Hemophilia B Clinical Trials and Treatments

Hemophilia B is an X-linked recessive inherited bleeding disorder caused by deficiency or dysfunction of clotting factor IX (Christmas factor). Pathophysiology involves reduced or abnormal factor IX protein affecting the intrinsic tenase complex essential for coagulation amplification. Clinically, hemophilia B is indistinguishable from hemophilia A, with manifestations strictly dependent on factor IX activity levels.

The most common symptoms of Hemophilia B include Easy bruising and bleeding, Hemarthrosis (joint bleeds) causing pain and swelling, Muscle hematomas, Spontaneous bleeding in severe forms, Bleeding after trauma or surgery, among others. Hemophilia B affects approximately 1 in 25,000 to 33,000 males; very rare in females. Symptoms can range from mild to severe and may vary between individuals.

Trial Friend lists all active clinical trials for Hemophilia B from ClinicalTrials.gov, with eligibility criteria translated into plain English. Patients can filter by trial phase and recruitment status, search by location, and use the Match Me tool to score trials against their profile. Factor IX replacement therapy (plasma-derived prothrombin complex concentrate [PCC] containing factors II, VII, IX, X or recombinant factor IX) is the standard treatment, tailored to severity and bleeding event. Recombinant factor IX products with extended half-life through Fc fusion or albumin fusion significantly reduce treatment frequency.

Yes. As of October 14, 2026, 11 FDA-approved medicines have a current label that names Hemophilia B: Alhemo (concizumab), first approved in 2024; Hemgenix (etranacogene dezaparvovec), first approved in 2022; Hympavzi (marstacimab), first approved in 2024; Qfitlia (fitusiran), first approved in 2025; Alprolix (coagulation factor ix (recombinant), fc fusion protein (eftrenonacog alfa)); BeneFIX (coagulation factor ix (recombinant)); Feiba (anti-inhibitor coagulant complex); Idelvion (coagulation factor ix (recombinant), albumin fusion protein (albutrepenonacog alfa)); NovoSeven RT (coagulation factor viia (recombinant) (eptacog alfa)); Profilnine (factor ix complex (human)); and Rebinyn (coagulation factor ix (recombinant), glycopegylated (nonacog beta pegol)). Corticosteroids and immune globulins count once each.

Hemophilia B is caused by variants in the F9 gene. Females with skewed X-inactivation can be symptomatic carriers.

It is X-linked, so it mainly affects boys, and a mother who carries the variant has a 1 in 2 chance of passing it to each son. The condition affects approximately 1 in 25,000 to 33,000 males; very rare in females. Genetic testing confirms the diagnosis.

Yes. Genetic testing for Hemophilia B looks at the F9 gene. Females with skewed X-inactivation can be symptomatic carriers.

It is X-linked, so it mainly affects boys, and a mother who carries the variant has a 1 in 2 chance of passing it to each son.

A confirmed variant establishes the diagnosis and is often required to enroll in gene-specific trials. The labs currently offering the test are listed in the Genetic Testing section of this page, pulled live from the NIH Genetic Testing Registry. A genetic counselor can help interpret the result and decide which relatives should be tested.

Eligibility for Hemophilia B clinical trials depends on factors like age, diagnosis, treatment history, and overall health. Each trial sets its own inclusion and exclusion criteria. Trial Friend translates these requirements from medical language into plain English so patients can review them more easily. The Match Me tool can score your profile against active trials to help identify studies that may be a fit.

Participating in a Hemophilia B clinical trial typically involves scheduled visits, medical tests, and close monitoring by a research team. Depending on the study phase, you may receive an investigational treatment, a placebo, or the current standard of care. Trials may last from a few weeks to several years. Study participation is voluntary, and you can withdraw at any time.