The Importance of Being Me: Magic Methyls, Methyltransferase Inhibitors, and the Discovery of Tazemetostat

J Med Chem. 2016 Feb 25;59(4):1556-64. doi: 10.1021/acs.jmedchem.5b01501. Epub 2016 Jan 27.


Posttranslational methylation of histones plays a critical role in gene regulation. Misregulation of histone methylation can lead to oncogenic transformation. Enhancer of Zeste homologue 2 (EZH2) methylates histone 3 at lysine 27 (H3K27) and abnormal methylation of this site is found in many cancers. Tazemetostat, an EHZ2 inhibitor in clinical development, has shown activity in both preclinical models of cancer as well as in patients with lymphoma or INI1-deficient solid tumors. Herein we report the structure-activity relationships from identification of an initial hit in a high-throughput screen through selection of tazemetostat for clinical development. The importance of several methyl groups to the potency of the inhibitors is highlighted as well as the importance of balancing pharmacokinetic properties with potency.

MeSH terms

  • Animals
  • Drug Discovery
  • Enhancer of Zeste Homolog 2 Protein
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / pharmacokinetics
  • Enzyme Inhibitors / pharmacology*
  • Histones / metabolism*
  • Humans
  • Methylation / drug effects*
  • Mice
  • Polycomb Repressive Complex 2 / antagonists & inhibitors*
  • Polycomb Repressive Complex 2 / metabolism
  • Protein Processing, Post-Translational / drug effects
  • Small Molecule Libraries / chemistry*
  • Small Molecule Libraries / pharmacokinetics
  • Small Molecule Libraries / pharmacology*
  • Structure-Activity Relationship


  • Enzyme Inhibitors
  • Histones
  • Small Molecule Libraries
  • EZH2 protein, human
  • Enhancer of Zeste Homolog 2 Protein
  • Polycomb Repressive Complex 2