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

NCT ID: NCT06145373

Last Updated: 2025-09-30

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE4

Total Enrollment

20 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-03-01

Study Completion Date

2029-11-30

Brief Summary

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This is an exploratory, single group, Phase 4, study to assess treatment with fitusiran prophylaxis after switching from emicizumab prophylaxis.

This study aims to evaluate the safety and tolerability of switching to fitusiran after a transition period from the last dose of emicizumab. The study will be conducted in male participants with severe hemophilia A, with or without inhibitors, aged ≥12 years, who were previously receiving emicizumab prophylaxis.

Study details include:

* The study duration will be up to approximately 28 months:

* There will be an approximately 2-month screening period.
* There will be an approximately 2-month period before fitusiran treatment starts (pre-fitusiran treatment period)
* The fitusiran treatment duration will be up to 18-months (fitusiran treatment period)
* The antithrombin (AT) follow-up (FU) period will be approximately 6 months after the last dose of fitusiran (during which the AT activity level will be monitored at approximately monthly intervals following the final fitusiran dose until AT activity levels return to at least 60%).
* The study site visits are scheduled at monthly/ every 2 months intervals of 28 days (4 weeks) / 56 days (8 weeks), respectively, during the fitusiran treatment period.

Detailed Description

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Conditions

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Hemophilia A

Study Design

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Allocation Method

NA

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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fitusiran

The pre-fitusiran treatment period is defined as the transition period up to the first fitusiran administration. Participants will receive on demand or prophylactic treatment with intravenous clotting factor concentrates (IV CFCs) or bypassing agents (BPAs) from Month-2 until Day 1.

Fitusiran treatment period: Participants will receive subcutaneous (SC) fitusiran prophylaxis once every 2 months (Q2M) or once monthly (QM) from Day 1 until Month18.

Participants may receive IV antithrombin concentrate (ATIIIC) upon investigator's judgement.

AT FU period: Participants will be followed up until AT activity levels recover to at least 60% (per central laboratory).

In case of bleeding events participants will receive IV CFCs or BPAs. Participants may receive IV ATIIIC upon investigator's judgement.

Group Type EXPERIMENTAL

Fitusiran (SAR439774)

Intervention Type DRUG

Pharmaceutical form:Solution for injection-Route of administration:Subcutaneous (SC) injection

Clotting factor concentrates (CFC) or bypassing agents (BPA)

Intervention Type BIOLOGICAL

Pharmaceutical form: Solution for injection-Route of administration: Intravenous (IV) injection

Antithrombin concentrate (ATIIIC)

Intervention Type BIOLOGICAL

Pharmaceutical form:Solution for injection-Route of administration:Intravenous (IV) injection

Emicizumab

Intervention Type BIOLOGICAL

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

Interventions

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Fitusiran (SAR439774)

Pharmaceutical form:Solution for injection-Route of administration:Subcutaneous (SC) injection

Intervention Type DRUG

Clotting factor concentrates (CFC) or bypassing agents (BPA)

Pharmaceutical form: Solution for injection-Route of administration: Intravenous (IV) injection

Intervention Type BIOLOGICAL

Antithrombin concentrate (ATIIIC)

Pharmaceutical form:Solution for injection-Route of administration:Intravenous (IV) injection

Intervention Type BIOLOGICAL

Emicizumab

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

Intervention Type BIOLOGICAL

Other Intervention Names

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SAR439774, Qfitlia®

Eligibility Criteria

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Inclusion Criteria

* 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 Criteria

Participants are excluded from the study if any of the following criteria apply:

* 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

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.
Minimum Eligible Age

12 Years

Eligible Sex

MALE

Accepts Healthy Volunteers

No

Sponsors

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Sanofi

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Clinical Sciences & Operations

Role: STUDY_DIRECTOR

Sanofi

Locations

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Children's Hospital Los Angeles- Site Number : 8400005

Los Angeles, California, United States

Site Status RECRUITING

Investigational Site Number : 1580001

Taipei, Podlaskie, Taiwan

Site Status RECRUITING

Countries

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United States Taiwan

Central Contacts

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

Role: CONTACT

800-633-1610 ext. option 6

Related Links

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Other Identifiers

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2022-502414-84

Identifier Type: REGISTRY

Identifier Source: secondary_id

U1111-1280-7227

Identifier Type: REGISTRY

Identifier Source: secondary_id

SFY17741

Identifier Type: -

Identifier Source: org_study_id

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