title: PhRMA CPCDC initiative on predictive models of human pharmacokinetics, part 2: comparative assessment of prediction methods of human volume of distribution.
abstract: The objective of this study was to evaluate the performance of various empirical, semimechanistic and mechanistic methodologies with and without protein binding corrections for the prediction of human volume of distribution at steady state (Vss ). PhRMA member companies contributed a set of blinded data from preclinical and clinical studies, and 18 drugs with intravenous clinical pharmacokinetics (PK) data were available for the analysis. In vivo and in vitro preclinical data were used to predict Vss by 24 different methods. Various statistical and outlier techniques were employed to assess the predictability of each method. There was not simply one method that predicts Vss accurately for all compounds. Across methods, the maximum success rate in predicting human Vss was 100%, 94%, and 78% of the compounds with predictions falling within tenfold, threefold, and twofold error, respectively, of the observed Vss . Generally, the methods that made use of in vivo preclinical data were more predictive than those methods that relied solely on in vitro data. However, for many compounds, in vivo data from only two species (generally rat and dog) were available and/or the required in vitro data were missing, which meant some methods could not be properly evaluated. It is recommended to initially use the in vitro tissue composition-based equations to predict Vss in preclinical species and humans, putting the assumptions and compound properties into context. As in vivo data become available, these predictions should be reassessed and rationalized to indicate the level of confidence (uncertainty) in the human Vss prediction. The top three methods that perform strongly at integrating in vivo data in this way were the Øie-Tozer, the rat -dog-human proportionality equation, and the lumped-PBPK approach. Overall, the scientific benefit of this study was to obtain greater characterization of predictions of human Vss from several methods available in the literature.
authors: Modeling and Simulation, DMPK, AstraZeneca Ltd., Macclesfield, Cheshire SK10 3JL, UK.
authors: Rhys Do
authors: RD
authors: Jones
authors: Hannah M
authors: HM
authors: Jones
authors: Malcolm
authors: M
authors: Rowland
authors: Christopher R
authors: CR
authors: Gibson
authors: James W T
authors: JW
authors: Yates
authors: Jenny Y
authors: JY
authors: Chien
authors: Barbara J
authors: BJ
authors: Ring
authors: Kimberly K
authors: KK
authors: Adkison
authors: M Sherry
authors: MS
authors: Ku
authors: Handan
authors: H
authors: He
authors: Ragini
authors: R
authors: Vuppugalla
authors: Punit
authors: P
authors: Marathe
authors: Volker
authors: V
authors: Fischer
authors: Sandeep
authors: S
authors: Dutta
authors: Vikash K
authors: VK
authors: Sinha
authors: Thorir
authors: T
authors: Björnsson
authors: Thierry
authors: T
authors: Lavé
authors: Patrick
authors: P
authors: Poulin
mesh_terms: D022126:Access to Information; D061605:Administration, Intravenous; D000818:Animals; D003198:Computer Simulation; D003299:Cooperative Behavior; D062313:Databases, Pharmaceutical; D004285:Dogs; D055808:Drug Discovery / Q000379:methods*; D004353:Drug Evaluation, Preclinical; D006801:Humans; D033183:Interdisciplinary Communication; D008954:Models, Biological; D015233:Models, Statistical; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D010599:Pharmacokinetics; D016730:Program Development; D015397:Program Evaluation; D011485:Protein Binding; D051381:Rats; D015203:Reproducibility of Results; D013045:Species Specificity
chemical_list: D004364:Pharmaceutical Preparations