety observations in this real-world study were consistent with the U.S. FDA-approved label.

ARIA (amyloid-related imaging abnormalities)* was observed in 12.3% of patients overall; ARIA-E was observed in 6.3% and ARIA-H in 7.9% and isolated ARIA-H in 6.0%. Most ARIA cases were asymptomatic and mild in radiographic severity. No new ARIA-E events, macrohemorrhages or intracerebral hemorrhages greater than 1 cm were reported during once-every-four-weeks IV maintenance therapy.   APOE ε4 status safety observations were consistent with the overall cohort and the U.S. FDA-approved label.

ARIA-E was observed in 5.3% of APOE ε4 noncarriers, 6.1% of APOE ε4 heterozygotes and 10.3% of APOE ε4 homozygotes. ARIA-H was observed in 12.1%, 4.8% and 12.1%, respectively. In APOE ε4 homozygotes, no severe ARIA was reported, and all graded ARIA cases were mild to moderate in radiographic severity. Antithrombotic therapy, including anticoagulants or antiplatelet medications, was used by 106 patients, representing 24.5% of the study population.

Of these, 11 patients were receiving an anticoagulant, either alone or with an antiplatelet medication, and 95 patients were receiving antiplatelet therapy only. Among patients receiving antithrombotic therapy, the incidence of ARIA was not meaningfully different from that observed in patients not receiving antithrombotic therapy. * ARIA refers to amyloid-related imaging abnormalities that can be observed with anti-amyloid beta antibody treatment and includes ARIA-E, which involves edema/effusion, and ARIA-H, which involves hemosiderin deposition, including cerebral microhemorrhage, cerebral macrohemorrhage and superficial siderosis, as observed on brain magnetic resonance imaging (MRI).

Eisai serves as the lead for lecanemab's development and regulatory submissions globally with Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

MEDIA CONTACTS

Eisai Co., Ltd.

Public Relations Department

TEL: +81 (0)3-3817-5120

Eisai Europe, Ltd.

EMEA Communications Department

+44 (0)7760 619251

[email protected]

Eisai Inc. (U.S.)

Julie Edelman

+1-862-213-5915

[email protected] 

Biogen Inc.

Madeleine Shin

+1-781-464-3260

[email protected] 

INVESTOR CONTACTS

Eisai Co., Ltd.

Investor Relations Department

TEL: +81 (0) 3-3817-5122

Biogen Inc.

Tim Power

+1-781-464-2442

[email protected]

Notes to Editors

About lecanemab (generic name, brand name: LEQEMBI®)
Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. It is a humanized immunoglobulin gamma (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ).

Lecanemab has been approved in 53 countries and regions including Japan, the United States, China, Europe, South Korea, Taiwan, and Saudi Arabia, and is under regulatory review in 6 countries. Following the initial phase with treatment every two weeks for 18 months, intravenous (IV) maintenance dosing with treatment every four weeks was approved in 8 countries including the U.S., China, the UK, and others, and applications have been filed in 12 countries and regions. The U.S. FDA approved LEQEMBI IQLIK, the subcutaneous autoinjector formulation of lecanemab, for use as maintenance treatment in August 2025 and as initiation treatment on July 13, 2026. In November 2025, an application for a subcutaneous injectable formulation in Japan was submitted. In January 2026, the Biologics License Application (BLA) for the subcutaneous formulation was accepted in China. Since December 2025, lecanemab (IV) has been included in the "Commercial Insurance Innovative Drug List", recently introduced by the National Healthcare Security Administration (NHSA) of China.

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 Protofibrils
Protofibrils are thought to be the most toxic Aβ species that contribute to brain damage in AD and play a major role in the cognitive decline of this progressive and devastating disease. Protofibrils can cause neuronal and synaptic damage in the brain, which can subsequently adversely affect cognitive function through multiple mechanisms.1 The mechanism by which this occurs has been reported not only by increasing the formation of insoluble Aβ plaques, but also by directly damaging signaling between neurons and other cells. It is believed that reducing protofibrils may reduce neuronal damage and cognitive impairment, potentially preventing the progression of AD.2

Limitations of Real-World Studies
Retrospective real-world studies can be valuable in providing additional information to complement clinical trial data; however, there are potential limitations to consider, including: potential for biases, data completeness and consistency, lack of a control group, interpretation of data due to lack of placebo-controlled arms, and confounding variables, and data inconsistency. Data inconsistency may be mitigated by providing site access to standardized electronic case-report forms.

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 LEQEMBI 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 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.

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 www.biogen.com. 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 including for lecanemab-irmb (LEQEMBI IQLIK); 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," "assume," "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.

These forward-looking statements are based on management's current beliefs and assumptions and on information currently available to management. Given their nature, we cannot assure that any outcome expressed in these forward-looking statements will be realized in whole or in part. We caution that these statements are subject to risks and uncertainties, many of which are outside of our control and could cause future events or results to be materially different from those stated or implied in this document, including, among others, uncertainty of long-term success in developing, licensing, or acquiring other product candidates or additional indications for existing products; expectations, plans and prospects relating to product approvals, approvals of additional indications for our existing products, sales, pricing, growth, reimbursement and launch of our marketed and pipeline products; our ability to effectively implement our corporate strategy; the successful execution of our strategic and growth initiatives, including acquisitions; the risk that positive results in a clinical trial may not be replicated in subsequent or confirmatory trials or success in early stage clinical trials may not be predictive of results in later stage or large scale clinical trials or trials in other potential indications; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; the occurrence of adverse safety events, restrictions on use with our products, or product liability claims; and any other risks and uncertainties that are described in other reports we have filed with the U.S. Securities and Exchange Commission, which are available on the SEC's website at www.sec.gov.

These statements speak only as of the date of this press release and are based on information and estimates available to us at this time. Should known or unknown risks or uncertainties materialize or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. Investors are cautioned not to put undue reliance on forward-looking statements. A further list and description of risks, uncertainties and other matters can be found in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 and in our subsequent reports on Form 10-Q, Except as required by law, we do not undertake any obligation to publicly update any forward-looking statements whether as a result of any new information, future events, changed circumstances or otherwise.

Digital Media Disclosure
From time to time, we have used, or expect in the future to use, our investor relations website (investors.biogen.com), the Biogen LinkedIn account (linkedin.com/company/biogen-) and the Biogen X account (https://x.com/biogen) as a means of disclosing information to the public in a broad, non-exclusionary manner, including for purposes of the SEC's Regulation Fair Disclosure (Reg FD). Accordingly, investors should monitor our investor relations website and these social media channels in addition to our press releases, SEC filings, public conference calls and websites, as the information posted on them could be material to investors.

References

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. SOURCE Eisai Inc.

Store

SubscribeSign In

My Subscriptions

Founder's ClubSwingTraderLeaderboardMarketSurgeeIBDIBD DigitalIBD LiveCustomer Center

My Stock Lists

Email Preferences

Help & Support

Sign Out

Search stocks or keywords

Sections

My IBD

MARKET TREND

STOCK LISTS

STOCK RESEARCH

NEWSECONOMY

VIDEOS & PODCASTS

HOW TO INVESTEDUCATIONAL RESOURCESStoreMy Products

Founder's ClubSwingTraderLeaderboardMarketSurgeeIBDIBD DigitalIBD Live

Recently Searched

Valero, Marathon, Other Oil Firms Defy Weak Market, Hit Record Highs, Lead 21 Onto Best Stock Lists

Stock Market, Treasuries Sink As Oil Soars On New U.S. Blockade; This Asset Also Dives

Jim Roppel: How To Find The Next Golden Opportunities As Bull Market Leaders Take A Breather Biogen (BIIB) and Ionis Pharmaceuticals (IONS) said Tuesday their tau-targeting Alzheimer's treatment slowed cognitive decline by 26% over the course of 18 months. The results nearly match Biogen and Eisai's approved drug, Leqembi, which slowed cognitive decline by 27% over its 18-month, final-phase study. Eli Lilly's (LLY) rival drug, Kisunla, led to a 35% slower decline on the same scale,…

Copyright ©2026 Investor's Business Daily, LLC. All rights reserved. 87990cbe856818d5eddac44c7b1cdeb8

Biogen (BIIB +3.04%) built itself into a biotech giant thanks to its portfolio of multiple sclerosis (MS) drugs -- but in biotech and pharma, revenue growth depends on the life of a patent. Once a company loses exclusivity, generics or biosimilars enter the market, and the leader's drug sales decline. This is the challenge Biogen has faced in recent years, as MS blockbusters faced growing competition.

But the biotech giant put into place a recovery and growth plan, shifting many costs out of the MS franchise and into areas that represented growth potential. Biogen also made strategic acquisitions, announcing its intention to buy Apellis Pharmaceuticals, an immunology and rare diseases drug company, in March and closing the deal in May.

And just recently, Biogen announced another purchase. This time, the biotech is paying $1 billion for a company that won't say what it makes. Here's why this actually is good news for Biogen investors.

Image source: Getty Images.

Biogen's multiple sclerosis business Let's start with a quick update on Biogen. As mentioned, the biotech company was once known as an MS giant, and it still sells a number of important MS drugs, such as Tecfidera and Tysabri. But loss of exclusivity made a significant dent in revenue, with Tecfidera's peak sales of $4.4 billion in 2019 dropping to $1.4 billion in 2022. In the latest fiscal year, all of Biogen's MS drugs, together, delivered $4 billion in revenue, further highlighting this decline.

In the recent quarter, chief executive officer Christopher Viehbacher said that after four years of declining earnings in 2023, the turnaround began -- and Biogen finally has been able to "stabilize the business." The shift of focus to growth products helped these drugs deliver a 12% increase in sales to $850 million in the first quarter. These are key neurology drugs such as Leqembi for Alzheimer's disease, Skyclarys for Friedreich ataxia, and postpartum depression drug Zurzuvae. They each brought in double- or triple-digit sales growth.

And though Biogen hasn't returned to its peak earnings levels, it looks like a rebound is taking shape, and this may lead to fresh growth.

BIIB Net Income (Quarterly) data by YCharts

Acquisitions to support growth Biogen, of course, has a solid internal pipeline, but the company, aiming to make immunology another key area, has used acquisitions to gain strength here. As mentioned, Biogen bought Apellis, gaining access to two commercialized drugs in this specialty area: Empaveli for three indications, including two rare kidney diseases, and Syfovre for an immune-mediated retinal disease. These drugs together delivered sales of $689 million last year.

Now, let's consider the company's very latest move, and that's to acquire RayThera for as much as $1 billion, including an upfront payment and potential milestone payments. RayThera's website doesn't offer much detail about its candidates -- we don't know the exact diseases they target. What we do know, from the acquisition press release, is that the portfolio "includes multiple anti-inflammatory assets that could potentially treat immune-mediated conditions across a range of indications." And the company's lead candidate is on track to enter a phase 1 trial in the third quarter.

Today's Change

(

3.04

%) $

6.38

Current Price

$

216.12

Why is all of this good news for shareholders? The above statement suggests that RayThera's candidates aren't just targeting a disease or two. Instead, they might have the ability to treat a significant number of immune-mediated illnesses, and that could equal enormous revenue potential down the road. The global immunology market is massive, totaling more than $112 billion last year, according to Fortune Business Insights. Since Biogen is seeking to build out its immunology business, this addition could be a very wise move.

Of course, it's important to keep in mind that a lead candidate that's about to enter phase 1 doesn't result in revenue right away. The RayThera assets, even if successful through clinical trials, will take years to reach the commercialization stage. But that's OK. A biotech company must have a deep pipeline to generate the winning drugs of tomorrow. So acquiring Apellis to gain access to already commercialized drugs and buying RayThera for its pipeline were great strategic moves.

Biogen, after a few tough years, seems to be on the right track toward building out new growth businesses that may deliver over time -- and this is a solid reason to buy and hold the shares.

Key Takeaways Biogen's newer drugs are growing but remain insufficient to offset declining MS franchise sales.Leqembi's subcutaneous autoinjector and blood-based diagnostics may support growth from 2027 onward.Biogen's growth products generated $851 million in Q1 sales, up 12% year over year. Biogen (BIIB - Free Report) is in the midst of a major portfolio transition. The company is seeing declining sales of its key multiple sclerosis (“MS”) drugs like Tecfidera and Tysabri and spinal muscular atrophy (SMA) treatment, Spinraza, due to generic erosion, increasing competition from newer therapies and pricing headwinds.

To combat the pressure on key drugs, Biogen has been aggressively building a new growth engine around recently launched products, Eisai-partnered Leqembi for Alzheimer’s disease, Skyclarys for Friedreich’s ataxia, Qalsody for amyotrophic lateral sclerosis (ALS) and Supernus Pharmaceuticals (SUPN - Free Report) -partnered Zurzuvae for depression.

The key question for investors is whether these products can eventually compensate for the erosion of blockbuster drugs like Tecfidera, Tysabri and Spinraza. Let us discuss.

Key Multiple Sclerosis Drugs, Spinraza Face Increased CompetitionBiogen’s MS sales are declining due to generic competition for Tecfidera globally, biosimilar competition for Tysabri in Europe and rising competitive pressure in the MS market.

In 2026, Biogen expects revenues for MS products, excluding Vumerity, to decline by a mid-teen percentage versus 2025 due to increased competitive pressure on the ex-U.S. MS business, particularly accelerating generic competition for Tecfidera in Europe.

Spinraza’s sales are also declining due to lower demand amid increasing competitive pressure from newer SMA treatments, including gene therapies and oral medicines that offer greater convenience. Spinraza faces competition from Novartis’ (NVS - Free Report) gene therapy, Zolgensma, and Roche and PTC Therapeutics’ (PTCT - Free Report) Evrysdi (risdiplam), which comes as either a liquid solution or an oral tablet.

BIIB’s New Drug Contributing to Top-Line GrowthAmid declining demand for MS drugs and Spinraza, Biogen believes its new products, Leqembi, Skyclarys and Zurzuvae have the potential to return the company to revenue growth.

The largest opportunity in Biogen's new portfolio is arguably Leqembi. Leqembi/lecanemab gained approval for early Alzheimer’s disease in the United States in 2023. Though the Leqembi launch was slow, it picked up in 2024 and 2025. Leqembi has also been launched in Japan, China, the EU and some other countries. Leqembi commands over 60% of the anti-amyloid therapy market share in the United States.

A less frequent maintenance intravenous dosing version of Leqembi was approved by the FDA in January 2025. A subcutaneous autoinjector for maintenance dosing called Leqembi Iqlik was launched in October 2025, while a supplemental filing seeking approval of the Leqembi Iqlik subcutaneous autoinjector for initiation dosing has been granted priority review by the FDA, with a decision expected in August. Biogen and Eisai believe that the introduction of blood-based diagnostics (which can help earlier detection of Alzheimer’s) and the subcutaneous autoinjector for maintenance and initiation should drive Leqembi’s growth from 2027 onward.

Other new products, Qalsody, Biogen/Supernus’ Zurzuvae and Skyclarys (added from the 2023 acquisition of Reata Pharmaceuticals) are also seeing strong demand trends in the United States.

Skyclarys is seeing strong demand trends in the United States as well as the EU. Biogen expects Skyclarys’ future growth to come from ex U.S. markets as the launches advance. Zurzuvae’s launch also exceeded the company’s internal expectations, with sales more than doubling in 2025. Skyclarys and Zurzuvae’s sales are expected to continue to rise in 2026.

Biogen’s growth products (Skyclarys, Qalsody, Zurzuvae, Vumerity and Spinraza plus Alzheimer’s revenues from the Leqembi collaboration) generated sales of $851 million in the first quarter, rising 12% year over year.

In April, Biogen closed its acquisition of Apellis Pharmaceuticals, adding the commercialized medicines Empaveli and Syfovre for immune-mediated retinal disease and nephrology to its commercial portfolio. These drugs should also contribute to Biogen’s growth in future quarters.

Can BIIB’s New Drugs Offset Key Drugs’ Erosion?After declining for several years, Biogen’s revenues have somewhat stabilized since 2024 due to contributions from newer products and pipeline progress. However, its newer drugs, Leqembi, Skyclarys, Qalsody and Zurzuvae, are currently insufficient to offset the near-term top-line decline of the MS franchise. Though all these new drugs are showing signs of growth, replacing lost revenues from Tecfidera, Tysabri and Spinraza will likely take time.

BIIB’s Price Performance, Valuation and EstimatesBiogen’s stock has risen 14.8% so far this year compared with an increase of 5.4% for the industry. 

Image Source: Zacks Investment Research

From a valuation standpoint, Biogen is reasonably priced. Going by the price/earnings ratio, the company’s shares currently trade at 13.44 forward earnings, which is lower than 17.72 for the industry. The stock is trading above its five-year mean of 13.17.

Image Source: Zacks Investment Research

The Zacks Consensus Estimate for earnings has declined from $15.04 per share to $13.99 per share for 2026 over the past 60 days. For 2027, the consensus mark for earnings has declined from $16.61 to $16.22 per share over the same time frame.

Image Source: Zacks Investment Research

Biogen has a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.