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hemophilia article

New Factor IX Treatment for Hemophilia B

By Laura Linnemeier

Most of the time when we cut ourselves, whether it be from a clumsy move with a paring knife or an aggressive paper cut, our body is able to handle the trauma by slowing and stopping the bleeding. This clotting process is orchestrated by several proteins, known as factors, which work together in a process called the coagulation cascade. The coagulation cascade forms a blood clot at the injury site and, ultimately, stops the bleeding. However, some people are born with significantly decreased amounts of these proteins. The name of this disease is hemophilia. Without the appropriate factor levels, the coagulation cascade is not as effective, leading to decreased clotting and increased bleeding time. In other words, these people take a longer time to stop bleeding.

 

Patients with hemophilia have particular trouble with something called hemarthrosis, bleeding within the joint. When a person with a healthy coagulation cascade bumps their knee on a coffee table, they get a hematoma (a bruise), which heals in a couple of days. When a person with hemophilia bumps their knee, they very easily start bleeding into their joint. This process can be extremely painful and uncomfortable. Patients with hemophilia can also run into trouble if they require surgery for a non-related issue. It is difficult for surgeons to control bleeding during an operation when a patient has clotting difficulties. This situation can be life-threatening and great care must be taken to prepare hemophiliac patients with the proper medical therapy.

 

Depending on which specific factor is deficient, hemophilia is further classified as Hemophilia A, B, or C. A recent article from the New England Journal of Medicine talks about a new therapy for Hemophilia B, a disease caused by a lack of a coagulation protein called Factor IX. Current treatment plans for hemophiliacs are simply to replace the deficient factor. This article discusses a newly developed form of Factor IX that can be injected and stay in the body for a longer period of time. While many hemophiliacs have to receive their factor at least twice a week, this new version allows patients to only dose once every 1 to 2 weeks. The article also discusses the benefits of factor dosing in hemophiliacs preventatively, on a regular basis, versus dosing on an as-needed basis after a bleeding event has already occurred. The study found that prophylactic dosing leads to fewer bleeding events overall.

 

What this means for you:

In summary, hemophilia is a disease of increased bleeding time due to dysfunction of the coagulation cascade. It is difficult to stop bleeding in hemophiliacs because they are missing important proteins that aid in blood clotting when they have an injury. Treatment for this disease involves replenishing the deficient protein. A recent article studied the safety and effectiveness of a new way to deliver this protein. This new development allows patients to undergo fewer injections. The article also showed that treating hemophiliacs for bleeding events before they happen decreases the chance of reoccurrence.

 

Citation

Powell JS, Pasi KJ, Ragni MV, et al. Phase 3 study of recombinant factor IX Fc fusion protein in hemophilia B. New England Journal of Medicine. Dec 12 2013;369:2313-2323.