Monte Carlo simulation for rFIXFc doses to achieve a trough of 1 IU/dL (1%) or 3 IU/dL (3%) above baseline. The rFIXFc dosing intervals considered were (A) weekly, (B) every 10 days, or (C) every 2 weeks. The mean population PK parameters and relevant intersubject and intrasubject variability were adopted from this phase1/2a study. On the basis of the simulated activity-time profiles, the mean and 95% CI of the activity-time profiles of the 1000 subjects was constructed graphically for different dosing regimens for a total of 5 dosing cycles when the steady state was achieved.