🏛️ Verified NIH Record • Updated 2026-02-02

A Study to Test a Medicine (Fitusiran) Injected Under the Skin for Preventing Bleeding Episodes in Male Adolescent or Adult Participants With Severe Hemophilia (NCT05662319)

A Phase 3, Single-arm, Multicenter, Multinational, Open-label, One-way Crossover Study to Investigate the Efficacy and Safety of Fitusiran Prophylaxis in Male Participants Aged ≥ 12 Years With Severe Hemophilia A or B With or Without Inhibitory Antibodies to Factor VIII or IX

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

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

This is a multicenter, multinational, open-label, one-way cross-over, Phase 3, single-arm study for treatment of hemophilia. The purpose of this study is to measure the frequency of treated bleeding episodes with fitusiran in male adult and adolescent (≥12 years old) participants with hemophilia A or B, with or without inhibitory antibodies to factor VIII or IX who have switched from their prior standard of care treatment. The total study duration will be up to approximately 50 months (200 weeks, 1 study month is equivalent to 4 weeks) and will include: * A screening period up to approximately 60 days, * A standard of care (SOC) period of approximately 6 study months (24 weeks), * A fitusiran treatment period of approximately 36 study months (144 weeks), * An antithrombin (AT) follow-up period of approximately 6 study months (24 weeks) but may be shorter or longer depending on individual participants AT recovery. The frequency for telephone visits will be approximately every 2 weeks. For site visits the frequency will be approximately every 8 weeks during the SOC period and approximately every 4 weeks during the fitusiran treatment period. If applicable and if allowed by local regulation, home and/or remote visits may be conducted during the study

Who can join: Review the eligibility criteria below.

Location: Center for Inherited Blood Disorders (CIBD) Site Number : 8400012 — Orange, California

Age range: 12 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 (50 Sites)

Showing the first 25 of 50 sites.

  • Center for Inherited Blood Disorders (CIBD) Site Number : 8400012 — Orange, California
  • M Health Fairview University of Minnesota Medical Center - West Bank- Site Number : 8400016 — Minneapolis, Minnesota
  • Hackensack University Site Number : 8400009 — Hackensack, New Jersey
  • Northwell Health Hemostasis and Thrombosis Center Site Number : 8400015 — New Hyde Park, New York
  • University Hospitals of Cleveland Site Number : 8400001 — Cleveland, Ohio
  • UPMC Children's Hospital of Pittsburgh-4401 Penn Ave Site Number : 8400017 — Pittsburgh, Pennsylvania
  • Children's Medical Center Dallas- Site Number : 8400018 — Dallas, Texas
  • Gulf States Hemophilia and Thrombophilia Center- Site Number : 8400002 — Houston, Texas
  • Investigational Site Number : 1240001 — Hamilton, Ontario
  • Investigational Site Number : 1240002 — Hamilton, Ontario
  • Investigational Site Number : 1240004 — Toronto, Ontario
  • Investigational Site Number : 1560003 — Beijing,
  • Investigational Site Number : 1560001 — Guangzhou,
  • Investigational Site Number : 1560002 — Jinan,
  • Investigational Site Number : 2500003 — Le Kremlin-Bicêtre,
  • Investigational Site Number : 2500002 — Lille,
  • Investigational Site Number : 2500001 — Paris,
  • Investigational Site Number : 2760001 — Berlin,
  • Investigational Site Number : 2760002 — Hamburg,
  • Investigational Site Number : 3000001 — Athens,
  • Investigational Site Number : 3000002 — Athens,
  • Investigational Site Number : 3560004 — Bangalore,
  • Investigational Site Number : 3560007 — Bhubaneswar,
  • Investigational Site Number : 3560001 — Pune-411011,
  • Investigational Site Number : 3560006 — Punjab,

💰 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.

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Explore by condition: All Hemophilia clinical trials

💡 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 ↗