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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.) TOKYO and CAMBRIDGE, Mass., Aug. 24, 2026 (GLOBE NEWSWIRE) -- 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 (IRR s ) IRRs were observed—LEQEMBI: 26%; placebo: 7%—and most cases with LEQEMBI (75%) occurred with the first infusion. IRRs were mostly mild (69%) or moderate (28%). Symptoms included fever and flu-like symptoms (chills, generalized aches, feeling shaky, and joint pain), nausea, vomiting, hypotension, hypertension, and oxygen desaturation. 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 pro 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 Eisai Europe, Ltd. EMEA Communications Department +44 (0) 7760 619251 Emea-comms@eisai.net Eisai Inc. (U.S.) Julie Edelman +1-862-213-5915 Julie_Edelman@eisai.com Biogen Inc. Madeleine Shin +1-781-464-3260 public.affairs@biogen.com INVESTOR CONTACTS Eisai Co., Ltd. Investor Relations Department TEL: +81 (0) 3-3817-5122 Biogen Inc. Tim Power + 1-781-464-2442 IR@biogen.com Notes to Editors 1. 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; P10%) 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. 2. 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 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. 4. 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. 5. About Eisai Co., Ltd. Eisai's Corporate Concept is "to give first thought to patients and people in the daily living domain, and to increase the benefits that health care provides." Under this Concept (also known as human health care ( hhc ) Concept), we aim to effectively achieve social good in the form of relieving anxiety over health and reducing health disparities. With a global network of R&D facilities, manufacturing sites and marketing subsidiaries, we strive to create and deliver innovative products to target diseases with high unmet medical needs, with a particular focus in our strategic areas of Neurology and Oncology. In addition, we demonstrate our commitment to the elimination of neglected tropical diseases (NTDs), which is a target (3.3) of the United Nations Sustainable Development Goals (SDGs), by working on various activities together with global partners. For more information about Eisai, please visit (for global headquarters: Eisai Co., Ltd.), and connect with us on X , LinkedIn and Facebook . The website and social media channels are intended for audiences outside of the UK and Europe. For audiences based in the UK and Europe, please visit and Eisai EMEA LinkedIn . 6. 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 . 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. 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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 ( ) 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: . 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.

GENGLYCOS is the first gene therapy approval, and fifth FDA approval overall, for the company Approval provides a long-awaited first-ever option to reduce the burden of care associated with GSDIa Ultragenyx received a Priority Review Voucher upon approval Ultragenyx to host conference call on 8/19/26 at 6:00 p.m. Eastern Time NOVATO, Calif., Aug. 19, 2026 (GLOBE NEWSWIRE) -- Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) today announced that the U.S. Food and Drug Administration (FDA) granted accelerated approval for GENGLYCOS™ (pariglasgene brecaparvovec-opnr), also known as DTX401, in adult and pediatric patients eight years and older with glycogen storage disease type Ia (GSDIa). “The approval of GENGLYCOS fulfills our commitment to provide the first therapy that directly targets the root cause of GSDIa. The reduced reliance on cornstarch, experienced by patients in our clinical studies, demonstrates this gene therapy’s ability to establish the normal breakdown of glycogen to produce glucose during fasting or episodes of metabolic stress. This ability to regulate glucose has alleviated the disease burden and has the potential to mitigate the risk of severe or life-threatening hypoglycemia for these patients,” said Eric Crombez, M.D., chief medical officer at Ultragenyx. “As our first gene therapy approval, GENGLYCOS represents an important achievement for our company and the realization of the promise of a powerful new tool to deliver transformative medicines for people living with rare diseases.” GSDIa is an ultra-rare genetic metabolic disorder caused by a deficiency of the enzyme needed to release glucose from the liver to the bloodstream. The deficiency reduces the liver’s ability to control glucose levels and is associated with potentially life-threatening hypoglycemia episodes and other serious complications, requiring rigorous nutritional management that involves a burdensome, around-the-clock regimen of raw cornstarch intake as an oral glucose replacement therapy. Glucose control with cornstarch is crude with large swings in glucose, and patients instead end up spending a large fraction of their day significantly hyperglycemic to avoid hypoglycemic episodes. GSDIa affects 1,500-2,500 patients in the U.S. and 6,000-8,000 worldwide within commercially accessible geographies. “Day-to-day management of GSDIa requires a relentless regimen of raw cornstarch and strict dietary management that can be extraordinarily demanding for patients and families. Even with meticulous adherence to this regimen, patients must be perfect. Any missed cornstarch puts patients at risk of severe hypoglycemia, seizures, and even death,” said David Weinstein, M.D., MMSc, one of the world's leading GSDIa experts. “The approval of GENGLYCOS represents a major step forward for the GSDIa community and reflects almost 30 years of work and scientific progress aimed at improving safety and the quality of life of people living with this disease.” “For families affected by GSDIa, every day revolves around strict schedules, overnight vigilance, and the constant worry that a missed meal or dose of cornstarch could trigger life-threatening hypoglycemia,” said David and Wendy Feldman, co-founders and current Board members at The Children’s Fund for Glycogen Storage Disease Research. “This approval is an incredibly meaningful milestone for a community that has spent decades hoping, advocating, and helping advance the research for new treatment options that could ease the burdens of this disease.” Clinical Program and Post-Marketing Study Requirements Supporting Accelerated Approval of GENGLYCOS The approval of GENGLYCOS is based on positive data from the 48-week randomized, double-blind, placebo-controlled Phase 3 GlucoGene study which treated 46 participants aged eight years and older with DTX401 (1.0 x 10^13 GC/kg dose) or placebo, showing a reduction in the cornstarch requirements in the treated group (p<0.001). There were 44 participants in the modified intention-to-treat (mITT) population providing efficacy data within the Week 48 analysis period following treatment with DTX401 (n=20) or placebo (n=24). At Week 48, eligible participants crossed over and received the alternate treatment. After crossover, participants continued to be followed, with analyses conducted at Week 96 and Week 144. As part of accelerated approval, Ultragenyx has agreed to provide two years of safety and efficacy clinical data from open-label commercial treatment of 50 patients and 20 control patients through enhancement of its existing GSDIa Disease Monitoring Program (DMP). The control group will consist of patients who sought commercial treatment but cannot be treated with GENGLYCOS due to the presence of anti-AAV8 antibodies. The study will provide more data to support the reduction in cornstarch clinical burden, fasting tolerance, and other measures in a post-marketing setting where patients can know their immediate glucose levels, and their cornstarch and diet can be managed more promptly by their physician. The DMP will also evaluate previously treated clinical trial participants as well as these new commercial patients for a total of 10 years. Enabling Access for Eligible Patients Ultragenyx will provide support to help enrolled patients and caregivers navigate access to treatment through its UltraCare ® program, which now includes specially trained UltraCare ® Gene Therapy Guides to help understand insurance coverage, assist in obtaining treatment support, and answer questions about the treatment process. Dedicated in-house UltraCare Gene Therapy Guides are available Monday through Friday from 9 a.m. to 8 p.m. Eastern Time at 888-756-8657. More information is available at . GENGLYCOS will be available through a national network of Qualified Treatment Centers (QTCs) with specialized expertise and training to safely administer gene therapy. GENGLYCOS is manufactured entirely at Ultragenyx’s Gene Therapy Manufacturing Facility (GTMF) in Bedford, Mass., strengthening the Company’s ability to scale production of high-quality gene therapy products and deliver them to patients as efficiently as possible. More information will be available at This approval reflects the work of a remarkable team spanning many years and organizations. Ultragenyx is deeply grateful to the patients, families, and clinical investigators who made our clinical studies possible; Dr. David Weinstein, whose scientific and clinical leadership laid critical groundwork across early research and clinical trials; Dr. Janice Chou for her early work at NIH, and the team from Dimension Therapeutics. Their collective commitment and perseverance have transformed a scientific vision into a new therapeutic option for patients. Investor Conference Call and Webcast Information Ultragenyx will host a conference call today at 6:00 p.m. Eastern Time / 3:00 p.m. Pacific Time to discuss the approval of GENGLYCOS. The live and replayed webcast of the call will be available through the company's website at . INDICATION GENGLYCOS (pariglasgene brecaparvovec-opnr) is indicated to reduce daily cornstarch intake as an adjunct to nutritional management in adult and pediatric patients 8 years of age and older with glycogen storage disease type Ia (GSDIa). This indication is approved under accelerated approval based on reduction in daily cornstarch intake . Continued approval for this indication may be contingent upon verification of clinical benefit in confirmatory trial(s). IMPORTANT SAFETY INFORMATION CONTRAINDICATIONS GENGLYCOS is contraindicated in patients with known severe hepatic fibrosis or cirrhosis. WARNINGS AND PRECAUTIONS Hypersensitivity and Infusion Reactions (IRs) Hypersensitivity reactions including anaphylaxis and IRs have occurred with GENGLYCOS treatment. Severe reactions have been reported. Monitor for signs and symptoms of hypersensitivity and IRs, including urticaria, flushing, hypotension, bronchospasm, dyspnea, chest tightness, nausea, vomiting, headache, abdominal pain, lightheadedness, flu-like symptoms, shivering, rash, and hypertension. Premedicate with acetaminophen and non-sedating antihistamines and administer GENGLYCOS according to recommended infusion rates. Monitor patients during and after completion of GENGLYCOS infusion as clinically indicated. If anaphylaxis or severe IR occurs, pause GENGLYCOS infusion immediately and initiate medical treatment as clinically indicated, monitoring as needed. For mild to moderate IRs, consider slowing or temporarily interrupting the infusion, and administer symptomatic treatment as clinically indicated. The infusion may be restarted at half the prior rate upon resolution of symptoms. Medical support measures, including cardiopulmonary resuscitation equipment and medications for the treatment of anaphylaxis (e.g., epinephrine, antihistamines, corticosteroids), should be available during GENGLYCOS administration. Hepatotoxicity Immune-mediated hepatotoxicity, with elevated alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) levels, has occurred with GENGLYCOS. Avoid use in patients with preexisting hepatic impairment or acute hepatic viral infection. Prior to GENGLYCOS infusion, evaluate liver-related medical history and assess liver function by clinical examination and laboratory testing. Advise patients to immediately report signs and symptoms of hepatotoxicity, including fatigue, jaundice, dark urine, nausea, vomiting, and right upper quadrant pain. Administer corticosteroids to all patients after GENGLYCOS infusion in order to mitigate hepatic reactions. Elevated transaminases may require adjustment of the corticosteroid treatment regimen, including increased dose or prolongation of the corticosteroid taper. Monitor transaminase levels for the first 6 months after GENGLYCOS administration. Continue to monitor transaminases in all patients who develop transaminase elevations, until transaminases return to baseline or as clinically indicated. Adrenal Insufficiency Adrenal insufficiency, including serious events, has been reported in patients receiving GENGLYCOS during corticosteroid use and tapering. Signs and symptoms of adrenal insufficiency include fatigue, weakness, anorexia, nausea, vomiting, hypotension, hyponatremia, and hypoglycemia. Adrenal crisis may present as severe hypotension, acute abdominal pain, or loss of consciousness. Monitor patients for signs and symptoms of adrenal insufficiency and adrenal crisis after GENGLYCOS administration during and after corticosteroid therapy and tapering. Taper corticosteroid therapy gradually. Do not abruptly discontinue corticosteroid therapy. AAV Vector Integration and Risk of Tumorigenicity There is a theoretical risk of tumorigenicity due to integration of AAV vector DNA into the genome. GENGLYCOS is composed of a recombinant, non-replicating AAV8 vector whose DNA persists largely in episomal form. Random integration of recombinant AAV-vector DNA into human DNA has been reported with AAV gene therapies. The clinical relevance of individual integration events is unknown, but it is acknowledged that individual integration events could potentially contribute to a risk of tumorigenicity. If a tumor develops in a patient receiving GENGLYCOS, health care providers should contact and report the tumor to Ultragenyx Pharmaceutical Inc. at 1-888-756-8657. Adverse Reactions Seven serious adverse events were observed in the Primary Efficacy Analysis Period (PEAP) of Study 1 (Weeks 1-48), including anaphylaxis/infusion reaction (2), adrenal insufficiency (2), high lactate level (2) and hypoglycemia (1). The most common adverse reactions during the PEAP of Study 1 (occurring in ≥10% of patients) with higher frequency in GENGLYCOS compared to placebo were ALT/AST Enzyme elevated (71%), Nausea (38%), Headache (24%), Hypertriglyceridemia (29%), Adrenal Insufficiency (24%), Constipation (19%), Hyperglycemia (14%), Acne/Dermatitis Acneiform (19%), Cushingoid Features (14%), and Anaphylaxis (10%). DRUG INTERACTIONS Vaccinations Vaccine schedules may need to be adjusted for immunosuppressive therapy, and vaccines should be avoided 1 month prior to GENGLYCOS administration. USE IN SPECIFIC POPULATIONS Pregnancy GENGLYCOS should not be used during pregnancy. There are no data on the use of GENGLYCOS in pregnant women. It is unknown whether GENGLYCOS can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Contraception Women of childbearing potential should use effective contraception for at least 12 months after administration of GENGLYCOS. For 6 months after administration of GENGLYCOS, men must not donate semen, and men of reproductive potential and their female partners must prevent or postpone pregnancy using an effective form of contraception. ADDITIONAL PATIENT COUNSELING INFORMATION Vector Shedding Inform patients/caregivers that vector distribution in blood and vector shedding in urine, stool, and saliva can occur after GENGLYCOS infusion. Advise patients/caregivers on proper hygiene when handling patient body waste. These precautions should be followed for 3 months after GENGLYCOS infusion. Report negative side effects of prescription drugs to the FDA. Visit  or call 1-800-FDA-1088. You may also report side effects to Ultragenyx Pharmaceutical Inc. at 1-888-756-8657. Please see the full Prescribing Information for GENGLYCOS. About Glycogen Storage Disease Type Ia (GSDIa) GSDIa is an ultra-rare, serious, and life-threatening disease due to an inborn error of carbohydrate metabolism caused by pathogenic variants of the G6PC gene, which encodes G6Pase, an enzyme that is critical for the release of glucose from glycogen and other metabolic sources. Deficiency of G6Pase activity results in severe hypoglycemia during periods of fasting between meals and during the night along with excess hepatic glycogen storage, metabolic derangements, and other disease-related complications. Cornstarch is critical in the management of GSDIa throughout the day and night in providing an exogenous source of glucose to help avoid sudden and severe drops in plasma glucose levels; however, current management strategies carry a significant burden to patients and families. GSDIa affects 1,500-2,500 patients in the U.S. and 6,000-8,000 worldwide within commercially accessible geographies. About Ultragenyx Ultragenyx is a biopharmaceutical company committed to bringing novel therapies to patients for the treatment of serious rare and ultra-rare genetic diseases. The company has built a diverse portfolio of approved medicines and treatment candidates aimed at addressing diseases with high unmet medical need and clear biology, for which there are typically no approved therapies treating the underlying disease. The company is led by a management team experienced in the development and commercialization of rare disease therapeutics. Ultragenyx’s strategy is predicated upon time- and cost-efficient drug development, with the goal of delivering safe and effective therapies to patients with the utmost urgency. For more information on Ultragenyx, please visit the company's website at: . Forward-Looking Statements and Use of Digital Media Except for the historical information contained herein, the matters set forth in this press release, including statements regarding the commercial launch, availability and market acceptance of GENGLYCOS; Ultragenyx's ability to manufacture GENGLYCOS at its gene therapy manufacturing facility, scale production and supply GENGLYCOS to Qualified Treatment Centers; patient access to GENGLYCOS, including insurance coverage and reimbursement; the safety, efficacy, durability and potential benefits of GENGLYCOS; estimates of the number of patients with GSDIa and the potential commercial opportunity for GENGLYCOS; the design, enrollment, timing, conduct and results of the post-marketing Disease Monitoring Program and other post-marketing requirements; and Ultragenyx's ability to satisfy FDA requirements and maintain accelerated approval for GENGLYCOS, are forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements involve substantial risks and uncertainties that could cause actual results to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, risks and uncertainties related to the commercial launch and market acceptance of GENGLYCOS; the ability to identify eligible patients and establish and support a network of Qualified Treatment Centers; uncertainty related to insurance coverage and reimbursement; risks related to serious or undesirable side effects, including risks associated with AAV gene therapy; manufacturing risks, including Ultragenyx's limited experience operating its own manufacturing facility and the ability to manufacture and supply GENGLYCOS in sufficient quantities and in compliance with regulatory requirements; Ultragenyx's ability to complete the post-marketing Disease Monitoring Program and other post-marketing requirements within required timeframes and to confirm clinical benefit; the risk that the FDA may modify the approved indication or impose additional requirements, or may withdraw accelerated approval if clinical benefit is not confirmed or post-marketing requirements are not satisfied; smaller than anticipated market opportunities; competition from other therapies or products; product liability; regulatory scrutiny; and other matters that could affect the availability or commercial potential of Ultragenyx's products and product candidates. Ultragenyx undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of Ultragenyx in general, see Ultragenyx's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on August 5, 2026, and its subsequent periodic reports filed with the SEC. In addition to its SEC filings, press releases and public conference calls, Ultragenyx uses its investor relations website and social media outlets to publish important information about the company, including information that may be deemed material to investors, and to comply with its disclosure obligations under Regulation FD. Financial and other information about Ultragenyx is routinely posted and is accessible on Ultragenyx's Investor Relations website ( ) and LinkedIn website ( ). Ultragenyx Contacts Investors Joshua Higa ir@ultragenyx.com Media Jess Rowlands media@ultragenyx.com