For Healthcare Professionals

Open-Label Single Ascending Dose of Adeno-associated Virus Serotype 8 Factor IX Gene Therapy in Adults With Hemophilia B


About the study

The purpose of this study is to evaluate the safety of single ascending IV doses of a Factor IX (FIX) Gene Therapy in up to 16 Adults with Hemophilia B.

Who can take part

You may be eligible to participate in the study if you meet the following criteria:


  1. Males age 18-75 years, inclusive
  2. Established hemophilia B with ≥3 hemorrhages per year requiring treatment with exogenous FIX OR use of FIX prophylaxis because of history of frequent bleeding episodes
  3. Plasma FIX activity ≤2% (<1% for first cohort; then per protocol)
  4. Negative for active Hepatitis C virus (HCV), defined as Hepatitis C virus antibody negative and negative (undetectable) PCR test for plasma Hepatitis C virus ribonucleic acid (RNA) OR if Hepatitis C virus antibody positive must have ≥2 consecutive negative (undetectable) PCR tests for plasma HCV RNA at least 3 months apart, and negative at screening


  1. Family history of inhibitor to FIX protein or personal laboratory evidence of having developed inhibitors to FIX protein at any time (>0.6 Bethesda Units on any single test)
  2. Documented prior allergic reaction to any FIX product
  3. Detectable AAV8 neutralizing antibodies
  4. Markers of hepatic inflammation or overt or occult cirrhosis as evidenced by one or more of the following:
  5. Platelet count <175,000/μL
  6. Albumin ≤3.5 g/dL
  7. Total bilirubin >1.5 x ULN and direct bilirubin ≥0.5 mg/dL
  8. Alkaline phosphatase >2.0 x ULN
  9. ALT or AST >2.0 x ULN (except for subjects who are HIV infected)
  10. Liver biopsy in the past indicating moderate or severe fibrosis (Metavir staging of 2 or greater)
  11. History of ascites, varices, variceal hemorrhage or hepatic encephalopathy
pin location

Study Locations

Enter your ZIP code/Postal code/PIN code to locate study sites near you:

How to Apply

Contact the study center to learn if this study is a good match for you.
Email iconEmail Study Center

Study’s details


Hemophilia B




Phase 1/Phase 2

Participants needed


Est. Completion Date

Oct 2030

Treatment type



Takeda identifier


Study number


Understanding Clinical Trials

Get answers to your questions about clinical trials.What is a clinical research?What does taking part in clinical trials involve?What should I ask the trial doctor?


Sign up to save your favorites, 
receive newsletters, resources, and alerts 
about clinical trials related to your conditions of interest.