In the case of hemophilia B, patients are missing the protein factor IX that causes blood to clot. Spontaneous internal bleeding suffered by hemophiliacs can lead to disability and premature death. Current treatment for the disease involves repeated infusions of the missing clotting factor. This treatment is costly, time-consuming and imperfect since the administered clotting factor only remains in the body for a limited time. Damaging bleeds often occur between infusions and result in joint damage, chronic pain and disability.
Present therapies treat only the symptoms of hemophilia rather than the cause.
The goal of gene therapy is to provide the body with the missing genetic information, which will enable it to produce the missing clotting factor. Such a therapy may diminish or eliminate the life-endangering complications common to those suffering with hemophilia. Avigen hopes that Coagulin-B will ultimately provide enough clotting factor to prevent spontaneous bleeding. One of the reasons Avigen s approach to gene therapy holds promise is due to its use of a harmless human virus, AAV, to deliver the necessary genetic information to the patient. Other approaches using different viruses for the transmission of genetic material, such as retroviruses and adenoviruses, have not yet been successful, in part, because the human body treats these viruses as harmful and may trigger an immune response to destroy them, effectively defeating the purpose of the treatment.