Discovery of highly potent and selective Bruton's tyrosine kinase inhibitors: Pyridazinone analogs with improved metabolic stability

Bioorg Med Chem Lett. 2016 Jan 15;26(2):575-579. doi: 10.1016/j.bmcl.2015.11.076. Epub 2015 Nov 24.

Abstract

BTK inhibitor GDC-0834 (1) was found to be rapidly metabolized in human studies, resulting in a suspension of clinical trials. The primary route of metabolism was through cleavage of the acyclic amide bond connecting the terminal tetrahydrobenzothiophene with the central linker aryl ring. SAR studies were focused on reducing metabolic cleavage of this amide, and resulted in the identification of several central aryl linker substituents that conferred improved stability. The most promising substituted aryl linkers were then incorporated into an optimized pyridazinone scaffold, resulting in the identification of lead analog 23, possessing improved potency, metabolic stability and preclinical properties.

Keywords: Bruton’s tyrosine kinase (BTK); Kinase inhibitor; Pyridazinone; Rheumatoid arthritis.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Agammaglobulinaemia Tyrosine Kinase
  • Animals
  • Dogs
  • Humans
  • Mice
  • Microsomes, Liver / metabolism
  • Models, Molecular
  • Protein Kinase Inhibitors / chemistry*
  • Protein Kinase Inhibitors / metabolism
  • Protein Kinase Inhibitors / pharmacokinetics
  • Protein Kinase Inhibitors / pharmacology*
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Protein-Tyrosine Kinases / metabolism
  • Pyridazines / chemistry*
  • Pyridazines / metabolism
  • Pyridazines / pharmacokinetics
  • Pyridazines / pharmacology*
  • Pyrimidinones / chemistry*
  • Pyrimidinones / metabolism
  • Pyrimidinones / pharmacokinetics
  • Pyrimidinones / pharmacology*
  • Rats
  • Thiophenes / chemistry*
  • Thiophenes / metabolism
  • Thiophenes / pharmacokinetics
  • Thiophenes / pharmacology*

Substances

  • N-(3-(6-(4-(1,4-dimethyl-3-oxopiperazin-2-yl)phenylamino)-4-methyl-5-oxo-4,5-dihydropyrazin-2-yl)-2-methylphenyl)-4,5,6,7-tetrahydrobenzo(b)thiophene-2-carboxamide
  • Protein Kinase Inhibitors
  • Pyridazines
  • Pyrimidinones
  • Thiophenes
  • Protein-Tyrosine Kinases
  • Agammaglobulinaemia Tyrosine Kinase
  • BTK protein, human
  • Btk protein, mouse