Fitusiran for Hemophilia A or B in Children
This study is looking at a medicine called fitusiran to see how well it works and if it's safe for boys aged 1 to under 12 years old who have severe hemophilia A or B. Hemophilia is a bleeding disorder where blood doesn't clot properly. Fitusiran is given as a shot under the skin. The study will compare fitusiran to usual care, which might include clotting factor concentrates (CFC) or bypassing agents (BPA), given through a vein. Researchers will measure how many bleeding episodes participants have each year to see if fitusiran helps. We don't have information on the current recruitment status.
- Study design
- This is an open-label Phase 3 study, meaning everyone knows which treatment they are receiving. About 85 boys with hemophilia A or B will participate.
- What's involved
- Participants in the fitusiran-naïve group will receive treatment for up to 160 weeks, and those rolling over from a previous study will receive treatment for up to 60 weeks.
- Compensation
- Not stated in the trial record.
- Follow-up
- The main goal of the study looks at bleeding rates over periods of about 1 to 14 months.
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NCT07285460
A Study to Investigate the Efficacy and Safety of Fitusiran Prophylaxis in Male Participants Aged 1 to Less Than 12 Years With Hemophilia A or B
Recruiting
PHASE3Ages 1–11InterventionalTreatmentSanofi
~85 participants
Updated 2026-08-17 on ClinicalTrials.gov
What's tested:FitusiranClotting factor concentrates (CFC) or bypassing agents (BPA)Antithrombin concentrate (ATIIIC)
At a glance
Recruiting sites
30 of 30 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Annualized treated bleeding rate (ABR) in the fitusiran primary efficacy period and in the SOC period
Measured over Day 85 to Day 421 (fitusiran primary efficacy period); Day -168 to Day -1 (SOC period)
Conditions
Where it's being run
30 sites across 21 statesIndia4
California2
Belgium2
Milano2
Romania2
Spain2
Turkey (Türkiye)2
Nevada1
Who to contact
Trial Transparency email recommended (Toll free for US & Canada)
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Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
Participant must be 1 to \<12 years of age at the time of enrollment.
Participants must have severe hemophilia A or B (FVIII \<1% or FIX ≤2%) as evidenced by a central laboratory measurement at screening or documented medical record evidence.
Participants must meet inhibitor or non-inhibitor status as defined below:
Inhibitor titer of ≥0.6 BU/mL at screening, OR
Inhibitor titer of \<0.6 BU/mL at screening with medical record evidence of 2 consecutive titers ≥0.6 BU/mL, OR
Inhibitor titer of \<0.6 BU/mL at screening with medical record evidence of 1 inhibitor titer ≥0.6 BU/mL and a history of anamnestic response, or severe allergic reaction (eg, anaphylaxis) or nephrotic syndrome
Nijmegen-modified Bethesda assay inhibitor titer of \<0.6 BU/mL at screening, AND
No use of BPA to treat bleeding episodes for at least the last 3 months prior to screening
Participants must have adequate peripheral venous access, as determined by the Investigator, to allow the blood draws required by the study protocol.
Male: There are no contraceptive requirements for this study except where required by local regulations.
Capable of giving signed informed consent/assent. A signed written informed consent must be obtained from parent(s)/legal guardian (hereafter referred to as the "parent"), as well as a written or oral assent obtained from participant, per local and national requirements.
Exclusion
Known co-existing bleeding disorders other than hemophilia A or B.
Presence of clinically significant liver disease.
History of antiphospholipid antibody syndrome.
History of arterial or venous thromboembolism, unrelated to an indwelling venous access
Any condition (eg, medical concern), which in the opinion of the Investigator, would make the participant unsuitable for dosing or which could interfere with the study compliance, the participant's safety and/or the participant's participation in the completion of the treatment period of the study.
History of multiple drug allergies or history of allergic reaction to an oligonucleotide or GalNAc.
Subjects with a central or peripheral indwelling catheter, with a history of venous access complications (such as infections, thrombosis) leading to hospitalization and/or systemic anticoagulation therapy in the last 12 months.
At screening, anticipated need of surgery during the study or planned surgery scheduled to occur during the study.
Completion of a surgical procedure within 14 days prior to screening, or currently receiving additional BPA infusion for postoperative hemostasis.
History of intolerance to SC injection(s).
Current participation in ITI therapy.
The use of emicizumab (Hemlibra®) or any non-factor bleed management treatment within 6 months prior to screening
Prior gene therapy
Current or future participation in another clinical study, scheduled to occur during this study, involving an investigational product other than fitusiran or an investigational device.
AT activity \<60% at screening, as determined by central laboratory analysis.
Co-existing thrombophilic disorder.
Presence of an active Hepatitis C virus infection
Presence of acute hepatitis A or Hepatitis E virus infection.
Presence of acute or chronic hepatitis B virus infection.
Platelet count ≤100 000/μL.
Presence of acute infection at screening.
Human immunodeficiency virus (HIV) positive with a CD4 count of \<400 cells/μL.
Estimated glomerular filtration rate ≤45 mL/min/1.73 m2 (using the Schwartz formula).
What this trial measures
- Annualized treated bleeding rate (ABR) in the fitusiran primary efficacy period and in the SOC periodDay 85 to Day 421 (fitusiran primary efficacy period); Day -168 to Day -1 (SOC period)
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs