Responding to the challenge of untreatable gonorrhea: ETX0914, a first-in-class agent with a distinct mechanism-of-action against bacterial Type II topoisomerases

Sci Rep. 2015 Jul 14:5:11827. doi: 10.1038/srep11827.

Abstract

With the diminishing effectiveness of current antibacterial therapies, it is critically important to discover agents that operate by a mechanism that circumvents existing resistance. ETX0914, the first of a new class of antibacterial agent targeted for the treatment of gonorrhea, operates by a novel mode-of-inhibition against bacterial type II topoisomerases. Incorporating an oxazolidinone on the scaffold mitigated toxicological issues often seen with topoisomerase inhibitors. Organisms resistant to other topoisomerase inhibitors were not cross-resistant with ETX0914 nor were spontaneous resistant mutants to ETX0914 cross-resistant with other topoisomerase inhibitor classes, including the widely used fluoroquinolone class. Preclinical evaluation of ETX0914 pharmacokinetics and pharmacodynamics showed distribution into vascular tissues and efficacy in a murine Staphylococcus aureus infection model that served as a surrogate for predicting efficacious exposures for the treatment of Neisseria gonorrhoeae infections. A wide safety margin to the efficacious exposure in toxicological evaluations supported progression to Phase 1. Dosing ETX0914 in human volunteers showed sufficient exposure and minimal adverse effects to expect a highly efficacious anti-gonorrhea therapy.

Publication types

  • Clinical Trial, Phase I

MeSH terms

  • Adult
  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use*
  • Barbiturates / chemistry
  • Barbiturates / pharmacology*
  • Barbiturates / therapeutic use*
  • DNA Topoisomerases, Type II / chemistry
  • Disease Models, Animal
  • Dogs
  • Dose-Response Relationship, Drug
  • Drug Resistance, Bacterial
  • Female
  • Fluoroquinolones / pharmacology
  • Gonorrhea / drug therapy*
  • Gonorrhea / microbiology
  • Haplorhini
  • Humans
  • Isoxazoles
  • Male
  • Mice
  • Microbial Sensitivity Tests
  • Middle Aged
  • Models, Molecular
  • Molecular Conformation
  • Morpholines
  • Mutation
  • Neisseria gonorrhoeae / drug effects
  • Neisseria gonorrhoeae / genetics
  • Oxazolidinones
  • Rats
  • Spiro Compounds / chemistry
  • Spiro Compounds / pharmacology*
  • Spiro Compounds / therapeutic use*
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / drug effects
  • Topoisomerase II Inhibitors / chemistry
  • Topoisomerase II Inhibitors / pharmacology*
  • Topoisomerase II Inhibitors / therapeutic use*
  • Young Adult

Substances

  • Anti-Bacterial Agents
  • Barbiturates
  • Fluoroquinolones
  • Isoxazoles
  • Morpholines
  • Oxazolidinones
  • Spiro Compounds
  • Topoisomerase II Inhibitors
  • DNA Topoisomerases, Type II
  • zoliflodacin