Sulfonamides as Selective NaV1.7 Inhibitors: Optimizing Potency, Pharmacokinetics, and Metabolic Properties to Obtain Atropisomeric Quinolinone (AM-0466) that Affords Robust in Vivo Activity

J Med Chem. 2017 Jul 27;60(14):5990-6017. doi: 10.1021/acs.jmedchem.6b01850. Epub 2017 Apr 20.

Abstract

Because of its strong genetic validation, NaV1.7 has attracted significant interest as a target for the treatment of pain. We have previously reported on a number of structurally distinct bicyclic heteroarylsulfonamides as NaV1.7 inhibitors that demonstrate high levels of selectivity over other NaV isoforms. Herein, we report the discovery and optimization of a series of atropisomeric quinolinone sulfonamide inhibitors [ Bicyclic sulfonamide compounds as sodium channel inhibitors and their preparation . WO 2014201206, 2014 ] of NaV1.7, which demonstrate nanomolar inhibition of NaV1.7 and exhibit high levels of selectivity over other sodium channel isoforms. After optimization of metabolic and pharmacokinetic properties, including PXR activation, CYP2C9 inhibition, and CYP3A4 TDI, several compounds were advanced into in vivo target engagement and efficacy models. When tested in mice, compound 39 (AM-0466) demonstrated robust pharmacodynamic activity in a NaV1.7-dependent model of histamine-induced pruritus (itch) and additionally in a capsaicin-induced nociception model of pain without any confounding effect in open-field activity.

MeSH terms

  • Analgesics / chemistry
  • Analgesics / pharmacokinetics
  • Analgesics / pharmacology
  • Animals
  • Capsaicin
  • Cell Line
  • Dogs
  • Histamine
  • Mice, Inbred C57BL
  • Molecular Docking Simulation
  • NAV1.7 Voltage-Gated Sodium Channel / metabolism*
  • Pain / chemically induced
  • Pain / prevention & control
  • Protein Isoforms / antagonists & inhibitors
  • Protein Isoforms / metabolism
  • Pruritus / chemically induced
  • Pruritus / prevention & control
  • Quinolones / administration & dosage
  • Quinolones / chemical synthesis
  • Quinolones / chemistry*
  • Quinolones / pharmacokinetics
  • Quinolones / pharmacology
  • Rats
  • Structure-Activity Relationship
  • Sulfonamides / administration & dosage
  • Sulfonamides / chemical synthesis
  • Sulfonamides / chemistry*
  • Sulfonamides / pharmacokinetics
  • Sulfonamides / pharmacology
  • Voltage-Gated Sodium Channel Blockers / chemistry*
  • Voltage-Gated Sodium Channel Blockers / pharmacokinetics
  • Voltage-Gated Sodium Channel Blockers / pharmacology

Substances

  • AM-0466
  • Analgesics
  • NAV1.7 Voltage-Gated Sodium Channel
  • Protein Isoforms
  • Quinolones
  • Sulfonamides
  • Voltage-Gated Sodium Channel Blockers
  • Histamine
  • Capsaicin