The discovery of I-BET726 (GSK1324726A), a potent tetrahydroquinoline ApoA1 up-regulator and selective BET bromodomain inhibitor

J Med Chem. 2014 Oct 9;57(19):8111-31. doi: 10.1021/jm5010539. Epub 2014 Sep 24.


Through their function as epigenetic readers of the histone code, the BET family of bromodomain-containing proteins regulate expression of multiple genes of therapeutic relevance, including those involved in tumor cell growth and inflammation. BET bromodomain inhibitors have profound antiproliferative and anti-inflammatory effects which translate into efficacy in oncology and inflammation models, and the first compounds have now progressed into clinical trials. The exciting biology of the BETs has led to great interest in the discovery of novel inhibitor classes. Here we describe the identification of a novel tetrahydroquinoline series through up-regulation of apolipoprotein A1 and the optimization into potent compounds active in murine models of septic shock and neuroblastoma. At the molecular level, these effects are produced by inhibition of BET bromodomains. X-ray crystallography reveals the interactions explaining the structure-activity relationships of binding. The resulting lead molecule, I-BET726, represents a new, potent, and selective class of tetrahydroquinoline-based BET inhibitors.

MeSH terms

  • Aminoquinolines / chemical synthesis*
  • Aminoquinolines / pharmacokinetics
  • Aminoquinolines / pharmacology
  • Animals
  • Anti-Inflammatory Agents / chemical synthesis*
  • Anti-Inflammatory Agents / pharmacokinetics
  • Anti-Inflammatory Agents / pharmacology
  • Apolipoprotein A-I / metabolism*
  • Benzoates / chemical synthesis*
  • Benzoates / pharmacokinetics
  • Benzoates / pharmacology
  • Cell Cycle Proteins
  • Drug Discovery
  • Humans
  • Mice
  • Nuclear Proteins / antagonists & inhibitors*
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Quinolines / chemical synthesis*
  • Quinolines / pharmacokinetics
  • Quinolines / pharmacology
  • Structure-Activity Relationship
  • Transcription Factors / antagonists & inhibitors*


  • 4-(1-acetyl-4-((4-chlorophenyl)amino)-2-methyl-1,2,3,4-tetrahydroquinolin-6-yl)benzoic acid
  • Aminoquinolines
  • Anti-Inflammatory Agents
  • Apolipoprotein A-I
  • BRD2 protein, human
  • BRD4 protein, human
  • Benzoates
  • Cell Cycle Proteins
  • Nuclear Proteins
  • Quinolines
  • Transcription Factors
  • 1,2,3,4-tetrahydroquinoline
  • Protein-Serine-Threonine Kinases

Associated data

  • PDB/4UYF
  • PDB/4UYG
  • PDB/4UYH