NHS treats first haemophilia B patient with gene therapy

The first haemophilia B patient has been treated with gene therapy on the NHS.

The patient is a 44-year-old man from Newcastle who had been diagnosed with Haemophilia B at 18 months old. He received a single dose of Hemgenix (also known as etranacogene dezaparvovec) administered through an hour-long infusion at Guy's and St Thomas' Hospital in London.

'This is a big step forward in our ability to manage haemophilia B and could change the lives of some of our patients,' said consultant haematologist Dr Pu-Lin Luo, who was part of the team administering the treatment. 'It is also a testament to the advancement of cell and gene therapies in the UK, and these are exciting times.'

Haemophilia is a group of inherited disorders where proteins necessary for blood to clot do not work correctly, leading to episodes of uncontrolled bleeding, even from minor injuries. Haemophilia B, where the gene encoding clotting factor IX is faulty, affects around 2000 people in the UK.

Hemgenix contains a non-infectious viral vector that delivers a functioning copy of the gene into liver cells, allowing recipients to make a functioning version of the clotting factor IX protein. It is the most expensive drug available via the NHS, with a list price of £2.6 million per dose, although the NHS has arranged an undisclosed discount with the manufacturer.

However, the standard treatment for Haemophilia B involves regular blood infusions every 3 to 21 days, estimated to cost around £8 million over a patient's lifetime, so if gene therapy can provide a permanent cure, the cost savings could be considerable. Only a single dose is needed, followed by regular check-ups of the patient's liver function.

During clinical trials, patients administered the drug experienced a 38.6 per cent increase in their factor IX activity levels after 3 years, following a single dose, accompanied by a 64 per cent reduction in the adjusted bleeding rate between 12 and 18 months.

'The current treatment of lifelong intravenous injections can place a significant burden on those living with haemophilia and has an impact on broader family, relationships and work. The availability of gene therapy for haemophilia B as a one-time infusion will allow those eligible for treatment to expand their horizons and live life to the full, free from the restrictions of regular injections,' said Kate Burt, chief executive of the Haemophilia Society.

Hemgenix was approved in 2024 by the NHS England's National Innovative Medicines Fund, for use in patients with severe to moderately severe Haemophilia B who have not taken antibodies targeting clotting factors, making around 260 people eligible in the UK (see BioNews 1245).