A gene-therapy trial by London researchers has seen remarkable success in finding a long-term cure for Haemophilia A. The trial, by researchers at Barts Health NHS (National Health Service) Trust and Queen Mary University of London, used gene therapy to inject one dose of a missing gene in patients with the condition, and the gene continued functioning in the body for more than a year.

This is the first successful gene therapy to treat the condition. Haemophilia is a hereditary genetic disorder, mostly affecting men, causing people to have low levels of clotting factor VIII, needed for their blood to clot. Lack of the protein factor results in excessive bleeding from even minor injuries and can cause internal bleeding, which is life-threatening.

To date, there is no permanent cure for haemophilia, and patients have to take multiple weekly injections of clotting factor VIII to prevent and control bleeding. "I'm very optimistic that we can deliver long-term treatment benefits," said John Pasi, Haemophilia Centre director at Barts Health NHS Trust and lead author of the study published in the New England Journal of Medicine.