What the trial was testing
The trial enrolled 3 patients with hemophilia b. The study was sponsored by CSL Behring and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was initial testing (phase 2). Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
Factor IX rose to 47% of normal — and bleeding stopped completely.
Blood Advances · 2019 · NCT03489291
These findings — that factor IX activity at 26 weeks and complete bleed cessation after gene therapy — were published in the Blood Advances and represent the headline result of the study.
Researchers tracked outcomes across 3 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with hemophilia b, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Etranacogene dezaparvovec (Hemgenix) is FDA-approved and available now for hemophilia B in adults. It is a one-time IV infusion that can replace lifelong factor IX prophylaxis for many patients. The drug list price is the highest of any U.S. medicine ($3.5 million), but most major insurers cover it. Ask a hemophilia center about eligibility.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open hemophilia b trials
A Study to Investigate the Safety and Effectiveness of a Coagulation Factor IX Gene Insertion Therapy (REGV131-LNP1265) in Pediatric, Adolescent and Adult Participants With Hemophilia B
Participants in this study have a genetic mutation, specifically in the coagulation (blood clotting) Factor 9 gene that causes severe or moderately severe hemophilia B. This study is researching an experimental gene insertion therapy (the adding of a gene into your DNA) called REGV131-LNP1265, also called the "study drug". Gene insertion therapy aims to teach the body how to produce clotting factor long-term, without the need for factor replacement therapy. The main aim of this study is to find a safe and well-tolerated dose of the study drug by checking the side effects that may happen from taking it, both in the near term and over time. The study is looking at several other research questions including: * How much study drug is in the blood at different times * Whether the body makes antibodies against parts of the study drug, which could make the drug less effective or could lead to side effects. Antibodies are proteins produced by the body's immune system in response to a foreign substance * Whether the body makes antibodies against the clotting factor replacement therapy * How often factor replacement therapy is needed, both on a regular basis for prevention of bleeding, and as needed to treat bleeding events (and it if changes after taking study drug) * Whether there is a difference in 2 different methods for measuring Factor 9 activity in the blood
SAFE Study: Safety of aPCC Following Emicizumab Prophylaxis
The purpose of the aPCC-emicizumab safety study is to investigate the hemostatic efficacy as measured by thrombin generation, of a low personalized dose of aPCC (FEIBA) in children and adults with hemophilia A and inhibitors on emicizumab prophylaxis.