Clinical example of the fit using the developed integrated VWF-FVIII population PK model. This 33-year-old patient of 69 kg is treated with VWF/FVIII concentrate (ratio 2.4:1) during ankle surgery. The VWF:Act levels (blue lines) and FVIII levels (red lines) are estimated using the new integrated VWF-FVIII population PK model. The observed VWF:Act levels are shown by the blue dots and the observed FVIII levels are shown by the red dots. The dotted lines represent the VWF and FVIII target levels according to clinical guidelines; the shaded are the PK-profiling period and the arrow the start of surgery. The numbers in the graph display the given dose of the VWF/FVIII concentrate according to FVIII dose. (A) The real-life situation in which the patient was treated according to the clinical guidelines, with an initial dose of ∼50 IU/kg followed by ∼25 IU/kg every 12 hours. (B) The hypothetical situation in which the doses needed to achieve the target levels are calculated based on the individual PK parameters of the patient derived from the levels measured during an individual PK profile before surgery.