Discovery of a novel class of highly potent, selective, ATP-competitive, and orally bioavailable inhibitors of the mammalian target of rapamycin (mTOR)

J Med Chem. 2013 Mar 28;56(6):2218-34. doi: 10.1021/jm3007933. Epub 2013 Mar 7.

Abstract

A series of novel, highly potent, selective, and ATP-competitive mammalian target of rapamycin (mTOR) inhibitors based on a benzoxazepine scaffold have been identified. Lead optimization resulted in the discovery of inhibitors with low nanomolar activity and greater than 1000-fold selectivity over the closely related PI3K kinases. Compound 28 (XL388) inhibited cellular phosphorylation of mTOR complex 1 (p-p70S6K, pS6, and p-4E-BP1) and mTOR complex 2 (pAKT (S473)) substrates. Furthermore, this compound displayed good pharmacokinetics and oral exposure in multiple species with moderate bioavailability. Oral administration of compound 28 to athymic nude mice implanted with human tumor xenografts afforded significant and dose-dependent antitumor activity.

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Administration, Oral
  • Animals
  • Benzoxazines / chemistry
  • Benzoxazines / metabolism
  • Benzoxazines / pharmacokinetics
  • Benzoxazines / pharmacology
  • Binding, Competitive*
  • Biological Availability
  • Cell Line, Tumor
  • Dogs
  • Drug Discovery*
  • Female
  • Humans
  • Male
  • Mice
  • Models, Molecular
  • Protein Conformation
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / metabolism*
  • Protein Kinase Inhibitors / pharmacokinetics
  • Protein Kinase Inhibitors / pharmacology*
  • Rats
  • Substrate Specificity
  • TOR Serine-Threonine Kinases / antagonists & inhibitors*
  • TOR Serine-Threonine Kinases / chemistry
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Benzoxazines
  • Protein Kinase Inhibitors
  • Adenosine Triphosphate
  • TOR Serine-Threonine Kinases