Regorafenib (BAY 73-4506): a new oral multikinase inhibitor of angiogenic, stromal and oncogenic receptor tyrosine kinases with potent preclinical antitumor activity

Int J Cancer. 2011 Jul 1;129(1):245-55. doi: 10.1002/ijc.25864. Epub 2011 Apr 22.

Abstract

Angiogenesis, a critical driver of tumor development, is controlled by interconnected signaling pathways. Vascular endothelial growth factor receptor (VEGFR) 2 and tyrosine kinase with immunoglobulin and epidermal growth factor homology domain 2 play crucial roles in the biology of normal and tumor vasculature. Regorafenib (BAY 73-4506), a novel oral multikinase inhibitor, potently inhibits these endothelial cell kinases in biochemical and cellular kinase phosphorylation assays. Furthermore, regorafenib inhibits additional angiogenic kinases (VEGFR1/3, platelet-derived growth factor receptor-β and fibroblast growth factor receptor 1) and the mutant oncogenic kinases KIT, RET and B-RAF. The antiangiogenic effect of regorafenib was demonstrated in vivo by dynamic contrast-enhanced magnetic resonance imaging. Regorafenib administered once orally at 10 mg/kg significantly decreased the extravasation of Gadomer in the vasculature of rat GS9L glioblastoma tumor xenografts. In a daily (qd)×4 dosing study, the pharmacodynamic effects persisted for 48 hr after the last dosing and correlated with tumor growth inhibition (TGI). A significant reduction in tumor microvessel area was observed in a human colorectal xenograft after qd×5 dosing at 10 and 30 mg/kg. Regorafenib exhibited potent dose-dependent TGI in various preclinical human xenograft models in mice, with tumor shrinkages observed in breast MDA-MB-231 and renal 786-O carcinoma models. Pharmacodynamic analyses of the breast model revealed strong reduction in staining of proliferation marker Ki-67 and phosphorylated extracellular regulated kinases 1/2. These data demonstrate that regorafenib is a well-tolerated, orally active multikinase inhibitor with a distinct target profile that may have therapeutic benefit in human malignancies.

MeSH terms

  • Angiogenesis Inhibitors / pharmacology*
  • Animals
  • Antineoplastic Agents / pharmacology*
  • Cell Proliferation / drug effects
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Magnetic Resonance Imaging
  • Mice
  • Mice, Nude
  • Phenylurea Compounds / pharmacology*
  • Phosphorylation
  • Protein Kinase Inhibitors / pharmacology*
  • Pyridines / pharmacology*
  • Rats
  • Rats, Inbred F344

Substances

  • Angiogenesis Inhibitors
  • Antineoplastic Agents
  • Enzyme Inhibitors
  • Phenylurea Compounds
  • Protein Kinase Inhibitors
  • Pyridines
  • regorafenib