Daijiworld Media Network – London

London, Jun 13: In a major breakthrough, UK-based researchers have found that a one-time gene therapy approach for haemophilia B remains safe and effective even after 13 years, offering renewed hope for long-term treatment of the rare bleeding disorder.

The findings, published in The New England Journal of Medicine, show a nearly 10-fold reduction in annualised bleeding rates among patients who underwent the therapy, confirming its enduring benefits.

Haemophilia B, an X-linked genetic disorder affecting roughly 1 in 25,000 male births, results from low levels of a clot-promoting protein called factor IX. The disease causes spontaneous and often life-threatening bleeding episodes.

Scientists from St Jude Children’s Research Hospital and University College London conducted the gene therapy trial between 2010 and 2012. Ten adult males with severe haemophilia B received a one-time intravenous infusion.

"The key benefit is that gene therapy is a one-time, simple intravenous infusion that potentially has positive effects for a lifetime," said Dr Andrew Davidoff of St Jude.

After more than a decade of follow-up, all patients have maintained steady levels of factor IX and remain largely free from bleeding episodes. Notably, no long-term side effects or toxic events have been reported.

"This long-term data is incredibly promising. Factor levels have remained stable over 13 years, and we've not seen recurring liver inflammation or other adverse effects," said Dr Ulrike Reiss, the study's principal investigator.

While mild liver inflammation was observed shortly after treatment, it was effectively managed with steroids and did not recur. Over 90 per cent of the administered vector ends up in the liver.

This groundbreaking therapy may signal a transformative shift in how haemophilia B is treated, offering patients a future free from the burdens of lifelong clotting factor infusions.