Testing a bleeding treatment for hemophilia patients with inhibitors

Plain-English translation of NCT04647227 on ClinicalTrials.gov ↗ · Source last updated January 2026 · Translation generated June 2026 · How we translate trials

Phase 4 — The treatment has already been approved. Researchers are tracking how it works in a large number of people over time.

What is this trial?

This is a safety study of SEVENFACT®, a medication designed to stop bleeding episodes in people with hemophilia A or B who have inhibitors. Inhibitors are antibodies that make standard hemophilia treatments less effective, so patients need alternative options. This study will follow people using the medication to make sure it works safely, whether or not they are also taking other preventive treatments.

While this medication has already been approved by the FDA, researchers want to learn more about how safely and effectively it works in real-world use, especially in patients who are on other preventive therapies or managing bleeds on their own.

Do you qualify?

You likely qualify if…

you have been diagnosed with hemophilia A or B with inhibitors and have proof of previous inhibitor levels
you are 12 years of age or older
you are willing to use a mobile app or paper diary to track bleeding episodes and medication use
you are able to understand the study and follow its requirements, or have a legal guardian who can do so
you have read and signed an informed consent form showing you understand the study

You likely don't qualify if…

you have a bleeding disorder in addition to hemophilia A or B
you have a known allergy or sensitivity to this medication or its ingredients, including rabbit proteins
you are taking a preventive bleeding medication that has not been approved by the FDA
you have received an experimental drug within the past 30 days or had an experimental medical device implanted within the past 6 months
you have a serious medical condition or history of not responding to similar bleeding treatments that might make the study unsafe for you

What participation looks like

You would be enrolled for up to 4 years and receive nine doses of the medication (enough for nine potential bleeding episodes). When a bleeding episode occurs, you would either give yourself the injection at home following your doctor's guidance, or receive it at a treatment facility. You would track all bleeding episodes and medication use through a mobile app or paper diary, and the research team would monitor your safety throughout the study.

AI-generated summary from trial data · Jun 3, 2026 · Not medical advice

Trial locations(21 sites)

United States

Arizona Hemophilia and Thrombosis Center at Phoenix Children's Hospital, Phoenix, Arizona

Arkansas Center for Bleeding Disorders, Little Rock, Arkansas

Orthopaedic Institute for Children, Los Angeles, California

University of California at Davis UC Davis Hemostasis and Thrombosis Center, Sacramento, California

Children's National Hemophilia Center, Washington D.C., District of Columbia