A practical, one-clinic visit protocol for pharmacokinetic profile generation with the ADVATE(R) myPKFiT(R) dosing tool in severe hemophilia A subjects
Abstract
Standard pharmacokinetic (PK) assessments are demanding for persons with hemophilia A, requiring a 72hr washout and 5-11 timed blood samples. A no-washout, single-clinic visit, sparse sampling population PK (PPK) protocol is an attractive alternative.
Here, we compared PK parameters obtained with a traditional washout, 6-sampling time point PPK protocol with a no-washout, single-clinic visit, reverse 2-sampling time point PPK protocol in persons with severe hemophilia A (SHA) receiving ADVATE(R). 39 inhibitor-negative males with SHA (FVIII:C<2%) were enrolled in a prospective sequential design PK study. Participants completed a washout, 6-sampling time point PPK protocol as well as a no-washout, reverse 2-sampling time point protocol, with samples taken during a single 3hr clinic visit 24hr-post home infusion of FVIII and then 3hr-post infusion in clinic.
FVIII:C levels were analyzed by one-stage and chromogenic assays; blood group and VWF:Ag were determined; and PK parameters were analyzed using the ADVATE(R) myPKFiT(R) dosing tool. There was moderate to almost perfect agreement for the PK parameters obtained with the 2- and the 6-point PPK protocols using a one-stage FVIII:C assay and a substantial to almost perfect agreement using a chromogenic FVIII:C assay.
Significant associations between specific PK parameters and blood group and VWF:Ag were observed. The no-washout, single-clinic visit, reverse 2-sampling time point PPK protocol can be used in the routine clinical setting since it demonstrates sufficient accuracy compared to the more demanding and less practical washout, 6-sampling time point PPK protocol in persons with SHA receiving ADVATE(R).