FITUSIRAN for Hemophilia A | Hemophilia B

Inclusion criteria

• {"criterion_text":"- Participant must be 1 to <12 years of age at the time of enrollment\n- Participants must have severe hemophilia A or B (FVIII <1% or FIX ≤2%) as evidenced by a central laboratory measurement at screening or documented medical record evidence.\n--Participants must meet inhibitor or non-inhibitor status as defined below: Inhibitor: Requiring use of BPA for prophylaxis or BPA as on-demand therapy for any bleeding episodes for at least the last 3 months prior to screening, and 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 (eg, anaphylaxis) or nephrotic syndrome Non-inhibitor: Requiring use of clotting factor concentrates (CFCs) for prophylaxis or CFCs as on- demand therapy for any bleeding episodes for at least the last 3 months prior to screening, and meet each of the following criterion: . Nijmegen-modified Bethesda assay inhibitor titer of <0.6 BU/mL at screening, AND . No use of BPA to treat bleeding episodes for at least the last 3 months prior to screening\n- -Participants must have adequate peripheral venous access, as determined by the Investigator, to allow the blood draws required by the study protocol.\n- -Male: There are no contraceptive requirements for this study except where required by local regulations.\n- -Capable of giving signed informed consent/assent. A signed written informed consent must be obtained from parent(s)/legal guardian (hereafter referred to as the “parent”), as well as a written or oral assent obtained from participant, per local and national requirements."}

Exclusion criteria

• {"criterion_text":"- Known co-existing bleeding disorders other than hemophilia A or B.\n- Presence of clinically significant liver disease.\n- Presence of acute or chronic hepatitis B virus infection.\n- Presence of acute hepatitis A or Hepatitis E virus infection.\n- Presence of an active Hepatitis C virus infection\n- Platelet count ≤100 000/μL.\n- Presence of acute infection at screening.\n- Human immunodeficiency virus (HIV) positive with a CD4 count of <400 cells/μL.\n- Estimated glomerular filtration rate ≤45 mL/min/1.73 m2 (using the Schwartz formula).\n- History of antiphospholipid antibody syndrome.\n- History of arterial or venous thromboembolism, unrelated to an indwelling venous access.\n- Any condition (eg, medical concern), which in the opinion of the Investigator, would make the participant unsuitable for dosing or which could interfere with the study compliance, the participant's safety and/or the participant's participation in the completion of the treatment period of the study.\n- History of multiple drug allergies or history of allergic reaction to an oligonucleotide or GalNAc.\n- Subjects with a central or peripheral indwelling catheter, with a history of venous access complications (such as infections, thrombosis) leading to hospitalization and/or systemic anticoagulation therapy in the last 12 months.\n- At screening, anticipated need of surgery during the study or planned surgery scheduled to occur during the study.\n- Completion of a surgical procedure within 14 days prior to screening, or currently receiving additional BPA infusion for postoperative hemostasis.\n- The use of emicizumab (Hemlibra®) or any non-factor bleed management treatment within 6 months prior to screening\n- Prior gene therapy\n- Current participation in ITI therapy.\n- Current or future participation in another clinical study, scheduled to occur during this study, involving an investigational product other than fitusiran or an investigational device.\n- AT activity <60% at screening, as determined by central laboratory analysis.\n- Co-existing thrombophilic disorder."}

Primary endpoints

• {"endpoint_text":"- Annualized treated bleeding rate (ABR) in the fitusiran primary efficacy period and in the SOC period.","definition_or_measurement_approach":"Annualized treated bleeding rate (ABR): the annualized rate of treated bleeding episodes measured during the fitusiran primary efficacy period and during the standard-of-care (SOC) period."}

Secondary endpoints

• {"endpoint_text":"- Annualized spontaneous bleeding rate (AsBR) in the fitusiran primary efficacy period and in the SOC period.","definition_or_measurement_approach":"AsBR: annualized rate of spontaneous bleeding episodes measured during the specified periods."}
• {"endpoint_text":"- Annualized joint bleeding rate (AjBR) in the fitusiran primary efficacy period and in the SOC period","definition_or_measurement_approach":"AjBR: annualized rate of joint bleeding episodes measured during the specified periods."}
• {"endpoint_text":"- ABR in the fitusiran treatment period (160 weeks) for fitusiran-naïve participants.","definition_or_measurement_approach":"ABR measured over the 160-week fitusiran treatment period for fitusiran-naïve participants."}
• {"endpoint_text":"- ABR in the fitusiran treatment period (60 weeks) for rolled-over participants","definition_or_measurement_approach":"ABR measured over the 60-week fitusiran treatment period for rolled-over participants."}
• {"endpoint_text":"- Change in physical activity","definition_or_measurement_approach":"Change from baseline in physical activity (measurement instrument not specified in provided data)."}
• {"endpoint_text":"- Change in pain intensity","definition_or_measurement_approach":"Change from baseline in pain intensity (measurement instrument not specified in provided data)."}
• {"endpoint_text":"- Change in HRQoL","definition_or_measurement_approach":"Change from baseline in health-related quality of life (HRQoL) outcomes (instrument not specified in provided data)."}
• {"endpoint_text":"- Incidence, severity, seriousness, and relatedness of adverse events (AEs)","definition_or_measurement_approach":"Standard adverse event reporting: incidence, severity, seriousness and investigator-assessed relatedness of AEs."}
• {"endpoint_text":"- Change in total score and domain scores","definition_or_measurement_approach":"Change from baseline in total and domain scores (specific instrument not specified in provided data)."}
• {"endpoint_text":"- Target joints resolution","definition_or_measurement_approach":"Resolution of target joints as assessed during study visits (definition not specified in provided data)."}

Methods

• Flyers (country-specific flyers referenced: IT, FR, NL, EN, DE, ES, PL, RO)
• Doctor-to-doctor referral letters (country-specific: IT, NL, FR, DE, ES, RO)
• Video/storyboard materials (UYS/JUMO videos referenced for IT, EN, FR, NL, DE, ES)
• Prescreener / 'understanding your study' materials (referenced for ES, RO)
• Webpage recruitment material (Sanofi studies webpage referenced for ES)
• GP letter (Italy: GP-letter referenced)

Hungary

Earliest CTIS Part Ii Submission Date

17-11-2025

Latest Decision Or Authorization Date

16-01-2026

Processing Time Days

60

Number Of Sites

1

Number Of Participants

2

Italy

Earliest CTIS Part Ii Submission Date

01-12-2025

Latest Decision Or Authorization Date

16-01-2026

Processing Time Days

46

Number Of Sites

4

Number Of Participants

6

Belgium

Earliest CTIS Part Ii Submission Date

28-11-2025

Latest Decision Or Authorization Date

20-03-2026

Processing Time Days

112

Number Of Sites

2

Number Of Participants

2

Germany

Earliest CTIS Part Ii Submission Date

12-12-2025

Latest Decision Or Authorization Date

13-03-2026

Processing Time Days

91

Number Of Sites

1

Number Of Participants

4

Spain

Earliest CTIS Part Ii Submission Date

15-12-2025

Latest Decision Or Authorization Date

24-03-2026

Processing Time Days

99

Number Of Sites

3

Number Of Participants

3

Poland

Earliest CTIS Part Ii Submission Date

28-11-2025

Latest Decision Or Authorization Date

20-04-2026

Processing Time Days

143

Number Of Sites

3

Number Of Participants

4

Romania

Earliest CTIS Part Ii Submission Date

28-11-2025

Latest Decision Or Authorization Date

11-05-2026

Processing Time Days

164

Number Of Sites

3

Number Of Participants

5

Primary sponsor

Full Name

Sanofi-Aventis Recherche & Developpement

Organisation Type

Pharmaceutical company

Country Of Registered Address

France

Contract research organisations

Name

Eresearchtechnology Inc.

Responsibilities

sponsorDuties code: 7 (contact: customercare@clario.com)

Name

ESMS Global Limited

Responsibilities

Centralized 24-Hour Emergency System: eSMS

Name

CoagScope B.V.

Responsibilities

sponsorDuties code: 4

Name

Labcorp Central Laboratory Services LP

Responsibilities

central laboratory services (sponsorDuties code: 4; contact: Mahsa.Taleb@labcorp.com)

Third parties

• {"country":"United States","full_name":"Eresearchtechnology Inc.","duties_or_roles":"sponsorDuties code: 7","organisation_type":"Pharmaceutical company"}
• {"country":"United Kingdom","full_name":"ESMS Global Limited","duties_or_roles":"Centralized 24-Hour Emergency System: eSMS (sponsorDuties code: 15)","organisation_type":"Pharmaceutical company"}
• {"country":"Netherlands","full_name":"CoagScope B.V.","duties_or_roles":"sponsorDuties code: 4","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Labcorp Central Laboratory Services LP","duties_or_roles":"sponsorDuties code: 4","organisation_type":"Pharmaceutical company"}