TABLE 3

Calculated model parameters and predicted AUCR values for the 3D regimen based on a mechanistic static model or basic model for reversible P450/UGT inhibition for individual components or the combined regimen

EnzymeParitaprevirRitonavirOmbitasvirDasabuvirM13D Regimen
Predicted 
AUCRPredicted 
AUCRPredicted 
AUCRPredicted 
AUCRPredicted R1Predicted cAUCRObserved cAUCRPredicted/
Observed
CYP2C91.171.011.170.9a1.3
CYP2C191.021.001.020.6a1.7
CYP3A428.228.257b0.5
UGT1A11.041.051.001.061.031.202.4c0.5
  • Dashes indicate that parameters were not calculated because the IC50 could not be estimated due to no or low inhibition at the highest tested concentration in vitro. Predicted AUCR calculations for the reversible P450 inhibition using the mechanistic static model are described in eq. 1. The predicted R1 calculation is from a modified basic model for predicting reversible P450 inhibition: R1= 1 + [I]/Ki, where [I] is the unbound Cmax of the inhibitor and Ki (or IC50/2) is the in vitro inhibition constant. M1 is a metabolite of dasabuvir; thus, the R1 model was used for DDI predictions. cAUCR is the combination AUCR prediction (as described in Materials and Methods).

  • a Menon et al. (2015).

  • b Badri et al. (2015).

  • c Khatri et al. (2016).