Figure 1.
Comparing use of average PK parameters to individualized PK profiles. The figure represents the % time spent over 0.01 IU/mL for 10 hypothetical patients. In blue, the time spent by each patient was calculated when they were treated with a standard half-life factor VIII; below each patient label, the U/kg administered to obtain the displayed results. On average, the population of patients was treated with 30 UI/kg and spent 68% of their time above 0.01 IU/mL, with a minimum of 45 and a maximum of 90. The orange columns show the % time spent over 0.01 IU/mL obtained by switching all patients to the same dosage of an extended half-life concentrate; the average time spent over 0.01 IU/mL increases to 100, ranging from 68% to >100%. The green columns show the % time spent over 0.01 IU/mL obtained by switching all patients to the extended half-life concentrate adjusting their dose to their PK (the 5 patients identified by the green arrows had their dose decreases, those identified by the red arrows had their dose increased); the average time spent over 0.01 IU/mL increases to 100, ranging from 95% to >100%. Note that we have hypothesized not to decrease the dose of patient number 3 because it is treated with 20 IU/kg. The average dose in the population would remain 30 IU/kg.