Linear plot of baseline-corrected FIX activity level after infusion of 25, 50, or 75 IU/kg of rIX-FP (PK population). Mean FIX activity levels of 25, 50, and 75 IU/kg rIX-FP were measured in international units per decaliter. Vertical bars represent SD. A horizontal dotted line represents the 2-IU/dL and 5-IU/dL FIX activity levels.