New weekly treatment option approved for people with haemophilia B

Marstacimab is the first under the skin (subcutaneous) injection for severe haemophilia B and today’s decision comes just weeks after the treatment received its UK licence.

Given as a once-weekly injection under the skin using a pre-filled syringe or pen, marstacimab is also the first haemophilia B treatment that works by targeting a protein in the blood clotting process to help restore normal blood clotting.

Currently people with haemophilia B have to take factor 9 replacement therapy which is given by infusion and is one of only 2 treatments currently available to prevent bleeding episodes.

Marstacimab will be an option for people with severe haemophilia B who weigh at least 35 kg and have not developed antibodies for factor 9 replacement therapy.

Helen Knight, NICE director of medicines evaluation, said: “The independent evaluation committee heard from patients who said they would value a new treatment option for severe haemophilia B. They explained that factor 9 replacement therapy to prevent bleeding requires an infusion, sometimes as often as every 2 to 3 days.

“Marstacimab’s clinical and cost-effectiveness compared with current treatment, together with its once-weekly dosing by injection under the skin means it has the potential to significantly improve the quality of life of people with severe haemophilia B.

“Today’s decision, coming just weeks after the treatment received its UK licence, demonstrates our commitment to getting the best care to people fast, while ensuring value for the taxpayer.”

Haemophilia is a rare, inherited and incurable condition that affects the blood’s ability to clot. People with the condition do not have enough clotting factor in their blood (in haemophilia B this is called factor 9), or it isn’t working properly. This means they cannot form strong clots and so they bleed for longer than usual. Bleeds can be the result of an injury and, when the condition is severe, bleeding into joints and muscles can happen without any injury.

Around 255 people live with severe haemophilia B in England, of who an estimated 205 will be eligible for treatment with marstacimab.

We also looked at marstacimab for treating severe haemophilia A. For people with severe haemophilia A, factor 8, emicizumab and efanesoctocog alfa are options for preventing bleeding episodes. However, the evidence for marstacimab showed that it is not a cost-effective option in this group.