Objective To evaluate the performance of myPKFiT,a tool guiding the dosing of antihemophilic factor (recombinant) plasma/albumin-free method (rAHF-PFM),in maintaining the coagulation factor Ⅷ (FⅧ) level above a target threshold at the steady state and estimating the pharmacokinetics (PK) parameters in hemophilia A patients in China. Methods The data of 9 patients with severe hemophilia A in a trial (CTR20140434) assessing the safety and efficacy of rAHF-PFM in the Chinese patients with hemophilia A were analyzed.The myPKFiT was used to predict the adequate dose to maintain a patient's FⅧ level above target threshold at the steady state.Furthermore,the performance of myPKFiT in estimating the pharmacokinetics parameters of individuals was evaluated. Results Twelve combinations of two dosing intervals and six sparse sampling schedules were investigated,and 57%-88% of the patients remained the FⅧ level above the target threshold of 1 U/dl (1%) for at least 80% of the dosing interval.The clearance and time to FⅧ level of 1% obtained from sparse sampling by myPKFiT were similar to those obtained from extensive sampling. Conclusions The myPKFiT can provide adequate dose estimates to maintain the FⅧ level above the target threshold at the steady state in Chinese patients with severe hemophilia A.Moreover,it demonstrates good performance for estimating key pharmacokinetics parameters,including clearance and time to FⅧ level of 1%.
Keywords: coagulation factor Ⅷ; hemophilia A; myPKFiT; pharmacokinetics.