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Gene therapy success could lead to cure for haemophilia


A new gene therapy that has been trialled at the NIHR Imperial Clinical Research Facility could be the first step towards a cure for haemophilia.

People with haemophilia A, the most common type of haemophilia, have a genetic defect that means they do not produce a clotting factor called exogenous factor VIII. Current treatment involves weekly injections of a drug to replace this clotting protein.

In this trial the new therapy, which was developed at University College London, was tested in nine people with severe haemophilia A. Participants received a single dose of the new therapy, which replaces the faulty genes to increase levels of factor VIII.

Six of the seven people who received a high dose experienced an increase in factor VIII to normal levels and fewer bleeding events, an effect that was still present a year after the therapy dose. Factor VIII increased to the level of mild haemophilia in the seventh patient.

Professor John Pasi, Haemophilia Centre Director at Barts Health NHS Trust, another study site, said: "We have seen mind-blowing results which have far exceeded our expectations. When we started out we thought it would be a huge achievement to show a five per cent improvement, so to actually be seeing normal or near normal factor levels with dramatic reduction in bleeding is quite simply amazing. We really now have the potential to transform care for people with haemophilia."

Dosing for the trial, published in New England Journal of Medicine, took place at the NIHR Imperial Clinical Research Facility. The trial was sponsored by BioMarin Pharmaceutical.

The team will now hold further tests with participants around the world, including people in the USA, Europe, Africa and South America.

Read coverage of the trial on the BBC website.