The Discovery of LML134, a Histamine H3 Receptor Inverse Agonist for the Clinical Treatment of Excessive Sleep Disorders

ChemMedChem. 2019 Jul 3;14(13):1238-1247. doi: 10.1002/cmdc.201900176. Epub 2019 May 21.

Abstract

Histamine H3 receptor (H3R) inverse agonists that have been in clinical trials for the treatment of excessive sleep disorders, have been plagued with insomnia as a mechanism-based side effect. We focused on the identification of compounds that achieve high receptor occupancy within a short time, followed by rapid disengagement from the receptor, a target profile that could provide therapeutic benefits without the undesired side effect of insomnia. This article describes the optimization work that led to the discovery of 1-(1-methyl-6-oxo-1,6-dihydropyridazin-3-yl)piperidin-4-yl 4-cyclobutylpiperazine-1-carboxylate (18 b, LML134).

Keywords: H3 receptor; carbamate; histamine; medicinal chemistry; neurotransmitters.

MeSH terms

  • Animals
  • Drug Evaluation, Preclinical
  • Drug Inverse Agonism
  • Half-Life
  • Histamine Agonists / chemistry
  • Histamine Agonists / pharmacokinetics
  • Histamine Agonists / therapeutic use*
  • Humans
  • Male
  • Microsomes, Liver / metabolism
  • Piperazine / chemistry*
  • Piperazine / pharmacokinetics
  • Piperazine / therapeutic use
  • Piperazines / chemistry*
  • Piperazines / pharmacokinetics
  • Piperazines / therapeutic use
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Histamine H3 / chemistry
  • Receptors, Histamine H3 / metabolism*
  • Sleep Wake Disorders / drug therapy*
  • Structure-Activity Relationship

Substances

  • Histamine Agonists
  • Piperazines
  • Receptors, Histamine H3
  • Piperazine