Discovery and Optimization of Quinolinone Derivatives as Potent, Selective, and Orally Bioavailable Mutant Isocitrate Dehydrogenase 1 (mIDH1) Inhibitors

J Med Chem. 2019 Jul 25;62(14):6575-6596. doi: 10.1021/acs.jmedchem.9b00362. Epub 2019 Jul 8.

Abstract

Mutations at the arginine residue (R132) in isocitrate dehydrogenase 1 (IDH1) are frequently identified in various human cancers. Inhibition of mutant IDH1 (mIDH1) with small molecules has been clinically validated as a promising therapeutic treatment for acute myeloid leukemia and multiple solid tumors. Herein, we report the discovery and optimization of a series of quinolinones to provide potent and orally bioavailable mIDH1 inhibitors with selectivity over wild-type IDH1. The X-ray structure of an early lead 24 in complex with mIDH1-R132H shows that the inhibitor unexpectedly binds to an allosteric site. Efforts to improve the in vitro and in vivo absorption, distribution, metabolism, and excretion (ADME) properties of 24 yielded a preclinical candidate 63. The detailed preclinical ADME and pharmacology studies of 63 support further development of quinolinone-based mIDH1 inhibitors as therapeutic agents in human trials.

MeSH terms

  • Allosteric Site / drug effects
  • Animals
  • Biological Availability
  • Cell Line, Tumor
  • Crystallography, X-Ray
  • Dogs
  • Drug Discovery
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / pharmacokinetics
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Humans
  • Isocitrate Dehydrogenase / antagonists & inhibitors*
  • Isocitrate Dehydrogenase / chemistry
  • Isocitrate Dehydrogenase / genetics
  • Madin Darby Canine Kidney Cells
  • Mice
  • Mice, Inbred BALB C
  • Models, Molecular
  • Point Mutation
  • Quinolones / chemistry*
  • Quinolones / pharmacokinetics
  • Quinolones / pharmacology*

Substances

  • Enzyme Inhibitors
  • Quinolones
  • Isocitrate Dehydrogenase
  • IDH1 protein, human