Novel inhibitor of p38 MAP kinase as an anti-TNF-alpha drug: discovery of N-[4-[2-ethyl-4-(3-methylphenyl)-1,3-thiazol-5-yl]-2-pyridyl]benzamide (TAK-715) as a potent and orally active anti-rheumatoid arthritis agent

J Med Chem. 2005 Sep 22;48(19):5966-79. doi: 10.1021/jm050165o.


The p38 mitogen-activated protein (MAP) kinase has been implicated in the proinflammatory cytokine signal pathway, and its inhibitors are potentially useful for the treatment of chronic inflammatory diseases such as rheumatoid arthritis (RA) and inflammatory bowel disease. To develop a new drug for RA, we synthesized a novel series of 4-phenyl-5-pyridyl-1,3-thiazoles and evaluated their inhibition of p38 MAP kinase, lipopolysaccharide (LPS)-stimulated release of tumor necrosis factor-alpha (TNF-alpha) from human monocytic THP-1 cells in vitro, and LPS-induced TNF-alpha production in vivo in mice. During the course of the study, we found that these compounds risk the inhibition of cytochrome P450 (CYP) isoforms by coordination of the 4-pyridyl nitrogen with heme iron. We therefore investigated the effects of substitution at the 2-position of the pyridyl ring on the inhibitory activity of p38 MAP kinase and CYPs in more detail. As a result, N-[4-[2-ethyl-4-(3-methylphenyl)-1,3-thiazol-5-yl]-2-pyridyl]benzamide (8h, TAK-715) exhibited potent inhibitory activity in these assays (inhibition of p38alpha, IC50 = 7.1 nM; LPS-stimulated release of TNF-alpha from THP-1, IC50 = 48 nM; LPS-induced TNF-alpha production in mice, 87.6% inhibition at 10 mg/kg, po) and no inhibitory activity for major CYPs, including CYP3A4. This compound also showed good bioavailability in mice and rats and significant efficacy in a rat adjuvant-induced arthritis model. Compound 8h was selected as a clinical candidate and is now under clinical investigation for the treatment of RA.

MeSH terms

  • Administration, Oral
  • Animals
  • Antirheumatic Agents / chemical synthesis*
  • Antirheumatic Agents / chemistry
  • Antirheumatic Agents / pharmacology
  • Arthritis, Experimental / drug therapy*
  • Arthritis, Rheumatoid / drug therapy*
  • Benzamides / chemical synthesis*
  • Benzamides / chemistry
  • Benzamides / pharmacology
  • Biological Availability
  • Cell Line
  • Cell Line, Tumor
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme Inhibitors
  • Humans
  • In Vitro Techniques
  • Isoenzymes / antagonists & inhibitors
  • Male
  • Mice
  • Microsomes / drug effects
  • Microsomes / enzymology
  • Models, Molecular
  • Monocytes / drug effects
  • Monocytes / metabolism
  • Rats
  • Rats, Inbred Lew
  • Structure-Activity Relationship
  • Thiazoles / chemical synthesis*
  • Thiazoles / chemistry
  • Thiazoles / pharmacology
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors*
  • Tumor Necrosis Factor-alpha / metabolism
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors*


  • Antirheumatic Agents
  • Benzamides
  • Cytochrome P-450 Enzyme Inhibitors
  • Isoenzymes
  • N-(4-(2-ethyl-4-(3-methylphenyl)-1,3-thiazol-5-yl)-2-pyridyl)benzamide
  • Thiazoles
  • Tumor Necrosis Factor-alpha
  • CYP3A protein, human
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human
  • p38 Mitogen-Activated Protein Kinases