Identification and Optimization of Novel Small c-Abl Kinase Activators Using Fragment and HTS Methodologies

J Med Chem. 2019 Feb 28;62(4):2154-2171. doi: 10.1021/acs.jmedchem.8b01872. Epub 2019 Feb 11.

Abstract

Abelson kinase (c-Abl) is a ubiquitously expressed, nonreceptor tyrosine kinase which plays a key role in cell differentiation and survival. It was hypothesized that transient activation of c-Abl kinase via displacement of the N-terminal autoinhibitory "myristoyl latch", may lead to an increased hematopoietic stem cell differentiation. This would increase the numbers of circulating neutrophils and so be an effective treatment for chemotherapy-induced neutropenia. This paper describes the discovery and optimization of a thiazole series of novel small molecule c-Abl activators, initially identified by a high throughput screening. Subsequently, a scaffold-hop, which exploited the improved physicochemical properties of a dihydropyrazole analogue, identified through fragment screening, delivered potent, soluble, cell-active c-Abl activators, which demonstrated the intracellular activation of c-Abl in vivo.

MeSH terms

  • Animals
  • Binding Sites
  • Drug Discovery
  • High-Throughput Screening Assays
  • Humans
  • Mice
  • Molecular Structure
  • Protein Binding
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / metabolism
  • Protein Kinase Inhibitors / pharmacology*
  • Proto-Oncogene Proteins c-abl / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-abl / chemistry
  • Proto-Oncogene Proteins c-abl / metabolism
  • Pyrazoles / chemistry
  • Pyrazoles / metabolism
  • Pyrazoles / pharmacology*
  • Structure-Activity Relationship
  • Thiazoles / chemistry
  • Thiazoles / metabolism
  • Thiazoles / pharmacology*

Substances

  • Protein Kinase Inhibitors
  • Pyrazoles
  • Thiazoles
  • Proto-Oncogene Proteins c-abl