Actively Recruiting
An Open-label, Parallel, Phase 3 Study of Fitusiran Prophylaxis in Male Children Aged 1 to Less Than 12 Years With Severe Hemophilia A or B With or Without Inhibitory Antibodies
Led by Sanofi · Updated on 2026-05-26
85
Participants Needed
27
Research Sites
125 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating the effectiveness and safety of fitusiran prophylaxis in male children aged 1 to less than 12 years who have severe hemophilia A or B, with or without inhibitory antibodies to factors VIII or IX. This is a Phase 3, open-label, parallel study enrolling approximately 85 participants, including those new to fitusiran treatment and those continuing from a previous related study. The trial aims to provide detailed data on bleeding rates and other health outcomes during and after treatment. Participants are divided into two groups: those who have never received fitusiran and those rolling over from an earlier study. The fitusiran-nafve group undergoes a 24-week period of standard care before starting regular subcutaneous injections of fitusiran, which may be adjusted during the study as needed. The roll-over group continues their current fitusiran dose for up to 60 weeks, while the fitusiran-nafve group may receive treatment for up to 160 weeks. Throughout the study, children will have regular assessments including monitoring of bleeding rates, physical activity, pain intensity, and quality of life. Researchers will track any adverse events and changes in joint health. Blood samples and other laboratory tests will be conducted, and participants will be closely observed during and after treatment for safety. Total participation may last several years depending on the treatment arm.
CONDITIONS
Brief Title
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
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Male participants aged 1 to less than 12 years at enrollment
- Severe hemophilia A or B with factor VIII less than 1% or factor IX 2% or less
- For inhibitor participants: requiring bypassing agents for prophylaxis or treatment for at least 3 months before screening with specific inhibitor titer criteria
- For non-inhibitor participants: requiring clotting factor concentrates for prophylaxis or treatment for at least 3 months before screening with low inhibitor titer and no bypassing agent use
- Adequate peripheral venous access for blood draws
- Ability to provide signed informed consent/assent from parent/legal guardian and participant per local regulations
You will not qualify if you...
- Known bleeding disorders other than hemophilia A or B
- Clinically significant liver disease
- History of antiphospholipid antibody syndrome
- History of arterial or venous thromboembolism unrelated to venous access
- Any condition making participant unsuitable for dosing or study compliance
- History of multiple drug allergies or allergic reaction to oligonucleotide or GalNAc
- Central or peripheral indwelling catheter with recent venous access complications
- Anticipated or recent surgery during study period
- History of intolerance to subcutaneous injections
- Current immune tolerance induction therapy
- Use of emicizumab or non-factor bleed management treatment within 6 months
- Prior gene therapy
- Participation in another investigational product or device trial during this study
- Antithrombin activity less than 60% at screening
- Co-existing thrombophilic disorder
- Active hepatitis C, hepatitis A, hepatitis E, or hepatitis B infection
- Platelet count 100,000/mcL or less
- Acute infection at screening
- HIV positive with CD4 count less than 400 cells/mcL
- Estimated glomerular filtration rate less than 45 mL/min/1.73 m2 by Schwartz formula
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 24 weeks
Participants in the fitusiran-naïve arm undergo a 24-week period receiving standard care before starting fitusiran treatment.
Visits as per standard care schedule
Duration - Up to 160 weeks for fitusiran-naïve arm; up to 60 weeks for roll-over arm
Participants receive fitusiran prophylaxis treatment with dose adjustments as needed according to the study protocol.
Regular visits for treatment and monitoring per protocol
Duration - Approximately 24 weeks after treatment completion
Participants are monitored for safety and outcomes after completing fitusiran treatment.
Follow-up visits as scheduled for safety monitoring
Trial Site Locations
Total: 27 locations
1
The Luskin Orthopaedic Institute for Children- Site Number : 8400013
Los Angeles, California, United States, 90007
Actively Recruiting
2
The Center for Inherited Blood Disorders- Site Number : 8400009
Orange, California, United States, 92868
Actively Recruiting
3
Cure 4 The Kids Foundation- Site Number : 8400001
Las Vegas, Nevada, United States, 89147
Actively Recruiting
4
Hackensack Meridian Health - Hackensack University Medical Center- Site Number : 8400008
Hackensack, New Jersey, United States, 07601
Actively Recruiting
5
Investigational Site Number : 0560002
Brussels, Belgium, 1020
Actively Recruiting
6
Investigational Site Number : 0560001
Brussels, Belgium, 1200
Actively Recruiting
7
Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto- Site Number : 0760003
Ribeirão Preto, São Paulo, Brazil, 14051140
Actively Recruiting
8
Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo- Site Number : 0760004
São Paulo, Brazil, 05403-000
Actively Recruiting
9
Investigational Site Number : 1240003
Montreal, Quebec, Canada, H3T 1C5
Actively Recruiting
10
Investigational Site Number : 3560004
Bengaluru, India, 560034
Actively Recruiting
11
Investigational Site Number : 3560002
Mumbai, India, 400022
Actively Recruiting
12
Investigational Site Number : 3560001
Pune, India, 411004
Actively Recruiting
13
Investigational Site Number : 3560003
Vellore, India, 632004
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14
Investigational Site Number : 3800002
Florence, Firenze, Italy, 50134
Actively Recruiting
15
Investigational Site Number : 3800001
Milan, Milano, Italy, 20122
Actively Recruiting
16
Investigational Site Number : 3800003
Rozzano, Milano, Italy, 20089
Actively Recruiting
17
Investigational Site Number : 6160002
Wroclaw, Lower Silesian Voivodeship, Poland, 50-556
Actively Recruiting
18
Investigational Site Number : 6420001
Iași, Romania, 700309
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19
Investigational Site Number : 6420003
Timișoara, Romania, 300011
Actively Recruiting
20
Investigational Site Number : 6820001
Riyadh, Saudi Arabia, 12746
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21
Investigational Site Number : 7240001
Esplugues de Llobregat, Barcelona [Barcelona], Spain, 08950
Actively Recruiting
22
Investigational Site Number : 7240002
Madrid, Spain, 28046
Actively Recruiting
23
Investigational Site Number : 7240003
Zaragoza, Spain, 50009
Actively Recruiting
24
Investigational Site Number : 1580002
Taichung, Taiwan, 402
Actively Recruiting
25
Investigational Site Number : 1580001
Taipei, Taiwan, 100
Actively Recruiting
26
Investigational Site Number : 7920001
Istanbul, Turkey (Türkiye), 34093
Actively Recruiting
27
Investigational Site Number : 7920002
Izmir, Turkey (Türkiye), 35100
Actively Recruiting
Research Team
T
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How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
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