[Rebalancing therapy for congenital hemophilia]

Conventional treatments for hemophilia have focused on replacing the missing coagulation factor, but a new treatment concept called rebalancing therapy has recently emerged. Rebalancing therapy corrects bleeding tendency by adjusting the balance between coagulation and anticoagulation, and specifically targets TFPI, AT and APC. The anti-TFPI agents concizumab and marstacimab are administered subcutaneously and have been approved for use in Japan. They are monoclonal antibodies that target the K2 domain of TFPI, and improve hemostatic function by inhibiting the binding of TFPI to FXa and TF/FVIIa complexes. The siRNA drug fitusiran is used as an anti-AT agent that reduces the synthesis of AT, and SerpinPC as an anti-APC agent that specifically inhibits APC. This article will outline the concept of rebalancing therapy and the results of clinical trials, as well as precautions and potential issues during treatment.