What is it prescribed for?
BEQVEZ is prescribed for adults with moderate to severe hemophilia B, a rare inherited bleeding disorder caused by low levels of clotting factor IX. People with hemophilia B can experience serious bleeding episodes, including bleeding into joints, muscles, and internal organs. Many patients require regular factor IX infusions throughout their lives to prevent dangerous bleeding. BEQVEZ is important because it is a one-time gene therapy designed to help the body produce its own factor IX instead of relying on ongoing replacement therapy. This treatment offers a new long-term approach for eligible patients with hemophilia B. The FDA approved BEQVEZ on May 13, 2026.
What is the name of the drug and what does it do?
The medication is BEQVEZ™ (fidanacogene elaparvovec-dzkt), an intravenous gene therapy. It delivers a working copy of the gene needed to make factor IX, the clotting protein missing in people with hemophilia B. After treatment, the liver begins producing factor IX on its own, which can help reduce or prevent bleeding episodes. BEQVEZ is intended as a one-time treatment rather than a chronic therapy.
How does it work?
BEQVEZ uses a modified adeno-associated virus (AAV) vector to carry a healthy factor IX gene into liver cells. Once inside the liver, the new gene helps the body make functional factor IX protein.
This process helps:
- Increase factor IX activity in the bloodstream
- Reduce spontaneous bleeding episodes
- Lower the need for routine factor IX infusions
Because the therapy changes how the body produces clotting factor, careful patient selection and monitoring are required.
What did the research discover?
Clinical studies showed that many patients receiving BEQVEZ achieved sustained increases in factor IX levels. Researchers observed major reductions in annual bleeding rates compared with prior treatment periods.
Studies found:
- Fewer spontaneous bleeding episodes
- Reduced use of preventive factor IX therapy
- Long-lasting increases in factor IX activity in many patients
Some patients were able to stop routine prophylactic factor IX infusions after treatment. These findings supported FDA approval as an important advance in hemophilia B care.
What are some of the side effects?
The most common side effects included:
- Elevated liver enzymes
- Headache
- Flu-like symptoms
- Fatigue
- Infusion-related reactions
More serious risks may include immune reactions against the therapy or liver inflammation. Because of this, patients require regular liver function testing and close follow-up after treatment.
What are the dosage recommendations and how is it prescribed?
BEQVEZ is given as a one-time intravenous infusion in a specialized treatment center under the supervision of physicians experienced in hemophilia care. Before treatment, patients must undergo testing to confirm eligibility, including testing for antibodies against the viral vector used in the therapy.
Doctors monitor:
- Factor IX levels
- Liver function tests
- Signs of immune reactions
- Bleeding frequency after treatment
Patients may also receive corticosteroids if liver enzyme levels rise following infusion. Long-term monitoring is required after gene therapy treatment.
Source:
BEQVEZ™ (fidanacogene elaparvovec-dzkt) suspension, for intravenous infusion [prescribing information]. Silver Spring (MD): U.S. Food and Drug Administration; 2026. Available from: https://www.fda.gov/media/178140/download. Accessed by: June 6, 2026.
