Where top-down meets bottom-up: Combined population PK (PopPk) and PBPK approaches to evaluate the impact of food and gastric pH on the pharmacokinetics of GDC-0941

Authors: Lu T, Fraczkiewicz G, Salphati L, Budha N, Dalziel G, Smelick GS, Davis JD, Dresser M, Ware JA, Jin JY
Conference: ASCPT
Keywords: food, gastric absorption, gastric emptying, gastric pH, pharmacokinetics, pKa, PopPK
Software: GastroPlus®
Division: PBPK

Background

  • The phosphoinositide 3-kinase (P13K) signaling pathway is deregulated in a wide variety of cancers. GDC-0941 is a potent and selective pan-inhibitor of class I P13K. It demonstrates excellent in vivo activity in tumor xenograft models and is currently in clinical drug development.
  • GDC-0941 is in multiple clinical trials for various cancers (e.g. BC, mBC, NSCLC).
  • Based on its physiochemical properties – high permeability and poor solubility at physiologically relevant pH values 9 4- 7.5), GDC-0941 classfies as BCS class II drug, GDC-0941 belongs to the group of compounds known for their highly variable absorption that is dictated by their solubility vs. pH profile characteristics.
  • Because of the steep pH-dependent solubility profile in vitro, a Phase I, randomized, open-label study was conducted in healthy volunteers to investigate the effect of food and porton pump inhibitor (PPI) on GDC-0941.

By Grace Fraczkiewicz

ASCPT 115th Annual Meeting in Atlanta, Georgia, March 18-22, 2014,