[Current developments in hemostatic treatment for patients with hemophilia]

The supplementation of factor (F-) VIII or F-IX products for hemophilia treatment has helped in preventing arthropathy and considerably improving the quality of life (QOL) of patients. However, serious issues related to hemostatic treatment of hemophilia include the need for repeated intravenous infusion of products, inhibitor development, and hemostatic treatment for patients with inhibitors. To overcome these issues, some extended half-life products and nonclotting factor products were developed. An anti-F-IX/F-X bispecific antibody, emicizumab, which has a longer half life and can be administered subcutaneously, has achieved significant reduction in bleeding in patients with severe hemophilia, irrespective of the inhibitor. Furthermore, clinical trials of si-RNA anti-antithrombin therapy and antitissue factor pathway inhibitor antibody therapy, based on the concept of rebalancing coagulation, have been ongoing. Moreover, gene therapy has been currently developed by the improvement of vector. These newly developed therapies for hemophilia, as a paradigm shift in hemophilia treatment, could provide further improvement in the QOL of patients.