A new gene therapy can substantially cut the risk of bleeding in people with the rare condition haemophilia B, according to a new study.
Researchers found people who received a single injection of the gene therapy, called FLT180a, did not need to inject themselves every week with clotting factors – proteins that help control bleeding.
Haemophilia is a rare condition that impacts the blood’s ability to clot.
It is typically inherited and mainly affects men.
People with the condition lack clotting factors, which mix with blood cells called platelets to stop bleeding after cuts and injuries.
They can still suffer debilitating joint damage – a consequence of the condition – even with the weekly injections currently available.
Haemophilia A is caused by a lack of factor VIII and is more common, while haemophilia B is caused by a deficiency of factor IX.
In a new 26-week trial led by the Royal Free Hospital, University College London and biotechnology company Freeline Therapeutics, experts found that a single treatment with FLT180a led to sustained production of the protein from the liver in nine out of 10 patients with severe or moderately severe haemophilia.
Lead author Professor Pratima Chowdary, from UCL, said: “Removing the need for haemophilia patients to regularly inject themselves with the missing protein is an important step in improving their quality of life.
“The long-term follow-up study will monitor the patients for durability of expression and surveillance for late effects.”
Patients on the trial had to take immune suppressing drugs over several weeks to several months to keep their immune systems from rejecting the treatment.
While the therapy was generally well received, all patients experienced side effects.
One who received the highest FLT180a dose developed an abnormal blood clot.
Professor Amit Nathwani, who co-founded Freeline, a company focused on liver-directed gene therapies, said: “Gene therapy is still a young field that pushes the boundaries of science for people with severe genetic diseases.”
He said the trial, which was published in the New England Journal of Medicine, adds to “the growing body of evidence that gene therapy has the potential to free patients from the challenges of having to adhere to lifelong therapy or could provide treatment where none exists today”.