Researchers at University College London (UCL) and at St Jude Children’s Research Hospital in Memphis in the US have pioneered a gene therapy that could reduce the need for adults with haemophilia B to get injections in order to prevent bleeds.
Symptoms improved significantly in adults with the bleeding disorder haemophilia B following a single treatment with gene therapy developed by the research teams in London and Memphis.
The researchers have asserted that the findings of the six-person study mark the first proof that gene therapy can reduce disabling, painful bleeding episodes in patients with the inherited blood disorder haemophilia B.
Results of the Phase I study have appeared in the New England Journal of Medicine. The research was also presented on 11 December at the 53rd annual meeting of the American Society of Hematology in San Diego, California.
Four study participants stopped receiving protein injections to prevent bleeding episodes after undergoing the therapy and have not suffered spontaneous bleeding, according to a spokesperson at UCL.
The study participants were all treated at the Royal Free Hospital in London under the care of Prof Edward Tuddenham, a pioneer in the field of blood coagulation and a study co-author.
"This is a potentially life-changing treatment for patients with this disease and an important milestone for the field of gene therapy. It could have ramifications for the treatment of haemophilia A, other protein and liver disorders and chronic diseases such as cystic fibrosis," said first author Dr Amit Nathwani of the UCL Cancer Institute, Royal Free Hospital, University College Hospital and NHS Blood and Transplant (NHSBT).
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 individuals inherit the mutation.
Previous efforts to ease haemophilia B symptoms by introducing a correct copy of the gene have been unsuccessful, said the researchers yesterday at UCL.
The research was funded in part by The Katharine Dormandy Trust, Medical Research Council, Wellcome Trust, NHS Blood and Transplant and the UCLH/UCL National Institute for Health Research Biomedical Research Centre, all in the UK. In the US, the research was funded by the National Institutes of Health, the Assisi Foundation of Memphis and ALSAC.