This is not an interventional trial but an observational, post-authorization, long-term follow-up cohort study. It investigates the short- and long-term effectiveness and safety of HEMGENIX (etranacogene dezaparvovec) in patients with hemophilia B. A comparison cohort of hemophilia B patients treated with FIX prophylaxis is also included; the HEMGENIX cohort requires treatment with commercial HEMGENIX and signed informed consent within the specified time windows.
The summary above is a plain-language rendering of the official record. The original English title is shown for reference.
Criteria are reproduced from the ClinicalTrials.gov record in the original English. Only the trial team can determine eligibility.
Inclusion Criteria: * HEMGENIX Cohort: * \- Treatment with commercial HEMGENIX. * \- Have provided signed written informed consent within 3 months before or within 6 months after HEMGENIX treatment, or within 6 months of when the study is initiated at the participating site. * FIX Prophylaxis Cohort: * \- Adult patients (≥ 18 years) with hemophilia B who have consented and enrolled in ATHN Transcends Hemophilia Cohort (or a similar registry) and are receiving FIX prophylaxis therapy. Exclusion Criteria: * HEMGENIX Cohort: * \- The patient population that will be observed in this study must not have been treated with etranacogene dezaparvovec in a clinical trial.