A Study to Test a Medicine (Fitusiran) for Preventing Bleeds in People With Severe Hemophilia Who Previously Received Preventive Treatment With Emicizumab

{ "A Study of Fitusiran for Severe Hemophilia A After Emicizumab Treatment", "This study is looking at the safety of switching from emicizumab to fitusiran (SAR439774) for preventing bleeds in people with severe hemophilia A. You might be able to join if you are a male, at least 12 years old, have severe hemophilia A (a bleeding disorder where your blood doesn't clot properly), and have previously received emicizumab to prevent bleeds. The study will check for any side effects (adverse events) that happen during the first four months of fitusiran treatment. This study is currently unclear about its recruitment status and plans to enroll 20 participants.", "design": "This is an exploratory, single-group study (meaning everyone receives the same treatment) in its fourth phase. It aims to enroll 20 male participants.", "commitments": "The study duration will be up to approximately 28 months, including about a 2-month screening period.", "compensation": "Not stated in the trial record.", "follow_up": "The primary safety measure is observed during the fitusiran treatment, from Day 1 up to Month 4.", }

Study design: Not specified.
What's involved: Not specified in the trial record.
Compensation: Not stated in the trial record.
Follow-up: Not specified.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

A Study to Test a Medicine (Fitusiran) for Preventing Bleeds in People With Severe Hemophilia Who Previously Received Preventive Treatment With Emicizumab

Recruiting

PHASE4Ages 12+InterventionalTreatment

Sanofi

~20 participants

Updated 2026-06-02 on ClinicalTrials.gov

What's tested:Fitusiran (SAR439774)Clotting factor concentrates (CFC) or bypassing agents (BPA)Antithrombin concentrate (ATIIIC)Emicizumab

At a glance

Recruiting sites

2 of 2 listed sites are recruiting right now

RecruitingSuspended, closed, or not yet open

What they're measuring

Number of participants with Adverse events (AEs) during the fitusiran treatment

Measured over From Day 1 up to Month 4

Conditions

Hemophilia A

Where it's being run

2 sites across 2 states

California1

Podlaskie1

Study leadership

Clinical Sciences & Operations · STUDY_DIRECTOR · Sanofi

Who to contact

Trial Transparency email recommended (Toll free for US & Canada)

[email protected]

800-633-1610 · ext. option 6

Email the study team

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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.

Check eligibility for this trial ~2 min · HIPAA-protected · delete anytime

Eligibility criteria

Inclusion

Male participants must be ≥12 years of age inclusive, at the time of signing the informed consent

Diagnosis of severe congenital hemophilia A (FVIII \< 1%) as evidenced by a central laboratory measurement at screening or documented medical record evidence.

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 anamnestic response.

Participants who are currently on the full labeled dose of emicizumab prophylaxis, irrespective of inhibitor/non-inhibitor status.

Signed informed consent/assent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.

Exclusion

Known coexisting bleeding disorders

History of antiphospholipid antibody syndrome.

History of arterial or venous thromboembolism, atrial fibrillation, significant valvular disease, myocardial infarction, angina, transient ischemic attack, or stroke. Participants who have experienced thrombosis associated with indwelling venous access may be enrolled.

Presence of clinically significant liver disease

Current or prior participation in a fitusiran trial

Current or prior participation in a gene therapy trial

AT activity \<60% at Screening, as determined by central laboratory measurement

Coexisting thrombophilic disorder - Hepatitis C virus antibody positive, except participants who have negative Hepatitis C viral load and no evidence of cirrhosis

Presence of acute hepatitis, ie, hepatitis A, hepatitis E.

Presence of acute or chronic hepatitis B infection

Known to be HIV positive with CD4 count \<200 cells/μL.

Reduced renal function

What this trial measures

Number of participants with Adverse events (AEs) during the fitusiran treatmentFrom Day 1 up to Month 4
Incidence, severity, and seriousness, of AEs occurred during fitusiran treatment period will be reported

Trialytics