An observational study in Hemophilia A and Hemophilia B, sponsored by St. Jude Children's Research Hospital. Not yet recruiting at 1 site in United States. Open to male participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by St. Jude Children's Research Hospital · Observational
This observational study will obtain liver biopsy samples and evaluate the long-term effect of adeno-associated virus (AAV)-mediated gene therapy on the liver tissue in adult patients with hemophilia A or hemophilia B who have previously been treated with a factor VIII or factor IX gene-containing AAV-vector for liver-targeted gene transfer. Participants are from a cohort of patients treated with AAV-mediated gene transfer and at least 6 months after vector infusion.
This is a prospective cohort study evaluating the effect of AAV-mediated gene therapy on the liver in adult patients with hemophilia A or hemophilia B who have previously been treated with a FVIII/FIX gene-containing AAV-vector for liver-targeted gene transfer.
To better understand the effect of AAV-mediated gene transfer on the liver, eligible participants can allow the use and analysis of already existing liver tissue samples, taken and preserved after having received gene therapy. Alternatively, eligible participants can consent to providing a new liver tissue sample which will be obtained by undergoing a standard transjugular liver biopsy (TJLB) procedure under moderate sedation. . The procedure will be done as outpatient (day 1) with post procedure follow-up on day 2, 3, 4 and 14.
844 studies on the registry are indexed under Hemophilia A; 138 are open to participants now.
This study's planned enrollment of 8 is below the median of 81 across 310 observational studies indexed under Hemophilia A.
Browse Hemophilia A studies →St. Jude Children's Research Hospital is the lead sponsor of 440 studies on the registry; 102 are open to participants now.
Of its 61 completed or terminated interventional studies of FDA-regulated products, 37 (61%) have results posted.
Counted across the registry records on this site, refreshed daily.
Those who meet the Eligibility Criteria.
Inclusion Criteria:
Patients, who were enrolled and treated in one of the following clinical trials:
Exclusion Criteria (Do not apply to participants who will not undergo liver , and have leftover liver tissue from a previous biopsy procedure, because all exclusion criteria only cover the safety considerations for the biopsy procedure.):
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Those who meet the Eligibility Criteria
Procedure: Liver Biopsy
Standard transjugular liver biopsy under moderate sedation
Assessment of the number of hepatocytes transduced with AAV vector genome in liver biopsy samples analyzed by FISH
Fluorescence in situ hybridization (FISH)
Time frame: single time point (day of biopsy)
The degree of hepatocyte damage at a morphological level
Standard and immunohistochemical tissue staining
Time frame: single time point (day of biopsy)
The number and type of hot spots for integration of AAV provirus in liver cells
DNA sequencing
Time frame: single time point (day of biopsy)
The number of hepatocytes revealing FVIII/FIX RNA in-situ transcripts
Assessment of RNA in-situ transcripts
Time frame: single time point (day of biopsy)
The number and types of epigenetic changes within the AAV genome in the liver
DNA methylation analysis and histone association studies
Time frame: single time point (day of biopsy)
The qualitative and quantitative assessment of the RNA transcriptome
Assessment of RNA transcriptome
Time frame: single time point (day of biopsy)
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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