etranacogene dezaparvovec for haemophila B

Etranacogene dezaparvovec is a form of gene therapy for people living with hemophilia B (1,2)

• haemophilia B [factor IX (FIX) deficiency] is an X-linked inherited bleeding disorder that affects 25,000 people globally
• severity is classified as:
  • severe <1% factor activity
  • moderate 1-5% factor activity
  • mild 6-40% factor activity
  • bleeding complications are most significant in patients with moderate-to-severe hemophilia B (FIX <= 2%) and include traumatic and spontaneous bleeding into joints and muscle
• etranacogene dezaparvovec is a form of gene therapy that includes a modified form of FIX (FIX Padua) which produces high levels of FIX activity compared with normal FIX (1)
• evidence from a clinical trial suggests that the gene therapy etranacogene dezaparvovec reduces the number of bleeding episodes a person has each year. But there is not enough evidence on how well it works in the long term (2)
• an indirect comparison of etranacogene dezaparvovec with FIX prophylaxis suggests that it improves bleeding outcomes

NICE state that (2)

• etranacogene dezaparvovec is recommended with managed access as an option for treating moderately severe or severe haemophilia B (congenital factor IX [FIX] deficiency) in adults without anti‑FIX antibodies

Reference:

1. Thornburg CD. Etranacogene dezaparvovec for hemophilia B gene therapy. Ther Adv Rare Dis. 2021 Nov 24;2:26330040211058896. doi: 10.1177/26330040211058896
2. NICE (July 2024). Etranacogene dezaparvovec for treating moderately severe or severe haemophilia B