Recruiting

Long-term safety study of a new bleeding prevention treatment for hemophilia A

Plain-English translation of NCT05685238 on ClinicalTrials.gov ↗ · Source last updated June 2026 · Translation generated July 2026 · How we translate trials

Phase 3 — Testing in thousands of people, comparing the treatment against what doctors currently use. This is the last big step before approval.

What is this trial?

This is a long-term study testing a new medicine called designed to help prevent bleeding episodes in people with hemophilia A. The medication works by replacing the function of the clotting factor that is missing in hemophilia A. Researchers want to understand how safe and effective this treatment is when used over many years.

Hemophilia A causes life-threatening or disabling bleeding because the blood lacks an important clotting protein. Some patients also develop inhibitors—antibodies that block standard treatments—making bleeding control even harder. This medication offers a new option to help prevent bleeds and reduce the burden of treatment for these patients.

Do you qualify?

You likely qualify if…

you have been diagnosed with hemophilia A (severe form, with or without inhibitors)
you are under 1 year old at the time you sign up (for Arm 3 only), or you are already participating in one of the earlier related studies (for Arms 1 and 2)
you weigh at least 3.2 kilograms (Arm 3 only)
you have had little to no previous treatment for hemophilia (Arm 3 only)
you are willing to give informed consent and follow the study schedule and procedures

You likely don't qualify if…

you are pregnant, breastfeeding, or planning to become pregnant during the study
you are a woman of childbearing age and not using highly effective contraception
you have a serious medical condition (other than hemophilia A) that might make the study unsafe for you
you have already been enrolled in this particular study before
you plan to have major surgery during the first part of the study

What participation looks like

If you qualify, you will receive injections of the medication under your skin, typically using a pen-injector device, over a period of up to 5.5 years. You will attend regular clinic visits where the research team will monitor how well the treatment is working, track any bleeding episodes, and watch for side effects. You may also be asked to keep a diary and complete other study-related procedures. The study will end when the medication is approved and available in your country, or in June 2028, whichever comes first.

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

Long-term safety study of a new bleeding prevention treatment for hemophilia A

What is this trial?

Do you qualify?

What participation looks like

Trial locations