Haemophilia B, also called Factor IX (FIX) deficiency, is a genetic disorder caused by missing or defective Factor IX that can result in dangerously low levels of the essential clotting protein. The World Federation of Haemophilia identified over 28,000 males suffering worldwide from haemophilia B in their Annual Global Survey 2013.
For those with severe disease marked by FIX levels of less than one percent of normal, scrapes and bumps are medical emergencies. Painful episodes of spontaneous bleeding can result in crippling joint damage early in life and an increased risk of potentially fatal bleeding within the brain.
Current treatment involves replacement therapy where concentrates of clotting factor are administered intravenously on an on-demand or prophylactic basis. This preventive therapy is usually initiated in patients at a young age and may need to be continued for life. It is hampered by the frequency of administration of up to 3 times per week as well as the high associated costs.