Fitusiran Prophylaxis in Male Pediatric Subjects Aged 1 to Less Than 12 Years With Hemophilia A or B

NCT03974113 | Active Not Recruiting Phase 3 DMC FDA Drug

• 4 other identifiers: EFC15467U1111-1223-43682024-512501-762019-000679-18
• Study Type: interventional
• Target: 32
• Locations: 6 countries
• Sites: 16

Brief Summary

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 Objectives:

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

Conditions

Hemophilia

Outcome Measures

Primary Outcomes (1)

• Plasma antithrombin (AT) activity levels

  Characterize the AT activity at the optimal therapeutic dose

  Day 1 to the AT analysis time point at the optimal therapeutic dose (approximately 256 weeks)

Secondary Outcomes (2)

• Number of participants reported with adverse events

  Up to 280 weeks (up to 256 weeks of treatment + up to 24 weeks of AT follow up)

• Fitusiran plasma concentrations

  Day 1 and Day 85

Study Arms (1)

Fitusiran

EXPERIMENTAL

Participants will receive a selected dose of fitusiran at regular intervals, as per study protocol

Drug: Fitusiran

Interventions

Fitusiran DRUG

Pharmaceutical form:Solution for injection-Route of administration:Subcutaneous

Also known as: SAR439774

Fitusiran

Eligibility Criteria

• Age: 1 Year - 11 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• 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 blood draws required by the study protocol
• Weight requirements at the time of enrollment: 8 to \<45 kg
• 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

You may not qualify if:

• Participants are excluded from the study if any of the following criteria apply:
• 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)
• Subjects 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)
• Use of emicizumab (Hemlibra®) within 6 months prior to screening

Sponsors & Collaborators

• Genzyme, a Sanofi Company: lead

Study Sites (16)

Children's Hospital Los Angeles Site Number : 8400002

Los Angeles, California, 90027, United States

Location

Hackensack University Medical Center- Site Number : 8400008

Hackensack, New Jersey, 07601, United States

Location

University Hospitals of Cleveland- Site Number : 8400007

Cleveland, Ohio, 44106, United States

Location

Penn State Milton S. Hershey Medical Center- Site Number : 8400006

Hershey, Pennsylvania, 17033, United States

Location

Investigational Site Number : 1240001

Hamilton, Ontario, L8N 3Z5, Canada

Location

Investigational Site Number : 1240002

Ottawa, Ontario, K1H 8L1, Canada

Location

Investigational Site Number : 3560006

Bangalore, 560034, India

Location

Investigational Site Number : 3560002

Mumbai, 400 022, India

Location

Investigational Site Number : 3560001

Pune-411011, 411 011, India

Location

Investigational Site Number : 3560004

Vellore, 632004, India

Location

Investigational Site Number : 3800002

Florence, 50134, Italy

Location

Investigational Site Number : 3800001

Milan, 20122, Italy

Location

Investigational Site Number : 7240002

Madrid, Madrid, Comunidad de, 28046, Spain

Location

Investigational Site Number : 7920001

Adana, 01130, Turkey (Türkiye)

Location

Investigational Site Number : 7920002

Istanbul, 34093, Turkey (Türkiye)

Location

Investigational Site Number : 7920003

Izmir, TR-35100, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Hemophilia A

Interventions

fitusiran

Condition Hierarchy (Ancestors)

Blood Coagulation Disorders, Inherited; Blood Coagulation Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Coagulation Protein Disorders; Hemorrhagic Disorders; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Clinical Sciences & Operations

  Sanofi

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 3, 2019
• First Posted: June 4, 2019
• Study Start: January 28, 2020
• Primary Completion (Estimated): August 15, 2026
• Study Completion (Estimated): December 15, 2026
• Last Updated: August 8, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share

Locations

US (4); ES (1); TU (3); CA (2); IT (2); IN (4)