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Using SEVENFACT® to treat bleeding in hemophilia patients with inhibitors

Safety of SEVENFACT® for the Treatment of Bleeding Events in Patients With Hemophilia A or B With Inhibitors

PHASE4 · American Thrombosis and Hemostasis Network · NCT04647227

This study is testing if SEVENFACT® can safely help people aged 12 and older with hemophilia who have inhibitors stop bleeding during episodes.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment55 (estimated)
Ages12 Years to 100 Years
SexAll
SponsorAmerican Thrombosis and Hemostasis Network (network)
Drugs / interventionsemicizumab
Locations21 sites (Phoenix, Arizona and 20 other locations)
Trial IDNCT04647227 on ClinicalTrials.gov

What this trial studies

This is a Phase IV, multi-center, open-label safety study evaluating the use of SEVENFACT® in treating bleeding episodes in patients aged 12 and older with Hemophilia A or B who have inhibitors. Participants may be on long-term prophylactic treatment or not, and the study aims to assess the safety of SEVENFACT® in controlling breakthrough bleeding events. The study will follow participants longitudinally for up to four years, with a target enrollment of 28 to 55 participants across multiple sites in the U.S.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 12 and older diagnosed with Hemophilia A or B with inhibitors, either on prophylactic treatment or at risk of breakthrough bleeding.

Not a fit: Patients with additional bleeding disorders or known hypersensitivity to SEVENFACT® or its components may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new effective treatment option for managing bleeding events in hemophilia patients with inhibitors.

How similar studies have performed: Other studies have shown promise in using similar approaches for treating bleeding events in hemophilia, but this specific application of SEVENFACT® is being evaluated for the first time.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. Have a diagnosis of hemophilia A or B with inhibitors.
2. Be 12 years of age and older
3. Be capable of understanding and willing to comply with the conditions of the protocol or have a legal guardian who is capable of understanding and complying with the conditions of the protocol
4. Have read, understood, and documented written informed consent/assent
5. Be able to provide medical evidence through prior medical history of previous inhibitor levels
6. Be willing and able to use the ATHN mobile application or a paper diary to document BEs and medication usage

Exclusion Criteria:

1. Have a disorder of hemostasis in addition to Hemophilia A or B
2. Have a known or suspected intolerance or hypersensitivity to SEVENFACT® or its ingredients
3. Have a known allergy or hypersensitivity to rabbits or rabbit proteins
4. Are receiving prophylactic treatment for bleeding with a drug or biologic that is not approved for this use by the FDA
5. Have had implantation of an investigational medical device within the prior 6 months
6. Have received an investigational drug within 30 days of the baseline visit
7. Have an elective surgical procedure planned during the duration of their participation in the study\*
8. Have any life-threatening disease, or other disease or condition which, in the investigator's judgment, could pose a potential hazard to the patient or interfere with study participation or study outcome (e.g., a history of non responsiveness to bypassing products or thromboembolic disease)

   * Should a participant require an unplanned surgery, the participant will not be withdrawn from the study unless the investigator deems it necessary. Instead, the participant will receive standard of care treatment as determined by the attending physician. If the participant is not withdrawn from the study, the participant's participation in the study will be paused until the investigator feels it is safe for them to continue.

Where this trial is running

Phoenix, Arizona and 20 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Hemophilia A With Inhibitor, Hemophilia B With Inhibitor, Hemophilia A, Hemophilia B, bleeding event, prophylactic treatment

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.