Real-life Clinical FEIBA Samples Measured Using the Version A of the HemA EnzySystem

The goal of this observational study is to assess if the version A of the HemA EnzySystem, a novel portable coagulation testing platform, can be used in patients with hemophilia A treated with Factor VIII Bypassing Agent (FEIBA). The main question\[s\] it aims to answer are: * Can the version A of the HemA EnzySystem can record thrombin generation within a time frame of 60 min in fresh whole blood samples of patients with hemophilia A treated with FEIBA? * Are the TGA results of the version A of the HemA EnzySystem in agreement with the TGA results obtained with conventional methods in fresh non frozen plasma? Participants are asked to fill in a questionnaire regarding their general health and hemophilia treatment. Subsequently, blood will be drawn from the patients before, and at 30, 120, and 240 minutes after FEIBA administration. Whole blood is immediately tested using the Version A HemA EnzySystem, and plasma is generated for testing with the Ceveron s100 (Technoclone). Leftover samples are frozen for later additional coagulation testing.