FASENRA approved in US for hypereosinophilic syndrome
May 14, 2026 – Clinical Trials, Drug Discovery, Other, Pharmaceutical – AstraZeneca, FDA, approvals, hypereosinophilic syndrome, rare diseases
14 May 2026 — Cambridge, UK — 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.
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 FASENRAin patients with HES. 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).
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. This may lead to progressive organ damage over time and if left untreated, may be fatal. 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. 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. It is also approved for SEA in children and adolescents aged 6 years and older in the US and Japan. FASENRA is also approved in more than 70 countries for the treatment of adults with eosinophilic granulomatosis with polyangiitis (EGPA). FASENRA is currently approved in Chile for hypereosinophilic syndrome.
About AstraZeneca
AstraZeneca 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.
