Discovery of 4-{4-[(3R)-3-Methylmorpholin-4-yl]-6-[1-(methylsulfonyl)cyclopropyl]pyrimidin-2-yl}-1H-indole (AZ20): a potent and selective inhibitor of ATR protein kinase with monotherapy in vivo antitumor activity

J Med Chem. 2013 Mar 14;56(5):2125-38. doi: 10.1021/jm301859s. Epub 2013 Mar 1.

Abstract

ATR is an attractive new anticancer drug target whose inhibitors have potential as chemo- or radiation sensitizers or as monotherapy in tumors addicted to particular DNA-repair pathways. We describe the discovery and synthesis of a series of sulfonylmorpholinopyrimidines that show potent and selective ATR inhibition. Optimization from a high quality screening hit within tight SAR space led to compound 6 (AZ20) which inhibits ATR immunoprecipitated from HeLa nuclear extracts with an IC50 of 5 nM and ATR mediated phosphorylation of Chk1 in HT29 colorectal adenocarcinoma tumor cells with an IC50 of 50 nM. Compound 6 potently inhibits the growth of LoVo colorectal adenocarcinoma tumor cells in vitro and has high free exposure in mouse following moderate oral doses. At well tolerated doses 6 leads to significant growth inhibition of LoVo xenografts grown in nude mice. Compound 6 is a useful compound to explore ATR pharmacology in vivo.

MeSH terms

  • Animals
  • Antineoplastic Agents / therapeutic use
  • Ataxia Telangiectasia Mutated Proteins
  • Cell Cycle Proteins / antagonists & inhibitors*
  • Crystallography, X-Ray
  • Drug Discovery
  • Female
  • HeLa Cells
  • Humans
  • Mice
  • Models, Molecular
  • Morpholines / chemical synthesis*
  • Morpholines / therapeutic use
  • Protein Kinase Inhibitors / chemical synthesis*
  • Protein Kinase Inhibitors / therapeutic use
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Pyrimidines / chemical synthesis*
  • Pyrimidines / therapeutic use
  • Structure-Activity Relationship
  • Xenograft Model Antitumor Assays

Substances

  • 4-(4-(3-methylmorpholin-4-yl)-6-(1-(methylsulfonyl)cyclopropyl)pyrimidin-2-yl)-1H-indole
  • Antineoplastic Agents
  • Cell Cycle Proteins
  • Morpholines
  • Protein Kinase Inhibitors
  • Pyrimidines
  • ATR protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Protein-Serine-Threonine Kinases