Patients with the bleeding disorder haemophilia B have been given new hope thanks to a new gene therapy trialled at the Royal Free.
The gene therapy, developed by researchers at St Jude Children's Research Hospital in Memphis, United States, was used in six Royal Free patients under the care of Professor Edward Tuddenham, director of the haemophilia centre at the Royal Free and a pioneer in the field of blood coagulation.
A single treatment was found to significantly improve patients’ symptoms, reducing the need for protein injections to prevent spontaneous bleeds. Several have also participated in marathons and other activities that would have been difficult before they received the gene therapy.
"The results on the first six patients have been both highly informative and very encouraging. We are proceeding with the trial in order to establish the most effective safe dose. We hope to complete the study with a further 20 to 30 patients recruited in the UK, in Europe and in North America,” said Professor Tuddenham.
“If we can show that safety and efficacy in maintained then we expect to apply for a license during 2012. The gene therapy drug could be available for worldwide use as early as 2013”.
The findings of the study have now been published in the New England Journal of Medicine and presented to the annual meeting of the American Society of Haematology on 11 December.
Amit Nathwani, from the UCL department of haematology based at the Royal Free was also one of the report’s authors.
"This is a potentially life-changing treatment for patients with this disease and an important milestone for the field of gene therapy,” he said.
“It could have ramifications for the treatment of haemophilia A, other protein and liver disorders and chronic diseases such as cystic fibrosis.”
People with haemophilia B cannot produce a protein called factor IX, which is critical for blood-clotting.
Normally, patients have factor IX levels less than one per cent. After treatment, levels of factor IX ranged from two per cent to 12%. Even modest increases can dramatically improve a patient’s quality of life and reduce bleeding episodes.
Sebastian Misztal, 31, a company director from North Finchley who participated in the study, said: “Once injected, you become immune so can’t be injected for a second time if it doesn’t work. But I was willing to take that risk.
“Nothing could be worse than what I have now. It might be too late for me, as my joints were already very damaged by the haemophilia, but it could help others.
“It’s been amazing. I’ve had no side effects and I don’t have to inject myself twice a week, which was not pleasant.
en I cut myself shaving, for example, the bleeding just stops – which wasn’t happening before.”
Previous efforts to ease haemophilia B symptoms by introducing a correct copy of the gene have been unsuccessful.
Notes to editors:
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Haemophilia B is caused by an inherited mistake in the gene for making a protein called Factor IX, which is essential for normal blood clotting. The gene is carried on the X chromosome. As a result, haemophilia B is almost exclusively a disease of men. About one in 30,000 people inherit the mutation