Kinetics of transient FVIII inhibitors in the only patient who developed FVIII inhibitors. The patient participated in study NCT02585960. The transient FVIII inhibitor was detected at the week-8 visit and was confirmed at the subsequent month-3 follow-up visit. The FVIII inhibitor had a titer of 0.6 BU/mL, which corresponds to the lowest limit of positivity. Samples taken at all subsequent time points tested negative (<0.6 BU/mL). At the time when the inhibitor was detected, the patient had experienced 176 EDs to rurioctocog alfa pegol, 174 EDs were spent receiving prophylaxis.