🏛️ Verified NIH Record • Updated 2026-07-09

A Phase III Study to Evaluate the Efficacy and Safety of Benralizumab in Patients With Hypereosinophilic Syndrome (HES) (NCT04191304)

A Multicentre, Randomised, Double-blind, Parallel-group, Placebo-controlled, 24-Week Phase III Study With an Open-label Extension to Evaluate the Efficacy and Safety of Benralizumab in Patients With Hypereosinophilic Syndrome (HES)

🔵 Active, Not Recruiting Phase3 💊 Investigational Drug / Biologic Sponsor: AstraZeneca

🩺 Plain-English Summary (8th-Grade Level)

This is a multicentre, randomised, double-blind (DB), parallel-group, placebo-controlled, 24-week Phase III study to compare the efficacy and safety of benralizumab versus placebo administered by SC injection Q4W in patients with hypereosinophilic syndrome (HES). This study comprises 2 distinct periods (together defined as the 'main study'): A 24-week, DB treatment period, during which patients will be randomised to receive either benralizumab or placebo, in addition to their prior stable HES background therapy, and an open-label extension (OLE) period, during which all patients will receive benralizumab. The primary database lock (DBL) will occur when approximately 38 patients have had their first HES worsening/flare event during the DB treatment period and all randomised patients have had the opportunity to be followed up for the 24-week DB treatment period. A patient must complete the 24-week DB treatment period on investigational product (IP) to be eligible to enter the OLE treatment period. The final DBL will occur after the last patient completes the OLE.

Who can join: Review the eligibility criteria below.

Location: Research Site — La Jolla, California

Age range: 12 Years to 130 Years

🧪 Interventions in This Study

📋 "Do I Qualify?" — 1-Minute Self Screener

Instant Checklist

Full eligibility criteria are available on the official NIH protocol. View the criteria ↗

📍 All Participating Trial Locations (52 Sites)

Showing the first 25 of 52 sites.

  • Research Site — La Jolla, California
  • Research Site — Atlanta, Georgia
  • Research Site — Bethesda, Maryland
  • Research Site — Ann Arbor, Michigan
  • Research Site — Durham, North Carolina
  • Research Site — Cleveland, Ohio
  • Research Site — Columbus, Ohio
  • Research Site — Salt Lake City, Utah
  • Research Site — Rosario,
  • Research Site — Innsbruck,
  • Research Site — Brussels,
  • Research Site — Edegem,
  • Research Site — Chengdu,
  • Research Site — Shanghai,
  • Research Site — Tianjin,
  • Research Site — Xiamen,
  • Research Site — Zhengzhou,
  • Research Site — København Ø,
  • Research Site — Lille,
  • Research Site — Pessac,
  • Research Site — Strasbourg,
  • Research Site — Suresnes,
  • Research Site — Toulouse,
  • Research Site — Hanover,
  • Research Site — Kirchheim,

💰 Cost, Insurance & Patient Rights

  • 100% Free Items: The investigational treatment and protocol-required procedures are supplied at zero cost by the sponsor.
  • Routine Patient Care: Under federal law (ACA § 2709) and many state statutes, routine care costs are covered during participation.
  • Voluntary Participation: You may withdraw at any time without affecting your standard medical care.

More studies in Hypereosinophilic Syndrome

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💡 How to Participate

  1. Check the checklist above to see if you may qualify.
  2. Review the official NIH record below to find the coordinating site.
  3. Ask about the visit schedule, what is covered at no cost, and any travel support.
  4. Confirm with your own doctor before making a decision.
🏛️ View Official NIH Record ↗