WHAT IS HEMGENIX®?

HEMGENIX® is a gene therapy that aims to give your liver the instructions it needs to make its own working FIX (Factor IX). This allows the liver to produce the FIX protein and raise the levels of working FIX in the blood, helping the blood to clot more normally and prevent or reduce bleeding episodes. The goal of HEMGENIX® is to reduce bleeding and reduce or eliminate the need for routine FIX prophylaxis.^1–3

HEMGENIX® is approved in the UK for the treatment of adults with severe or moderately severe haemophilia B (congenital Factor IX deficiency) who do not have FIX inhibitors (proteins made by the body that stop FIX from working).^1,4

The HOPE-B clinical study followed 54 patients for 5 years after treatment.⁵ Data collected highlighted that the majority of people in the trial had higher FIX levels and fewer bleeds, compared with when they were receiving regular FIX infusions.⁵ More time and clinical evidence is needed to determine how long the effects will last.

While there have been advances in haemophilia B treatment, the usual treatment pathway is lifelong infusions of FIX replacement therapy.⁶

The aim of FIX prophylaxis is to reduce bleeding events by increasing FIX levels. However, the levels of plasma FIX can go up and down, which may put the patient at higher risk of breakthrough bleeds.⁷

Recurring spontaneous bleeding into the joints is the most common bleeding type, and can lead to:^8–10

Joint damage

Pain

Reduced quality of life

Quality of life is often impacted by long-term joint damage, which can cause:¹¹

Chronic pain and discomfort
Restricted mobility and/or disability, such as joint deformity and early-onset arthritis (pain and swelling in the joints)
An inability to perform everyday activities, which may result in anxiety and depression

Key facts about gene therapy:^1,12

Gene therapy is not a cure for haemophilia B

Gene therapy does not change your genes

Gene therapy does not change the genes that you pass on to your children

The virus used in gene therapy will not make you ill

Gene therapy may affect intimacy with your partner

Gene therapy will affect immediate plans for children

You will still need to visit your haemophilia treatment centre after gene therapy

Some people may experience an allergic reaction during gene therapy infusion

Infusion-related side effects can occur during or shortly after you are given the HEMGENIX® infusion (drip). Your doctor will monitor you during your infusion and for at least 3 hours following infusion. However, these side effects are similar to those you might have with any infusion. They are not necessarily unique to gene therapy
If you experience any side effects or other symptoms during or shortly after the infusion, tell your doctor or nurse immediately
Depending on your symptoms, the infusion may be slowed down or interrupted. If the infusion is interrupted, it can be restarted at a slower rate once the infusion reaction has resolved
Your doctor may also consider prescribing corticosteroids, such as prednisolone or prednisone, to help manage any infusion reactions
For further information, refer to the Potential associated risks page or section 4 of the Patient Information Leaflet

Although every effort has been taken to ensure the accuracy of information on this website, it is not intended to be a substitute for professional medical advice, diagnosis or treatment. If you have any unanswered questions about haemophilia B or your treatment, please speak to your specialist medical team.

For full information on potential side effects, warnings and precautions for use, and monitoring requirements, please read the full HEMGENIX® Patient Information Leaflet.

HOPE-B was a clinical trial that looked at the use of HEMGENIX® in 54 people with haemophilia B.⁵ It ran in Europe, including the UK, and the USA from 2018 to 2025.^6,13

FIX, Factor IX.

How HEMGENIX® works

A gene therapy specifically designed to target haemophilia B

References

1. HEMGENIX® (etranacogene dezaparvovec). Summary of product characteristics. 2. Miesbach W et al. Gene therapy with adeno-associated virus vector 5-human factor IX in adults with hemophilia B. Blood. 2018;131(9):1022–1031. 3. Nathwani AC. Gene therapy for hemophilia. Hematology Am Soc Hematol Educ Program. 2019;2019(1):1–8. 4. National Institute for Health and Care Excellence (NICE). Technology appraisal guidance: Etranacogene dezaparvovec for treating moderately severe or severe haemophilia B. (2024). TA989. Published 24 July 2024. Available at: https://www.nice.org.uk/guidance/ta989. Accessed September 2026. 5. Pipe SW et al. Final Analysis of a Study of Etranacogene Dezaparvovec for Hemophilia B. N Engl J Med. 2026;394(5):463–474. 6. Pipe SW et al. Gene Therapy with Etranacogene Dezaparvovec for Hemophilia B. N Engl J Med. 2023;388(8):706–718. 7. Shapiro AD et al. Recombinant factor IX-Fc fusion protein (rFIXFc) demonstrates safety and prolonged activity in phase 1/2a study in hemophilia B patients. Blood. 2012;119(3):666–672. 8. Mulder K, Llinás A. The target joint. Haemophilia. 2004;10(Suppl 4):152–156. 9. Jiménez-Yuste V et al. Joint status in Spanish haemophilia B patients assessed using the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score. Haemophilia. 2019;25(1):144–153. 10. Schnohr C et al. Joint Mobility and Physical Function of Danish Hemophilia Patients: A Three-Wave Panel Study Spanning 24 Years. Acta Haematol. 2018;140(4):240–246. 11. O’Hara J et al. The impact of severe haemophilia and the presence of target joints on health-related quality-of-life. Health Qual Life Outcomes. 2018;16(1):84. 12. CSL Behring, Haemophilia Society. 2026. BEYOND Gene Therapy for Haemophilia B: An introduction. 13. ClinicalTrials.gov. HOPE-B: Trial of AMT-061 in Severe or Moderately Severe Hemophilia B Patients (NCT03569891). Available at: https://clinicaltrials.gov/study/NCT03569891. Accessed September 2026.

Reporting side effects
If you experience any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in the package leaflet. You can also report side effects directly via the Yellow Card Scheme. By reporting side effects, you can help provide more information on the safety of this medicine. Adverse events should also be reported to CSL Behring UK Ltd on 01444 447 405 or at medinfo@cslbehring.com.

▼ This medicine is subject to additional monitoring. This will allow quick identification of new safety information. You can help by reporting any side effects you may get. See above for how to report side effects.