Discovery of Novel 4,5,6,7-Tetrahydro-7 H-pyrazolo[3,4- c]pyridin-7-one Derivatives as Orally Efficacious ATX Allosteric Inhibitors for the Treatment of Pulmonary Fibrosis

J Med Chem. 2025 Jan 9;68(1):792-818. doi: 10.1021/acs.jmedchem.4c02719. Epub 2024 Dec 25.

Abstract

Pulmonary fibrosis (PF) is a progressive, fatal lung disease lacking effective treatments. Autotaxin (ATX) plays a crucial role in exacerbating inflammation and fibrosis, making it a promising target for fibrosis therapies. Herein, starting from PAT-409 (Cudetaxestat), a series of novel ATX inhibitors bearing 1H-indole-3-carboxamide, 4,5,6,7-tetrahydro-7H-pyrazolo[3,4-c]pyridin-7-one, or 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine cores were designed based on the structure of ATX hydrophobic tunnel. The optimal 31 and 35 inhibited ATX with IC50 values of 2.8 and 0.7 nM, respectively. In a bleomycin-induced mouse PF model, both compounds significantly reduced fibrosis by regulating the TGF-β/Smad signaling pathway and downregulating collagen deposition. Furthermore, 35 exhibited both negligibly low hERG channel inhibition (IC50 > 30 μM) and remarkable microsomal stability. Notably, 35 was characterized by favorable pharmacokinetic properties (F = 69.5%) and excellent safety in vivo. Overall, 35 turned out to be a well-characterized potent and safe ATX inhibitor warranting further investigation for the treatment of PF.

MeSH terms

  • Administration, Oral
  • Allosteric Regulation
  • Animals
  • Bleomycin
  • Drug Discovery
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Molecular Docking Simulation
  • Phosphodiesterase Inhibitors / chemical synthesis
  • Phosphodiesterase Inhibitors / chemistry
  • Phosphodiesterase Inhibitors / pharmacokinetics
  • Phosphodiesterase Inhibitors / pharmacology
  • Phosphodiesterase Inhibitors / therapeutic use
  • Phosphoric Diester Hydrolases* / metabolism
  • Pulmonary Fibrosis* / drug therapy
  • Pyrazoles / chemical synthesis
  • Pyrazoles / chemistry
  • Pyrazoles / pharmacokinetics
  • Pyrazoles / pharmacology
  • Pyrazoles / therapeutic use
  • Pyridines / chemical synthesis
  • Pyridines / chemistry
  • Pyridines / pharmacokinetics
  • Pyridines / pharmacology
  • Pyridines / therapeutic use
  • Pyridones / chemical synthesis
  • Pyridones / chemistry
  • Pyridones / pharmacokinetics
  • Pyridones / pharmacology
  • Pyridones / therapeutic use
  • Rats
  • Structure-Activity Relationship

Substances

  • alkylglycerophosphoethanolamine phosphodiesterase
  • Phosphoric Diester Hydrolases
  • Pyrazoles
  • Pyridones
  • Pyridines
  • Bleomycin
  • Phosphodiesterase Inhibitors