Gene therapy: reality or myth for the global bleeding disorders community?
In recent years, five different human gene therapy clinical studies have been initiated in the United States, covering a broad spectrum of gene transfer technologies. Both in vivo and ex vivo studies have been performed, and a variety of target organs/tissues have been studied. The results of this early human clinical research indicate that there is still much to be done before a safe and effective gene therapy procedure becomes commercially available, but there is strong evidence that the obstacles that remain will not prove insurmountable. Small increases in circulating clotting factor levels have been achieved in some patients without significant side-effects, providing proof of the principle that gene therapy can provide a therapeutic benefit for patients with haemophilia. Still unclear is whether gene therapy, when it becomes available, will be accessible to the global haemophilia community. As seen with recombinant and other high purity factor concentrates, technological advances do not always lead to improvements in care for the majority of the world's haemophilia patients. In fact, advances in technology can potentially increase the gulf in care if newer processes displace existing manufacturing technologies. A modified vaccine production model should be considered to make gene therapy more widely available to those who presently have inadequate access to treatment.