A world‐wide survey and field study in clinical haemostasis laboratories to evaluate <scp>FVIII</scp>:C activity assay variability of <scp>ADYNOVATE</scp> and <scp>OBIZUR</scp> in comparison with <scp>ADVATE</scp>

One-stage clotting assays can and will be used with sufficient accuracy and precision for the measurement of ADYNOVATE, OBIZUR and ADVATE in plasma samples from subjects with haemophilia A. Chromogenic assay underestimates OBIZUR potency, particularly at lower concentrations.