F8 and hemophilia A: Therefore, gene therapy does offer the first potential and promising cure for hemophilia A. Moreover, as gene therapy consists of a single treatment event and even small increases in circulating fVIII plasma levels (>10 pM) can provide significant clinical benefits for patients with hemophilia A, gene therapy may be a more cost-effective option than factor replacement therapy for a large, worldwide population of patients with hemophilia A with limited access to treatment.