A Clinical Trial of Study Medicine (Marstacimab) in Pediatric Patients With Hemophilia A or Hemophilia B
NCT ID: NCT05611801
Last Updated: 2025-08-14
Study Results
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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RECRUITING
PHASE3
100 participants
INTERVENTIONAL
2022-12-09
2028-09-10
Brief Summary
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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.
To help us determine if the study medicine is safe and effective, we will compare participant experiences when they are taking the study medicine to a historical period when they were not. Researchers want to see if the study medicine works to prevent the bleeding episodes commonly experienced by patients with Hemophilia.
Participants will be in this study for about 14 months (approximately 1 month in a Screening period, 12 months receiving treatment, and 1 month in a follow-up period) during which they will visit the study site at least 10 times. If preferred, and if local regulations allow it, 2 of the study visits can be completed at the participant's home instead of at the study site. There will also be 6 scheduled telephone calls approximately every 2 months.
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Detailed Description
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Conditions
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Study Design
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NA
SINGLE_GROUP
TREATMENT
NONE
Study Groups
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marstacimab (PF-06741086)
Weekly subcutaneous injections.
marstacimab
marstacimab
Interventions
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marstacimab
marstacimab
Other Intervention Names
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Eligibility Criteria
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Inclusion Criteria
* Participants aged 12 to 17 years must be at least 25 kgs at time of consent.
* Participants aged 6 to 11 years must be at least 19 kgs at time of consent.
* Minimum weight requirement for participants aged 1 to 5 years is to be determined.
* Participants with a diagnosis of severe hemophilia A or moderately severe to severe hemophilia B
* Participants must have at least 1 year of diary and/or medical records available in which exogenous FVIII or FIX replacement or bypass agent infusions and hemophilic bleeding episodes were consistently documented over the 12 months prior to the time of consent.
Participants who are enrolled into the Non-Inhibitor Cohort must also meet the following criteria:
* No current detectable inhibitor and no documented history of inhibitors in the 5 years prior to consent
* Must have at least 50 exposure days to FVIII/FIX replacement products
* Must be at least 80% compliant with a stable and effective routine prophylaxis regimen with FVIII/FIX replacement products, for at least 12 months prior to consent
Participants who are enrolled into the Inhibitor Cohort must also meet the following criteria:
* Documentation of current high titer inhibitor (≥5 BU/mL); or current low titer inhibitor (\<5 BU/mL) refractory to FVIII or FIX replacement and with FVIII or FIX recovery \<60% of expected within previous 12 months prior to the time of consent
* Participants who have documented inhibitors while on factor-replacement therapy but who do not meet the high quantitative inhibitor criteria described in the prior bullet at the time of screening (eg, participant with a previously documented high-titer inhibitor ≥5 BU/mL) and whose condition precludes re-challenge with FVIII or FIX replacement may be considered for eligibility on a case-by-case basis with discussion and agreement from the Pfizer medical monitor.
* Hemophilia A participants with on-demand treatment regimen with ≥12 bleeding episodes or hemophilia B participants with on-demand treatment regimen with ≥8 bleeding episodes (spontaneous or traumatic) necessitating treatment with bypass factor in the 12 months prior to informed consent
* Participants must be on an on-demand bypass treatment regimen during the 12 months prior to informed consent
Exclusion Criteria
* Known planned surgical procedure during the planned study period
* Known hemostatic defect other than hemophilia A or B
* Abnormal hematology, renal or hepatic function laboratory results at screening
* Other acute or chronic medical or psychiatric condition that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator
* Individuals with known allergic reaction or hypersensitivity to hamster protein or other components of the study intervention
* Current routine prophylaxis with bypassing agent, non-coagulation non-factor replacement therapy (eg, emicizumab), or any previous treatment with a gene therapy product for treatment of hemophilia
* Participants with inhibitors who are being treated using a prophylaxis treatment regimen with a bypass agent, and, participants who have previously received non-factor-based hemophilia therapy (eg, fitusiran, concizumab, emicizumab) will be considered on a case-by-case basis, only after discussion and agreement between the investigator and the Pfizer medical monitor
* Regular use of immunomodulatory medications (eg, IVIG, routine systemic corticosteroids, rituximab)
* Use of systemic antifibrinolytics, medications that may increase the risk of bleeding, and certain non-steroidal anti-inflammatory drugs within 120 hours of first dose of study intervention and while on study
* Ongoing or planned use of ITI, or prophylaxis with FVIII or FIX replacement at any time after initiation of treatment with study intervention
* Participation in other studies involving investigational drug(s) or investigational vaccine(s) within 30 days (or as determined by local requirements) or 5 half-lives prior to study entry or during study participation
* Previous exposure to marstacimab during participation in other marstacimab clinical studies
* CD4 cell count ≤200/uL if HIV-positive
* Abnormal ECG of clinical relevance that may affect participant safety or interpretation of study results
* Investigator site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members
1 Year
17 Years
MALE
No
Sponsors
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Pfizer
INDUSTRY
Responsible Party
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Principal Investigators
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Pfizer CT.gov Call Center
Role: STUDY_DIRECTOR
Pfizer
Locations
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Intermountain - Primary Children's Hospital
Salt Lake City, Utah, United States
Arbesu Hematología
Mendoza, , Argentina
Sydney Children's Hospital
Randwick, New South Wales, Australia
Royal Children's Hospital
Melbourne, Victoria, Australia
Medizinische Universität Wien
Vienna, Vienna, Austria
HEMOES
Vitória, Espírito Santo, Brazil
Stollery Children's Hospital
Edmonton, Alberta, Canada
Hamilton Health Sciences - McMaster University Medical Centre
Hamilton, Ontario/canada, Canada
Beijing Children's hospital, Capital Medical University
Beijing, Beijing Municipality, China
Southern Medical University Nanfang Hospital
Guangzhou, Guangdong, China
The Affiliated Hospital of Guizhou Medical University
Guiyang, Guizhou, China
Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology
Wuhan, Hubei, China
Tongji Hospital of Tongji Medical College of HUST/Pediatric Hematology Department Pharmacy
Wuhan, Hubei, China
Jiangxi Provincial People's Hospital
Nanchang, Jiangxi, China
Institute of hematology&blood disease hospital
Tianjin, Tianjin Municipality, China
Detska nemocnice FN Brno
Brno, Brno-město, Czechia
Rigshospitalet
Copenhagen, Capital Region, Denmark
Aarhus Universitetshospital, Skejby
Aarhus, Central Jutland, Denmark
Hôpital Universitaire Necker Enfants Malades
Paris, , France
Charité Campus Virchow-Klinikum
Berlin, , Germany
Nirmal Hospital Pvt Ltd.
Surat, Gujarat, India
K.J. Somaiya Hospital
Mumbai, Maharashtra, India
Nil Ratan Sircar Medical College and Hospital
Kolkata, West Bengal, India
Sheba Medical Center
Ramat Gan, Central District, Israel
IRCCS Istituto Giannina Gaslini
Genoa, Liguria, Italy
Istituto Clinico Humanitas
Rozzano, Milano, Italy
Ospedale Pediatrico Bambino Gesù IRCCS
Rome, ROMA, Italy
Azienda Ospedaliero Universitaria di Parma
Parma, , Italy
Azienda Ospedaliero-Universitaria Città della Salute e della Scienza di Torino
Torino, , Italy
Hyogo prefectural Kobe Children's Hospital
Kobe, Hyōgo, Japan
Nagano Children's Hospital
Azumino, Nagano, Japan
Nara Medical University Hospital
Kashihara, Nara, Japan
Saitama Prefectural Children's Medical Center
Saitama-shi, Saitama, Japan
Saga University Hospital
Saga, , Japan
Arké SMO S.A de C.V
Veracruz, , Mexico
King Fahad Specialist Hospital - Dammam
Dammam, Eastern Province, Saudi Arabia
King Faisal Specialist Hospital & Research Center
An Narjis, , Saudi Arabia
Detska fakultna nemocnica Kosice
Košice, , Slovakia
Univerzitna nemocnica Martin
Martin, , Slovakia
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Kyung Hee University Hospital at Gangdong
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Hospital Universitario La Paz
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Changhua Christian Hospital
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National Taiwan University Hospital
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Istanbul Universitesi Istanbul Tıp Fakultesi Hastanesi
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Countries
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Central Contacts
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Related Links
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To obtain contact information for a study center near you, click here.
Other Identifiers
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ANTI-TFPI PEDIATRIC STUDY
Identifier Type: OTHER
Identifier Source: secondary_id
2022-500495-65-00
Identifier Type: REGISTRY
Identifier Source: secondary_id
B7841008
Identifier Type: -
Identifier Source: org_study_id
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