Discovery and Characterization of Clinical Candidate LXE408 as a Kinetoplastid-Selective Proteasome Inhibitor for the Treatment of Leishmaniases

J Med Chem. 2020 Oct 8;63(19):10773-10781. doi: 10.1021/acs.jmedchem.0c00499. Epub 2020 Jul 29.

Abstract

Visceral leishmaniasis is responsible for up to 30,000 deaths every year. Current treatments have shortcomings that include toxicity and variable efficacy across endemic regions. Previously, we reported the discovery of GNF6702, a selective inhibitor of the kinetoplastid proteasome, which cleared parasites in murine models of leishmaniasis, Chagas disease, and human African trypanosomiasis. Here, we describe the discovery and characterization of LXE408, a structurally related kinetoplastid-selective proteasome inhibitor currently in Phase 1 human clinical trials. Furthermore, we present high-resolution cryo-EM structures of the Leishmania tarentolae proteasome in complex with LXE408, which provides a compelling explanation for the noncompetitive mode of binding of this novel class of inhibitors of the kinetoplastid proteasome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiprotozoal Agents / chemistry*
  • Antiprotozoal Agents / pharmacology*
  • Antiprotozoal Agents / therapeutic use
  • Dogs
  • Humans
  • Leishmania donovani / drug effects
  • Leishmania donovani / isolation & purification
  • Leishmania major / drug effects
  • Leishmania major / isolation & purification
  • Leishmaniasis, Visceral / drug therapy*
  • Leishmaniasis, Visceral / parasitology
  • Liver / parasitology
  • Macaca fascicularis
  • Mice
  • Mice, Inbred BALB C
  • Oxazoles / chemistry*
  • Oxazoles / pharmacology*
  • Oxazoles / therapeutic use
  • Proteasome Inhibitors / chemistry*
  • Proteasome Inhibitors / pharmacology*
  • Proteasome Inhibitors / therapeutic use
  • Pyrimidines / chemistry*
  • Pyrimidines / pharmacology*
  • Pyrimidines / therapeutic use
  • Rats
  • Rats, Sprague-Dawley
  • Triazoles / chemistry

Substances

  • Antiprotozoal Agents
  • GNF6702
  • LXE408
  • Oxazoles
  • Proteasome Inhibitors
  • Pyrimidines
  • Triazoles