Pronounced antiepileptic activity of the subtype-selective GABAA -positive allosteric modulator PF-06372865 in the GAERS absence epilepsy model

CNS Neurosci Ther. 2019 Feb;25(2):255-260. doi: 10.1111/cns.13046. Epub 2018 Aug 12.

Abstract

Aim: Antiepileptic drugs that modulate GABA have the potential to aggravate or improve the symptoms of absence epilepsy. PF-06372865 is a positive allosteric modulator (PAM) of α2/3/5 subunit-containing GABAA receptors with minimal activity at α1-containing receptors, which are believed to mediate many of the adverse events associated with benzodiazepines. The aim of this study was to assess the antiepileptic effect of PF-06372865 in a preclinical model of absence seizures.

Methods: Genetic absence epilepsy rats from Strasbourg (GAERS) was implanted with four cortical electrodes over the frontoparietal cortex, and the number and cumulated duration of spike-and-wave discharges (SWDs) were recorded for 10-90 minutes following administration of vehicle, PF-06372865, and positive controls diazepam and valproate.

Results: PF-06372865 (0.3, 1, 2, 10 mg kg-1 ) dose-dependently reduced the expression of SWDs, including full suppression at the highest doses by 30 minutes after administration.

Conclusions: PF-06372865 demonstrated robust efficacy in suppressing SWDs in the GAERS model of absence epilepsy. To our knowledge, this is the first demonstration of antiepileptic activity of an α2/3/5-subtype-selective GABAA PAM in a model of absence epilepsy. Further study of the antiepileptic properties of PF-06372865 is warranted in patients with absence seizures.

Keywords: GABA; GAERS; PF-06372865 (total ≥5; absence; epilepsy; ≤8).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anticonvulsants / therapeutic use*
  • Diazepam / therapeutic use
  • Dose-Response Relationship, Drug
  • Electrocorticography
  • Electrodes, Implanted
  • Electroencephalography
  • GABA Modulators / therapeutic use*
  • Imidazoles / therapeutic use*
  • Male
  • Pyridazines / therapeutic use*
  • Rats
  • Receptors, GABA-A / drug effects*
  • Seizures / drug therapy*
  • Valproic Acid / therapeutic use

Substances

  • Anticonvulsants
  • GABA Modulators
  • Imidazoles
  • PF-06372865
  • Pyridazines
  • Receptors, GABA-A
  • Valproic Acid
  • Diazepam