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Study identifier: NCT05611801 Synced from ClinicalTrials.gov · July 29, 2026
● Recruiting

A Clinical Trial of Study Medicine (Marstacimab) in Pediatric Patients With Hemophilia A or Hemophilia B

Condition: Hemophilia A · Hemophilia B  ·  Sponsor: Pfizer

PhasePhase 3
Planned participants100
Who can joinMale, 1 Year to 17 Years
Healthy volunteersNo

About this study

The purpose of this clinical trial is to learn about the safety and effects of the study medicine (called marstacimab) for the potential treatment of hemophilia in pediatric patients. This study will enroll pediatric participants from ages 1 to 17 years in a sequential manner. The study will open enrollment to adolescent participants aged 12 to 17 years first. Then children aged 6 to 11 years will be permitted to enroll. Lastly, children aged 1 to 5 years will be permitted to enroll. This study will enroll participants who: * have severe Hemophilia A or moderately severe to severe Hemophilia B (with or without inhibitors) * have accurate historical records documenting all factor VIII, factor IX, or bypass agent infusions and hemophilia bleed events for at least 1 year prior to entering the study * if a non-inhibitor patient, must be on a stable routine prophylaxis regimen with factor VIII or factor IX replacement products for at least 12 months prior to study entry * if an inhibitor patient, must be on an on-demand bypass treatment regimen during the 12 months prior to study entry All participants in this study will receive marstacimab to use prophylactically. Marstacimab will be given once a week as a subcutaneous (under the skin) shot. The first dose of marstacimab will be given at the study site by the study site staff. During the 12-month treatment period, weekly doses of marstacimab can be given at home, or if preferred, the doses may be given by the study site staff…

This description comes directly from the study's public registry record.

Talk to the study team

Pfizer CT.gov Call Center  ·  1-800-718-1021  ·  ClinicalTrials.gov_Inquiries@pfizer.com

Always discuss trial participation with your own doctor first.

Locations (34)

Arbesu HematologíaMendoza, ArgentinaRecruiting
Murdoch Children's Research InstituteParkville, AustraliaRecruiting
Medizinische Universität WienVienna, State of Vienna, AustriaRecruiting
Hamilton Health Sciences - McMaster University Medical CentreHamilton, Ontario/canada, CanadaRecruiting
Tongji Hospital of Tongji Medical College of Huazhong University of Science and TechnologyWuhan, Hubei, ChinaRecruiting
Tongji Hospital of Tongji Medical College of HUST/Pediatric Hematology Department PharmacyWuhan, Hubei, ChinaRecruiting
Institute of hematology&blood disease hospitalTianjin, Tianjin Municipality, ChinaRecruiting
Detska nemocnice FN BrnoBrno, Brno-město, CzechiaRecruiting
Motol University HospitalPrague, CzechiaRecruiting
RigshospitaletCopenhagen, Capital Region, DenmarkRecruiting
Aarhus Universitetshospital, SkejbyAarhus N, DenmarkRecruiting
Charité Campus Virchow-KlinikumBerlin, GermanyRecruiting

+ 22 more locations — full list on the registry record.

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Source record: clinicaltrials.gov/study/NCT05611801