Discovery of a Small Molecule Activator of Slack (Kcnt1) Potassium Channels That Significantly Reduces Scratching in Mouse Models of Histamine-Independent and Chronic Itch

Adv Sci (Weinh). 2024 Apr;11(15):e2307237. doi: 10.1002/advs.202307237. Epub 2024 Feb 13.

Abstract

Various disorders are accompanied by histamine-independent itching, which is often resistant to the currently available therapies. Here, it is reported that the pharmacological activation of Slack (Kcnt1, KNa1.1), a potassium channel highly expressed in itch-sensitive sensory neurons, has therapeutic potential for the treatment of itching. Based on the Slack-activating antipsychotic drug, loxapine, a series of new derivatives with improved pharmacodynamic and pharmacokinetic profiles is designed that enables to validate Slack as a pharmacological target in vivo. One of these new Slack activators, compound 6, exhibits negligible dopamine D2 and D3 receptor binding, unlike loxapine. Notably, compound 6 displays potent on-target antipruritic activity in multiple mouse models of acute histamine-independent and chronic itch without motor side effects. These properties make compound 6 a lead molecule for the development of new antipruritic therapies targeting Slack.

Keywords: drug development; itch; kcnt1; slack; target validation.

MeSH terms

  • Animals
  • Antipruritics / therapeutic use
  • Histamine / metabolism
  • Loxapine / therapeutic use
  • Mice
  • Potassium Channels* / metabolism
  • Pruritus* / drug therapy
  • Pruritus* / metabolism

Substances

  • Antipruritics
  • Histamine
  • Loxapine
  • Potassium Channels