Actively Recruiting
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
Led by Sanofi · Updated on 2026-05-05
85
Participants Needed
24
Research Sites
314 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
This is a parallel, Phase 3, two-arm, open-label study to evaluate the efficacy and safety of treatment with fitusiran prophylaxis administered to male pediatric participants (aged 1 to \<12 years) who have severe hemophilia A or B, with or without inhibitory antibodies to FVIII or FIX. Number of participants: Approximately 85 participants will be enrolled into the study: * Approximately 60 fitusiran-naïve participants with severe hemophilia A or B, with or without inhibitors (fitusiran-naïve arm), and * Approximately 25 participants with severe hemophilia A or B with inhibitors rolling over from the EFC15467\* dose confirmation study (roll-over arm). * Fitusiran has been investigated in the pediatric population in study EFC15467, which enrolled male participants aged 1 to \<12 years with hemophilia A or B with inhibitors to examine the safety and tolerability of fitusiran in the pediatric population. Participants will be enrolled into 1 of 2 arms: * Fitusiran-naïve: these participants have not previously received fitusiran, and they will undergo screening and study eligibility assessments. Once enrolled, they will go through a 24-week standard of care (SOC) period before starting fitusiran prophylaxis. * Roll-over participants from the EFC15467 study: only participants who are still on active treatment in study EFC15467 and consenting to study EFC17905 will be eligible to roll over. They will not need to undergo screening or further eligibility assessments. They will directly enroll into the fitusiran treatment period and continue treatment on their current fitusiran dose. The duration of fitusiran treatment will be up to 160 weeks for the fitusiran-naïve arm and up to 60 weeks for the roll-over arm.
CONDITIONS
Official 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: use of bypassing agents for prophylaxis or on-demand bleeding treatment in the last 3 months and meeting Nijmegen-modified Bethesda assay criteria for inhibitor titer
- For non-inhibitor participants: use of clotting factor concentrates for prophylaxis or on-demand treatment in the last 3 months, inhibitor titer less than 0.6 BU/mL, and no bypassing agent use in the last 3 months
- Adequate peripheral venous access for required blood draws
- Ability to provide signed informed consent by parent/legal guardian and assent by 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
- Conditions making participant unsuitable for dosing or study compliance as judged by investigator
- History of multiple drug allergies or allergic reaction to oligonucleotide or GalNAc
- Central or peripheral indwelling catheter with venous access complications requiring hospitalization or anticoagulation in past 12 months
- Planned or recent surgery within 14 days prior to screening or need for additional bypassing agent infusion postoperatively
- History of intolerance to subcutaneous injections
- Current immune tolerance induction therapy
- Use of emicizumab or non-factor bleed management treatment within 6 months prior to screening
- Prior gene therapy
- Participation in another clinical study involving investigational products other than fitusiran during this study
- Antithrombin activity less than 60% at screening
- Co-existing thrombophilic disorder
- Active infection with hepatitis C, acute hepatitis A or E, or acute/chronic hepatitis B
- Platelet count 100,000 per microliter or less
- Acute infection at screening
- HIV positive with CD4 count less than 400 cells per microliter
- Estimated glomerular filtration rate less than 45 mL/min/1.73 m2 using Schwartz formula
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Trial Site Locations
Total: 24 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, 14049-900
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 : 3560002
Mumbai, India, 400022
Actively Recruiting
11
Investigational Site Number : 3560001
Pune, India, 411004
Actively Recruiting
12
Investigational Site Number : 3800002
Florence, Firenze, Italy, 50134
Actively Recruiting
13
Investigational Site Number : 3800001
Milan, Milano, Italy, 20122
Actively Recruiting
14
Investigational Site Number : 3800003
Rozzano, Milano, Italy, 20089
Actively Recruiting
15
Investigational Site Number : 6160002
Wroclaw, Lower Silesian Voivodeship, Poland, 50-556
Actively Recruiting
16
Investigational Site Number : 6420001
Iași, Romania, 700309
Actively Recruiting
17
Investigational Site Number : 6420003
Timișoara, Romania, 300011
Actively Recruiting
18
Investigational Site Number : 7240001
Esplugues de Llobregat, Barcelona [Barcelona], Spain, 08950
Actively Recruiting
19
Investigational Site Number : 7240002
Madrid, Spain, 28046
Actively Recruiting
20
Investigational Site Number : 7240003
Zaragoza, Spain, 50009
Actively Recruiting
21
Investigational Site Number : 1580002
Taichung, Taiwan, 402
Actively Recruiting
22
Investigational Site Number : 1580001
Taipei, Taiwan, 100
Actively Recruiting
23
Investigational Site Number : 7920001
Istanbul, Turkey (Türkiye), 34093
Actively Recruiting
24
Investigational Site Number : 7920002
Izmir, Turkey (Türkiye), 35100
Actively Recruiting
Research Team
T
Trial Transparency email recommended (Toll free for US & Canada)
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here