Hope for thousands with hemophilia as another injection can drastically reduce the risk of dangerous bleeding

A monthly injection could be life-changing for hemophiliacs after it was found to significantly reduce bleeding.

Trials of the treatment called Fitusiran have shown that it stops bleeding in up to two-thirds (66 per cent) of people with haemophilia A or B.

Experts say preventive treatment can quickly improve patients’ daily lives by reducing hospital visits.

Hemophilia is a commonly inherited condition that affects the blood’s ability to clot and puts patients at risk of severe bleeding.

It affects around 9,000 people, mostly men, in the UK, with patients often treated with clotting factor medicines to replicate what is missing, or inert medicines if they bleed.

But the preventive drugs must be injected regularly, usually every other day for hemophilia A and 2-3 times a week for hemophilia B.

They can also become less effective over time because some people who take blood clotting factor medications develop antibodies in their immune system called inhibitors.

It uses a new type of treatment called small interfering RNA (siRNA) that disrupts the production of certain proteins.

Fitusiran is the first siRNA developed for hemophilia and targets a protein called antithrombin, which reduces blood clotting to increase its ability to clot.

In the first study, 25 of 38 (66 percent) participants with inhibitors who received Fitusiran injections had no bleeding after nine months, compared with 1 of 19 (5 percent) who received an on-demand bypass drug.

A study of patients without inhibitors found that 40 out of 79 (51 percent) of those who received the monthly shots had no bleeding, compared with 2 out of 40 (5 percent) in the other group, according to results published in The Lancet Hematology.

However, possible side effects such as blood clotting and liver damage require further investigation, according to the researchers.

University of Southern California Professor Guy Young, who led the study, said: “The data are encouraging and suggest that this could be the first prophylactic treatment – meaning it could be given to prevent bleeding, in instead of stopping it after they are treated… – which works in both hemophilia A and hemophilia B patients with inhibitors.

“Treatment options for hemophilia B patients are currently limited to on-demand treatments that treat bleeding after it has occurred.”

Professor Alok Srivastava of Christian Medical College, Vellore, India, and co-author of the study, said: “Because this drug is administered once a month or less, the treatment burden is significantly reduced.

“This means patients with haemophilia can manage their condition with fewer hospital visits, which can be worrying and disruptive to daily life. This will lead to a better quality of life.”