NCT06008938 · CSL Behring
An Observational Cohort Study to Characterize the Effectiveness and Safety of HEMGENIX® in Patients With Hemophilia B
(IX-TEND 4001)
What this study is about
This observational, post-authorization, long-term follow-up study aims to investigate the short and long-term effectiveness and safety of HEMGENIX in patients with hemophilia B. The study will also include a group of participants of patients with hemophilia B treated with FIX prophylaxis to enable interpretation of relevant effectiveness and safety findings of HEMGENIX.
View original scientific description
This observational, post-authorization, long-term follow-up study aims to investigate the short and long-term effectiveness and safety of HEMGENIX in patients with hemophilia B. The study will also include a cohort of patients with hemophilia B treated with FIX prophylaxis to enable interpretation of relevant efficacy and safety findings of HEMGENIX.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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.
Where
- Rochester, New York
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Feb 19, 2026 · Source of record for eligibility and locations