Discovery of the investigational drug TAK-441, a pyrrolo[3,2-c]pyridine derivative, as a highly potent and orally active hedgehog signaling inhibitor: modification of the core skeleton for improved solubility

Bioorg Med Chem. 2012 Sep 15;20(18):5507-17. doi: 10.1016/j.bmc.2012.07.034. Epub 2012 Jul 27.

Abstract

We recently reported the discovery of the novel pyrrolo[3,2-c]quinoline-4-one derivative 1 as a potent inhibitor of Hedgehog (Hh) pathway signaling. However, the PK evaluation of 1 at high dosage (100 mg/kg) revealed the C(max) value 3.63 μg/mL, likely due to poor solubility of this compound. Efforts to improve solubility by reducing the aromatic ring count of the core system led to N-methylpyrrolo[3,2-c]pyridine derivative 11. Further optimization of the 3-alkoxy group led to compound 11d with acceptable solubility and potent Hh inhibitory activity. Compound 11d suppressed transcription factor Gli1 mRNA expression in tumor-associated stromal tissue and inhibited tumor growth (treatment/control ratio, 3%) in a mouse medulloblastoma allograft model owing to the improved PK profile based on increased solubility. Compound 11d (TAK-441) is currently in clinical trials for the treatment of advanced solid tumors.

MeSH terms

  • Animals
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drug Discovery*
  • Hedgehog Proteins / antagonists & inhibitors*
  • Hedgehog Proteins / metabolism
  • Humans
  • Kruppel-Like Transcription Factors / antagonists & inhibitors
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism
  • Medulloblastoma / drug therapy*
  • Mice
  • Mice, Nude
  • Models, Molecular
  • Molecular Structure
  • NIH 3T3 Cells
  • Pyridines / administration & dosage
  • Pyridines / chemical synthesis
  • Pyridines / chemistry
  • Pyridines / pharmacology*
  • Pyrroles / administration & dosage
  • Pyrroles / chemical synthesis
  • Pyrroles / chemistry
  • Pyrroles / pharmacology*
  • RNA, Messenger / antagonists & inhibitors
  • RNA, Messenger / genetics
  • Signal Transduction / drug effects*
  • Solubility
  • Structure-Activity Relationship
  • Transplantation, Homologous
  • Zinc Finger Protein GLI1

Substances

  • Antineoplastic Agents
  • Gli1 protein, mouse
  • Hedgehog Proteins
  • Kruppel-Like Transcription Factors
  • Pyridines
  • Pyrroles
  • RNA, Messenger
  • TAK-441
  • Zinc Finger Protein GLI1
  • pyrrolo(3,2-c)pyridine