Researchers from The Children’s Hospital of Philadelphia, PA, have identified a mutant human protein that has shown promise for treating the bleeding disorder hemophilia. Share on Pinterest Around 20,000 people in the US are living with hemophilia, and around 400 babies are born with the condition every year. Published in the journal Blood, the study reveals how the protein – named FIX-Padua – successfully relieved symptoms of hemophilia in three dogs with severe forms of the disease. It is estimated that around 20,000 people in the US are living with hemophilia, and around 400 babies are born with the condition every year. The disorder primarily affects males. Hemophilia is a primarily inherited condition caused by a mutation in a gene responsible for producing proteins in the blood needed for normal blood clotting, called clotting factors. As a result, people with hemophilia are prone to internal bleeding – particularly in the joints – and prolonged bleeding following an injury. The two main types of hemophilia are A and B. Hemophilia A is where a person is missing or has low levels of the clotting factor VIII, whereas hemophilia B is where an individual is missing or has low levels of clotting factor IX. The lower the levels of a certain clotting factor, the more severe the disorder is.

The search for new hemophilia treatments The most common form of treatment for hemophilia is replacement therapy, whereby a patient undergoes intravenous infusion of clotting factors in order to help replace the ones that are low or missing. However, this treatment has significant downfalls; patients with more severe hemophilia may need frequent sessions, which is expensive and time consuming. In addition, some patients can develop antibodies that attack and destroy the clotting factors before they have a chance to work. For many years, researchers have been investigating the use of gene therapy as an alternative treatment option for patients with hemophilia. One gene therapy strategy that has shown some promise involves injecting patients with vectors – nondisease carrying viruses – to carry DNA sequences that hold a genetic code that enables clotting factor production. However, early trials of this technique have raised concern. Vectors appear to trigger a strong immune response, and the higher the vector dose, the stronger the immune response is. As such, the researchers of this latest study – led by Dr. Valder R. Arruda, a hematology researcher at The Children’s Hospital of Philadelphia (CHOP) – set out to find a technique that delivers lower vector doses to reduce immune response, while effectively producing clotting factors.