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. It is only recommended if the conditions in the managed access agreement for etranacogene dezaparvovec are followed.
Why the committee made this recommendation
People with moderately severe or severe haemophilia B without anti‑FIX antibodies usually have long-term treatment with FIX concentrates to prevent bleeding episodes (FIX prophylaxis) and on‑demand FIX concentrates to stop bleeding during a bleeding episode. A few people with the condition choose to only have on‑demand treatment.
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.
An indirect comparison of etranacogene dezaparvovec with FIX prophylaxis suggests that it improves bleeding outcomes. But these results are highly uncertain because of differences in the methods used in the studies and the definition and measurement of bleeding outcomes.
Etranacogene dezaparvovec has the potential to be cost effective compared with FIX prophylaxis. But the cost-effectiveness estimates are highly uncertain because of the uncertainty in how long the treatment effect will last. So, etranacogene dezaparvovec is not recommended for routine use in the NHS.
Collecting more data through a managed access agreement may resolve the uncertainty in the evidence. So, etranacogene dezaparvovec is recommended for use with managed access.