Targeting KRAS Mutant Cancers via Combination Treatment: Discovery of a 5-Fluoro-4-(3 H)-quinazolinone Aryl Urea pan-RAF Kinase Inhibitor

J Med Chem. 2021 Apr 8;64(7):3940-3955. doi: 10.1021/acs.jmedchem.0c02085. Epub 2021 Mar 29.

Abstract

Optimization of a series of aryl urea RAF inhibitors led to the identification of type II pan-RAF inhibitor GNE-0749 (7), which features a fluoroquinazolinone hinge-binding motif. By minimizing reliance on common polar hinge contacts, this hinge binder allows for a greater contribution of RAF-specific residue interactions, resulting in exquisite kinase selectivity. Strategic substitution of fluorine at the C5 position efficiently masked the adjacent polar NH functionality and increased solubility by impeding a solid-state conformation associated with stronger crystal packing of the molecule. The resulting improvements in permeability and solubility enabled oral dosing of 7. In vivo evaluation of 7 in combination with the MEK inhibitor cobimetinib demonstrated synergistic pathway inhibition and significant tumor growth inhibition in a KRAS mutant xenograft mouse model.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Azetidines / therapeutic use
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Crystallography, X-Ray
  • Dogs
  • Drug Combinations
  • Drug Synergism
  • Female
  • Humans
  • Madin Darby Canine Kidney Cells
  • Mice
  • Mice, Nude
  • Molecular Structure
  • Mutation
  • Neoplasms / drug therapy*
  • Phenylurea Compounds / chemistry
  • Phenylurea Compounds / metabolism
  • Phenylurea Compounds / therapeutic use*
  • Piperidines / therapeutic use
  • Protein Binding
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / metabolism
  • Protein Kinase Inhibitors / therapeutic use*
  • Quinazolinones / chemistry
  • Quinazolinones / metabolism
  • Quinazolinones / therapeutic use*
  • Structure-Activity Relationship
  • Xenograft Model Antitumor Assays
  • raf Kinases / antagonists & inhibitors*
  • raf Kinases / genetics
  • raf Kinases / metabolism

Substances

  • Azetidines
  • Drug Combinations
  • Phenylurea Compounds
  • Piperidines
  • Protein Kinase Inhibitors
  • Quinazolinones
  • raf Kinases
  • cobimetinib