Summary
Disorders caused by inborn genetic errors have been a primary target for treatment
by gene transfer. Hemophilia A and B have been considered especially important targets
because the genes for factor VIII and IX are well characterized, levels of factor
VIII and IX do not require complex regulation, small increases in factor level would
have significant clinical benefits, good clinical and laboratory tests of efficacy
exist, and excellent animal models of hemophilia are available. Four clinical trials
of gene transfer in hemophilia, two in hemophilia A and two in hemophilia B, are currently
underway or have been completed and two other trials have been approved. The collective
interim results from these trials indicate that the current approaches and doses are
safe and that low levels of expression are detected. These studies support the continued
development of gene transfer as a potential treatment option for hemophilia.
Key words
Hemophilia - gene therapy - retrovirus - adeno-associated virus - adenovirus