Advances in gene therapy lead to successful treatment of haemophilia
12 December 2014
Research at the UCL Cancer Institute has produced the first promising results using gene therapy to help patients with haemophilia.
Haemophilia A and B are inherited genetic diseases caused by the absence of or production of a defective protein that prevents blood from clotting properly. Over 3,500 people are affected every year in the UK. Severely affected patients suffer from frequent, often life-threatening, bleeding episodes that occur without any apparent injury.
The standard treatment for the condition is to inject normal versions of the missing clotting proteins every two or three days. This is both onerous and invasive. It is also very expensive (£150,000 per year) meaning it is only available to those patients who live in high-income countries, leaving 80% of the world’s haemophilia patients untreated. Antibodies that destroy the clotting factor before it has a chance to work occur in a significant proportion of patients. This is a very serious problem as it prevents the main treatment for haemophilia from working.
I play football, run and take part in triathlons – and previously I might have had to infuse both before I took part and possibly after as well. Not having to do that has been absolutely brilliant. – Patient
Professors Edward Tuddenham and Amit Nathwani (UCL Cancer Institute) began a collaboration with St Jude’s Children’s Research Hospital in Tennessee to develop gene therapy for the conditions. They developed new ways to deliver normal copies of these defective proteins to restore the blood-clotting process in haemophilia patients, using a virus as a delivery vehicle. This treatment replaces the need for regular injections with a single-dose treatment, a life-changing approach for haemophilia patients.
The haemophilia B therapy has been successfully used in six severely affected haemophilia B patients, and has proved life-changing. One patient commented that: “I have not needed any of my normal treatment, either preventative or on-demand as a result of an injury. Previously, I used to infuse at home three times a week …. I play football, run and take part in triathlons – and previously I might have had to infuse both before I took part and possibly after as well. Not having to do that has been absolutely brilliant.”
There are also significant economic gains, with estimated savings to the NHS in the first few years of over £1.5m for these six patients alone.
The haemophilia A therapy has been licensed by the US biotech company Biomarin, leading to increased investment in research, and accelerating the move to clinical trials. It is expected that the first patients will be treated towards the end of 2015.