Identification of Selective Acyl Sulfonamide-Cycloalkylether Inhibitors of the Voltage-Gated Sodium Channel (NaV) 1.7 with Potent Analgesic Activity

J Med Chem. 2019 Jan 24;62(2):908-927. doi: 10.1021/acs.jmedchem.8b01621. Epub 2018 Dec 21.

Abstract

Herein, we report the discovery and optimization of a series of orally bioavailable acyl sulfonamide NaV1.7 inhibitors that are selective for NaV1.7 over NaV1.5 and highly efficacious in in vivo models of pain and hNaV1.7 target engagement. An analysis of the physicochemical properties of literature NaV1.7 inhibitors suggested that acyl sulfonamides with high fsp3 could overcome some of the pharmacokinetic (PK) and efficacy challenges seen with existing series. Parallel library syntheses lead to the identification of analogue 7, which exhibited moderate potency against NaV1.7 and an acceptable PK profile in rodents, but relatively poor stability in human liver microsomes. Further, design strategy then focused on the optimization of potency against hNaV1.7 and improvement of human metabolic stability, utilizing induced fit docking in our previously disclosed X-ray cocrystal of the NaV1.7 voltage sensing domain. These investigations culminated in the discovery of tool compound 33, one of the most potent and efficacious NaV1.7 inhibitors reported to date.

MeSH terms

  • Analgesics / chemistry*
  • Analgesics / metabolism
  • Analgesics / therapeutic use
  • Animals
  • Binding Sites
  • Drug Design
  • Half-Life
  • Humans
  • Male
  • Mice
  • Mice, Transgenic
  • Microsomes, Liver / metabolism
  • Molecular Docking Simulation
  • NAV1.7 Voltage-Gated Sodium Channel / chemistry*
  • NAV1.7 Voltage-Gated Sodium Channel / metabolism
  • Pain / chemically induced
  • Pain / drug therapy
  • Pain / pathology
  • Protein Structure, Tertiary
  • Rats
  • Rats, Sprague-Dawley
  • Structure-Activity Relationship
  • Sulfonamides / chemistry*
  • Sulfonamides / metabolism
  • Sulfonamides / therapeutic use
  • Voltage-Gated Sodium Channel Blockers / chemistry*
  • Voltage-Gated Sodium Channel Blockers / metabolism
  • Voltage-Gated Sodium Channel Blockers / therapeutic use

Substances

  • Analgesics
  • NAV1.7 Voltage-Gated Sodium Channel
  • Sulfonamides
  • Voltage-Gated Sodium Channel Blockers