Fitusiran Prophylaxis in Male Pediatric Subjects Aged 1 to Less Than 12 Years With Hemophilia A or B (ATLAS-PEDS)

  • End date
    Dec 26, 2026
  • participants needed
  • sponsor
    Genzyme, a Sanofi Company
Updated on 26 April 2022
factor ix
severe haemophilia a
antihemophilic factor
bethesda assay


Primary Objective:

  • To confirm appropriate dose levels of fitusiran when administered to male pediatric participants (ages 1 to <12 years of age) with severe hemophilia A or B

Secondary Objective:

  • To characterize the safety and tolerability
  • To determine fitusiran plasma concentrations at selected time points


The estimated total time on study is up to 160 weeks in participants who roll over into the extension study and up to 184 weeks in participants who do not roll over into the extension study (due to the requirement for up to an additional 6 months of follow-up for monitoring of AT levels).

Condition Hemophilia
Treatment fitusiran
Clinical Study IdentifierNCT03974113
SponsorGenzyme, a Sanofi Company
Last Modified on26 April 2022


Yes No Not Sure

Inclusion Criteria

Male, aged 1 to <12 years at the time of enrollment
Severe hemophilia A or B (Factor VIII (FVIII) <1% or Factor IX (FIX) ≤2%)
Participants must have inhibitory antibodies to FVIII or FIX and must meet one of the following Nijmegen-modified Bethesda assay results criteria
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 (anaphylaxis or nephrotic syndrome)
Adequate peripheral venous access, as determined by the Investigator, to allow the
Weight requirements at the time of enrollment: 8 to <45 kg
blood draws required by the study protocol
Willing and able to comply with the study requirements and to provide signed written informed consent obtained from parent(s)/legal guardian (hereinafter the "parent") and written or oral assent obtained from participant, per local and national requirements

Exclusion Criteria

Known co-existing bleeding disorders other than hemophilia A or B
Antithrombin (AT) activity <60% at Screening
Co-existing thrombophilic disorder
Clinically significant liver disease
Active Hepatitis C virus infection
Acute or chronic Hepatitis B virus infection
Acute Hepatitis A or hepatitis E infection
HIV positive with a CD4 count of <400 cells/μL
History of arterial or venous thromboembolism, unrelated to an indwelling venous access
Inadequate renal function
History of multiple drug allergies or history of allergic reaction to an oligonucleotide or N-Acetylgalactosamine (GalNAc)
Participants with central or peripheral indwelling catheters, with history of venous access complications leading to hospitalization and/or systemic anticoagulation therapy
History of intolerance to subcutaneous (SC) injection(s)
Any other conditions or comorbidities that would make the patient unsuitable for enrollment or could interfere with participation in or completion of the study, per Investigator judgment
The use of emicizumab (Hemlibra®) within 6 months prior to screening
The above information is not intended to contain all considerations relevant to a patient's
potential participation in a clinical trial
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