Apatinib, an oral inhibitor of vascular endothelial growth factor receptor 2（VEGFR-2）, inhibits multiple cytochrome P450 (CYP450) enzymes in vitro. This study in patients with advanced cancer evaluated the effect of Apatinib on CYP450 function by comparing the pharmacokinetics of CYP-specific probe drugs in the presence and absence of Apatinib. The probes used included Nifedipine (CYP3A specific), warfarin (CYP2C9 specific).