A Study to Learn About How Changing Therapy From Emicizumab to Marstacimab Affects People With the Severe Hemophilia A.
Public ClinicalTrials.gov record NCT06703606. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A PHASE 1B OPEN-LABEL NON-RANDOMIZED STUDY TO ASSESS THE SAFETY, PHARMACOKINETICS, AND PHARMACODYNAMICS OF MARSTACIMAB TREATMENT FOLLOWING THE DISCONTINUATION OF EMICIZUMAB THERAPY IN ADOLESCENT AND ADULT PARTICIPANTS WITH SEVERE HEMOPHILIA A WITHOUT INHIBITORS.
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
The purpose of the study is to learn about safety, how the body processes marstacimab and how it works in patients with severe hemophilia A without inhibitors. Hemophilia A is rare bleeding disorder where the blood doesn't clot normally. This causes a person to bleed a lot, even from a small cut. These patients who are on emicizumab medicine for routine prophylaxis for at least 6 months, and desire to switch to marstacimab medicine. Inhibitors are antibodies that the immune system develops because it sees the infused clotting factor as a foreign substance that needs to be destroyed. Antibodies are proteins that eat up the activated factor before it has time to stop the bleeding. Prophylaxis are preventive medicines. This study is seeking for participants: * with severe Hemophilia A withouth inhibitors who are on emicizumab treatment for at least 6 months. * must be 12 to less than 75 years old * must have a body weight of at least 35 kilograms. The results from this study will serve as a guide to doctors and their hemophilia A patients who will change their medicines in the real-world clinical setting. Patients who can take part in the study will receive marstacimab medicine as weekly injections under the skin of 150 milligrams for 4 months. Study treatment with marstacimab will be initiated no earlier than 14 days after last dose of emicizumab. The study can last up to 6 months. The sponsor will provide marstacimab. Patients will continue their usual treatment with the infused clotting factor for their bleeds when taking part in the study. Roll-over into an optional study treatment extension period will be available to participants who wish to continue prophylaxis with marstacimab in countries where it is not commercially available.
Study identification
- NCT ID
- NCT06703606
- Recruitment status
- Recruiting
- Study type
- Interventional
- Phase
- Phase 1
- Enrollment
- 15 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 12 Years to 74 Years
- Sex
- Male
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- May 12, 2025
- Primary completion
- May 4, 2027
- Completion
- May 4, 2027
- Last update posted
- Jun 2, 2026
2025 – 2027
United States locations
- U.S. sites
- 3
- U.S. states
- 2
- U.S. cities
- 2
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Orthopaedic Institute for Children/Orthopaedic Hemophilia Treatment Center | Los Angeles | California | 90007 | Recruiting |
| Brody School of Medicine at East Carolina University | Greenville | North Carolina | 27834 | Recruiting |
| ECU Health Medical Center | Greenville | North Carolina | 27834 | Recruiting |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
Non-U.S. locations
This page focuses on the U.S. directory. The official record also lists 4 non-U.S. sites.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT06703606, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Jun 2, 2026 · Synced Sep 8, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT06703606 live on ClinicalTrials.gov.