UNC5293, a potent, orally available and highly MERTK-selective inhibitor

Eur J Med Chem. 2021 Aug 5:220:113534. doi: 10.1016/j.ejmech.2021.113534. Epub 2021 May 17.

Abstract

Inhibition of MER receptor tyrosine kinase (MERTK) causes direct tumor cell killing and stimulation of the innate immune response. Therefore, MERTK has been identified as a therapeutic target in a wide variety of human tumors. Clinical trials targeting MERTK have recently been initiated, however, none of these drugs are MERTK-specific. Herein, we present the discovery of a highly MERTK-selective inhibitor UNC5293 (24). UNC5293 has subnanomolar activity against MERTK with an excellent Ambit selectivity score (S50 (100 nM) = 0.041). It mediated potent and selective inhibition of MERTK in cell-based assays. Furthermore, it has excellent mouse PK properties (7.8 h half-life and 58% oral bioavailability) and was active in bone marrow leukemia cells in a murine model.

Keywords: Alkyl pyrrolopyrimidine; Cancer immunotherapy; MERTK; MERTK-Specific inhibitor; Magic methyl; TAM kinase.

MeSH terms

  • Administration, Oral
  • Animals
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Humans
  • Mice
  • Mice, Congenic
  • Mice, Inbred NOD
  • Molecular Structure
  • Protein Kinase Inhibitors / administration & dosage
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / pharmacology*
  • Structure-Activity Relationship
  • c-Mer Tyrosine Kinase / antagonists & inhibitors*
  • c-Mer Tyrosine Kinase / metabolism

Substances

  • Protein Kinase Inhibitors
  • MERTK protein, human
  • c-Mer Tyrosine Kinase