Fasenra Approved in US for Hypereosinophilic Syndrome

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14 May 2026 -- AstraZeneca’s Fasenra (benralizumab) has been approved by the US FDA for the treatment of adult and pediatric patients aged 12 years and older with hypereosinophilic syndrome (HES) without an identifiable non-hematologic secondary cause.1

The approval by the US Food and Drug Administration (FDA) was based on positive results from the NATRON Phase III trial that evaluated the efficacy and safety of Fasenra in patients with HES.1,2 In the trial, treatment with Fasenra delayed the time to first HES flare and significantly reduced the risk of first HES flare compared to placebo by 65% (HR 0.35; 95% CI: 0.18-0.69; P=0.0024).1,2

HES is a group of rare disorders characterized by persistently elevated levels of eosinophils (a type of white blood cell) in the blood and evidence of eosinophil-mediated organ or tissue damage.3 This may lead to progressive organ damage over time and if left untreated, may be fatal.3 The most common adverse reactions (≥5% and more common than placebo) with Fasenra in the NATRON study were headache, hypersensitivity reactions (including urticaria, urticaria papular, rash), and influenza like illness.2 For the treatment of HES, the recommended dosage of Fasenra is 30 mg (one injection) administered subcutaneously once every 4 weeks.

Princess U. Ogbogu, Division Chief of Pediatric Allergy, Immunology, and Rheumatology at University Hospitals Rainbow Babies and Children’s Hospital and Case Western Reserve University, Cleveland, OH, and principal investigator of the NATRON trial, said: “The approval of benralizumab for the treatment of HES is an important step forward for patients, providing an additional treatment option. The study demonstrated meaningful reduction in flares while addressing fatigue, a symptom that may impact patients."

Mary Jo Strobel, Executive Director of The American Partnership for Eosinophilic Disorders, said: “People living with hypereosinophilic syndrome struggle every single day. Debilitating fatigue, risk of organ damage, skin manifestations, and other symptoms adversely impact patients’ lives, making it difficult to maintain normal daily activities, including work. Today’s news brings hope to these people and their families.”

James Teague, Vice President, US Respiratory & Immunology and Vaccine & Immune Therapies, AstraZeneca, said: “This approval builds on Fasenra’s foundation in targeting eosinophilic-driven diseases. Fasenra has been shown to reduce flares in hypereosinophilic syndrome, addressing an important need in a population with significant disease burden and few targeted therapies.”

Fasenra is currently approved as an add-on maintenance treatment for severe eosinophilic asthma (SEA) in more than 80 countries, including the US, Japan, EU, China.4-8 It is also approved for SEA in children and adolescents aged 6 years and older in the US and Japan.6 Fasenra is also approved in more than 70 countries for the treatment of adults with eosinophilic granulomatosis with polyangiitis (EGPA).7 Fasenra is currently approved in Chile for hypereosinophilic syndrome.8

IMPORTANT SAFETY INFORMATION

Do not use Fasenra if you are allergic to benralizumab or any of the ingredients in Fasenra. Do not use to treat sudden breathing problems.

Fasenra may cause serious side effects, including

  • allergic (hypersensitivity) reactions, including anaphylaxis. Serious allergic reactions can happen after you get your Fasenra injection. Allergic reactions can sometimes happen hours or days after you get your injection. Tell your healthcare provider or get emergency help right away if you have any of the following symptoms of an allergic reaction
  • swelling of your face, mouth and tongue
  • breathing problems
  • fainting, dizziness, feeling lightheaded (low blood pressure)
  • rash
  • hives

    • Before using Fasenra, tell your healthcare provider about all of your medical conditions, including if you:

  • are taking oral or inhaled corticosteroid medicines. Do not stop taking your corticosteroid medicines unless instructed by your healthcare provider. This may cause other symptoms that were controlled by the corticosteroid medicine to come back
  • have a parasitic (helminth) infection
  • are pregnant or plan to become pregnant. It is not known if Fasenra will harm your unborn baby. Tell your healthcare provider if you become pregnant during your treatment with Fasenra
  • are breastfeeding or plan to breastfeed. It is not known if Fasenra passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you use Fasenra
  • are taking prescription and over-the-counter medicines, vitamins, or herbal supplements.

    • Do not stop taking your other medicines unless instructed to do so by your healthcare provider. Tell your healthcare provider if your condition does not get better or if it gets worse after you start treatment with Fasenra.

    The most common side effects of Fasenra:

  • adults and children 6 years and older with asthma include headache and sore throat
  • adults with EGPA include headache
  • adults and children 12 years and older with HES include headache, allergic reactions, and flu-like symptoms

    • These are not all the possible side effects of Fasenra.

    Approved Use

    Fasenra is a prescription medicine used:

  • with other asthma medicines for the maintenance treatment of asthma in adults and children 6 years and older whose asthma is not controlled with their current asthma medicines. Fasenra is not used to treat sudden breathing problems.
  • to treat adults with eosinophilic granulomatosis with polyangiitis (EGPA).
  • to treat adults and children 12 years and older with hypereosinophilic syndrome (HES).

    • Hypereosinophilic Syndrome

    People with HES experience a wide variety of symptoms depending on the organs that are impacted, which can make it difficult to diagnose.3 Symptoms may include weight loss, fever, cough, chest pain, abdominal pain, skin rash, and neurologic symptoms.3,10 HES can lead to organ or tissue damage over time. The true incidence and prevalence of HES remain unknown, but it is estimated that the prevalence in the US is 0.3-6.3 cases per 100,000 persons.10

    Phase III NATRON Trial

    NATRON was a phase III, multicenter, randomized, double-blind, parallel-group, placebo-controlled study evaluating the efficacy and safety of Fasenra 30 mg versus placebo administered subcutaneously every four weeks in eligible people with HES.2 The primary efficacy endpoint was time to first HES worsening/flare defined as HES clinical manifestations or lab abnormalities that result in an increase/burst of oral corticosteroids (OCS) ≥10 mg/day for at least 2 days, or an increase or addition of new cytotoxic and/or immunosuppressive therapy or hospitalization.2

    Participants (n=133) were randomized in a 1:1 ratio to receive Fasenra 30 mg or placebo administered subcutaneously every 4 weeks during the 24 week double-blind treatment period, while continuing their stable HES therapy.2

    The trial successfully met the primary endpoint, as treatment with Fasenra delayed the time to first HES flare and resulted in a significant 65% reduction in the risk of first flare versus placebo (HR: 0.35; 95% CI: 0.18, 0.69; P=0.0024).1,2 Key secondary endpoints included the proportion of patients with HES flares, annualized rate of HES flares, and change from baseline to Week 24 in PROMIS Fatigue scores.2

    Fasenra

    Fasenra was developed by AstraZeneca and is in-licensed from BioWa, Inc., a wholly owned subsidiary of Kyowa Kirin Co., Ltd., Japan.

    AstraZeneca in Respiratory & Immunology

    Respiratory & Immunology, part of AstraZeneca BioPharmaceuticals, is a key disease area and growth driver to the Company.

    AstraZeneca is an established leader in respiratory care with a 50-year heritage and a growing portfolio of medicines in immune-mediated diseases. The Company is committed to addressing the vast unmet needs of these chronic, often debilitating diseases with a pipeline and portfolio of inhaled medicines, biologics and new modalities aimed at previously unreachable biologic targets.

    AstraZeneca

    AstraZeneca (LSE/STO/NYSE: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialization of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca’s innovative medicines are sold in more than 125 countries and used by millions of patients worldwide. Please visit astrazeneca-us.com and follow the Company on social media @AstraZeneca. The contents of AstraZeneca’s website do not form part of this document and no one should rely on such websites or the contents thereof in reading this document.

    References:

    1. Fasenra® (benralizumab) [package insert]. Wilmington, DE: AstraZeneca Pharmaceuticals LP; 2026.

    2. Ogbogu PU, Roufosse F, Akuthota P, et al. Benralizumab versus placebo for hypereosinophilic syndrome: a randomized, placebo-controlled phase 3 trial. Nat Med. Published online March 31, 2026. doi:10.1038/s41591-026-04315-8

    3. Mikhail ES, Ghatol A. Hypereosinophilic Syndrome. In: StatPearls. Treasure Island (FL): StatPearls Publishing; January 11, 2024.

    4. Fasenra, INN-benralizumab - EMA. European Medicines Agency. Accessed April 2026. https://www.ema.europa.eu/en/documents/product-information/Fasenra-epar-product-information_en.pdf.

    5. AstraZeneca news release. Accessed April 2026 https://www.astrazeneca.com/media-centre/press-releases/2024/Fasenra-approved-in-china-for-the-treatment-of-severe-eosinophilic-asthma.html.

    6. AstraZeneca news release. Accessed April 2026 https://www.astrazeneca.com/media-centre/press-releases/2018/Fasenra-recieves-approval-in-japan-19012018.html.

    7. AstraZeneca Annual Report 2025. Accessed April 2026 https://www.astrazeneca.com/investor-relations/annual-reports/annual-report-2025.html.

    8. Instituto de Salud Pública Fasenra Product Sheet. Accessed April 2026. https://registrosanitario.ispch.gob.cl/Ficha.aspx?RegistroISP=B-2936%2f22.

    9. MSD Manuals. Eosinophilic Disorders. Accessed April 2026. https://www.msdmanuals.com/home/blood-disorders/white-blood-cell-disorders/eosinophilic-disorders.

    10. Khoury P, Chung Y, Carstens D, et al. Prediction model to identify patients with hypereosinophilic syndrome using real-world data. J Allergy Clin Immunol Glob. 2025;5(1):100588. doi:10.1016/j.jacig.2025.100588

    Source: AstraZeneca

    Source: HealthDay

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    Posted : 2026-05-19 16:36

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