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Open-Label Extension Study of Marstacimab in Hemophilia Participants With or Without Inhibitors
NCT05145127 · View on ClinicalTrials.gov ↗
Study Summary
Study B7841007 is an open-label extension study to assess the long-term safety, tolerability, and efficacy of prophylaxis treatment with marstacimab in participants who did not require "Early Termination" from the Phase 3 Study B7841005 and from the Phase 3 Study B7841008. Study B7841005: approximately 145 adolescent and adult participants 12 to \<75 years of age with severe hemophilia A or moderately severe to severe hemophilia B (defined as FVIII activity \<1% or FIX activity ≤2%, respectively) with or without inhibitors are expected to be enrolled in Study B7841005 during which they will receive prophylaxis (defined as treatment by SC injection of marstacimab). Study B7841008: this is an ongoing Phase 3, open-label study in pediatric participants \<18 years of age with severe hemophilia A (FVIII Coagulation Factor Activity \<1%) or moderately severe to severe hemophilia B (FIX Coagulation Factor Activity ≤2%). A sequential approach will be used in enrolling at least 100 pediatric participants, at least 20 of which will be aged ≥12 to \<18 years and at least 80 participants will be aged ≥1 to \<12 years. At the start of study B7841008, the dosing and data available in adolescent and adult participants in Study B7841005 supported the initiation of B7841008 study in participants aged ≥12 to \<18 years. Subsequently, additional safety and efficacy data from adolescent participants in Study B7841005 became available for benefit/risk assessment in support of dosing participants aged ≥6 to \<12 years. Based on the positive benefit/risk assessment conducted by both internal Pfizer review and eDMC review, dosing of the ≥6 to \<12 years age group was initiated in June 2023 in B7841008 Study. Data from participants ≥6 years from B7841008 Study and Study B7841005 will support the dosing of participants aged ≥1 to \<6 years. All participants will be provided the prefilled pen (PFP) for administration of marstacimab in the study. Use of the prefilled syringe (PFS) will be p
Conditions Studied
Interventions
- DRUG PF-06741086
Study Locations (20)
Other
- Beijing Children's Hospital, Capital Medical University — Beijing
- Klinicki bolnicki centar Zagreb — Zagreb
- Hôpital Universitaire Necker Enfants Malades — Paris
- Prince of Wales Hospital — Hong Kong
- Queen Mary Hospital — Hong Kong
Ontario
- Hamilton Health Sciences - McMaster University Medical Centre — Hamilton
- Hamilton Health Sciences - McMaster University Medical Centre — Hamilton
Guizhou
- The Affiliated Hospital of Guizhou Medical University — Guiyang
- The Affiliated Hospital of Guizhou Medical University — Guiyang
Tianjin Municipality
- Institute of hematology&blood disease hospital — Tianjin
- Institute of hematology&blood disease hospital — Tianjin
Iowa
- University of Iowa — Iowa City
New York
- Northwell Health HTC — New Hyde Park
Washington
- Washington Institute for Coagulation d/b/a WACBD — Seattle
Victoria
- Royal Children's Hospital — Melbourne
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 245 participants |
| Start Date | 2021-11-17 |
| Est. Completion | 2030-07-31 |
| Phase | Phase 3 |
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Full Details on ClinicalTrials.gov ↗What the Registry Record Tells You About NCT05145127
The ClinicalTrials.gov registry entry for NCT05145127 describes a study currently listed as recruiting. It is categorized as Phase 3, which is the standard way researchers label where a study sits along the investigational pathway from early safety work through later efficacy and post-marketing evaluation. The registered enrollment target is 245 participants, a figure that helps gauge the scale of data the investigators plan to collect. The listed sponsor is Pfizer, which has 769 total studies on file at ClinicalTrials.gov, and sponsors are the parties responsible for study design, oversight, and regulatory filings.
The record links to 2 conditions, with Hemophilia A appearing as the primary indexed condition, and to 1 intervention — of which PF-06741086 is the first listed. Interventions can include drugs, devices, procedures, behavioral programs, or observational arms, and each is tracked as a separate registry field so that downstream queries can filter accurately. When a trial lists multiple interventions, it usually reflects a multi-arm design or a comparison protocol rather than a single treatment being tested in isolation. The brief summary published in the registry is the clearest source of protocol intent and should be read before drawing conclusions from any sidebar tags.
Geographic footprint matters for practical reasons: NCT05145127 reports 20 study locations spanning 13 distinct geographic areas — top geographies include Other, Ontario, Guizhou. A larger site network tends to correlate with broader recruitment capacity, but it does not imply anything about study quality, and site-level enrollment status can diverge from the overall registry status shown above. Every data point on this page comes from the public ClinicalTrials.gov dataset and is reproduced here for reference only; it is not a medical recommendation, an endorsement of the sponsor, or an invitation to enroll. Verify current status, eligibility criteria, and contact details directly at ClinicalTrials.gov, and discuss any participation decision with your own healthcare provider.
Frequently Asked Questions
What is clinical trial NCT05145127 about?
NCT05145127 is a clinical study titled "Open-Label Extension Study of Marstacimab in Hemophilia Participants With or Without Inhibitors". Study B7841007 is an open-label extension study to assess the long-term safety, tolerability, and efficacy of prophylaxis treatment with marstacimab in participants who did not require "Early Termination" from the Phase 3 Study B7841005 and from the Phase 3 Study B7841008. Study B7841005: approxima...
What is the current status of trial NCT05145127?
This trial is currently recruiting. It is a Phase 3 study. The enrollment target is 245 participants. The study started on 2021-11-17. Estimated completion is 2030-07-31.
What conditions does trial NCT05145127 study?
This clinical trial studies the following conditions: Hemophilia A, Hemophilia B. These conditions were identified from the trial registry and reflect the primary focus areas of the research.
What interventions are being tested in trial NCT05145127?
The interventions under investigation include: PF-06741086 (DRUG). Each intervention is being evaluated for safety and efficacy as part of this clinical study.
Who is sponsoring clinical trial NCT05145127?
This trial is sponsored by Pfizer, which has 769 total clinical trials registered on ClinicalTrials.gov. The sponsor is responsible for the study's design, funding, and regulatory compliance.
Where is trial NCT05145127 being conducted?
This trial has 20 study locations across Iowa, New York, Washington, Victoria, Alberta. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
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