Assessment of cytochrome P450-mediated drug-drug interaction potential of orteronel and exposure changes in patients with renal impairment using physiologically based pharmacokinetic modeling and simulation

Biopharm Drug Dispos. 2014 Dec;35(9):543-52. doi: 10.1002/bdd.1919. Epub 2014 Oct 22.


Orteronel is a nonsteroidal, selective inhibitor of 17,20-lyase that was recently in phase 3 clinical development as a treatment for castration-resistant prostate cancer. In humans, the primary clearance route for orteronel is renal excretion. Human liver microsomal studies indicated that orteronel weakly inhibits CYP1A2, 2C8, 2C9 and 2C19, with IC50 values of 17.8, 27.7, 30.8 and 38.8 µm, respectively, whereas orteronel does not inhibit CYP2B6, 2D6 or 3A4/5 (IC50 > 100 µm). Orteronel also does not exhibit time-dependent inhibition of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 or 3A4/5. The results of a static model indicated an [I]/Ki ratio >0.1 for CYP1A2, 2C8, 2C9 and 2C19. Therefore, a physiologically based pharmacokinetic (PBPK) model was developed to assess the potential for drug-drug interactions (DDIs) between orteronel and theophylline, repaglinide, (S)-warfarin and omeprazole, which are sensitive substrates of CYP1A2, 2C8, 2C9 and 2C19, respectively. Simulation of the area under the plasma concentration-time curve (AUC) of these four CYP substrates in the presence and absence of orteronel revealed geometric mean AUC ratios <1.25. Therefore, in accordance with the 2012 US FDA Draft Guidance on DDIs, orteronel can be labeled a 'non-inhibitor' and further clinical DDI evaluation is not required. In PBPK models of moderate and severe renal impairment, the AUC of orteronel was predicted to increase by 52% and 83%, respectively. These results are in agreement with those of a clinical trial in which AUC increases of 38% and 87% were observed in patients with moderate and severe renal impairment, respectively.

Keywords: PBPK; cytochrome P450; drug-drug interaction; orteronel; renal impairment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption, Physiological
  • Aged
  • Antineoplastic Agents / blood
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacokinetics*
  • Computer Simulation*
  • Cytochrome P-450 Enzyme System / metabolism*
  • Drug Interactions
  • Humans
  • Imidazoles / blood
  • Imidazoles / chemistry
  • Imidazoles / pharmacokinetics*
  • Metabolic Clearance Rate
  • Microsomes, Liver / drug effects
  • Microsomes, Liver / enzymology
  • Microsomes, Liver / metabolism
  • Middle Aged
  • Models, Biological*
  • Molecular Structure
  • Molecular Weight
  • Naphthalenes / blood
  • Naphthalenes / chemistry
  • Naphthalenes / pharmacokinetics*
  • Pharmaceutical Preparations / administration & dosage
  • Pharmaceutical Preparations / metabolism
  • Predictive Value of Tests
  • Renal Insufficiency / enzymology
  • Renal Insufficiency / metabolism*
  • Substrate Specificity


  • Antineoplastic Agents
  • Imidazoles
  • Naphthalenes
  • Pharmaceutical Preparations
  • Cytochrome P-450 Enzyme System
  • orteronel