Safety of relaxing coagulation control by anti-TFPI in hemophilia patients: impact of tissue distribution of tissue factor.

Prophylactic treatment by substitution of the missing coagulation factors has been the cornerstone of hemophilia treatment for the last 50 years. However, prophylactic treatment can be burdensome and sometimes inefficient, particularly in patients with inhibitors. Novel approaches in management of hemophilia are focused on products that would ease the prophylactic treatment, i.e. have a long half-life and subcutaneous applicability, and efficacy irrespective of the presence of inhibitors. Novel non-replacement therapies target different points in the coagulation cascade with the aim to enhance thrombin generation, either by inhibition of natural inhibitors, like antithrombin (AT) and tissue factor pathway inhibitor (TFPI), or by acting as a bi-specific antibody which mimics factor (F) VIII and has capability of bridging FIXa and FX (1).