Comparative pharmacokinetics and pharmacodynamics of the advanced Retinol-Binding Protein 4 antagonist in dog and cynomolgus monkey

PLoS One. 2020 Jan 24;15(1):e0228291. doi: 10.1371/journal.pone.0228291. eCollection 2020.

Abstract

Accumulation of lipofuscin bisretinoids in the retina contributes to pathogenesis of macular degeneration. Retinol-Binding Protein 4 (RBP4) antagonists reduce serum retinol concentrations thus partially reducing retinol delivery to the retina which decreases bisretinoid synthesis. BPN-14136 is a novel RBP4 antagonist with good in vitro potency and selectivity and optimal rodent pharmacokinetic (PK) and pharmacodynamic (PD) characteristics. To select a non-rodent species for regulatory toxicology studies, we conducted PK and PD evaluation of BPN-14136 in dogs and non-human primates (NHP). PK properties were determined following oral and intravenous administration of BPN-14136 in beagle dogs and cynomolgus monkeys. Dynamics of plasma RBP4 reduction in response to compound administration was used as a PD marker. BPN-14136 exhibited favorable PK profile in both species. Dose-normalized exposure was significantly higher in NHP than in dog. Baseline concentrations of RBP4 were considerably lower in dog than in NHP, reflecting the atypical reliance of canids on non-RBP4 mechanisms of retinoid trafficking. Oral administration of BPN-14136 to NHP induced a strong 99% serum RBP4 reduction. Dynamics of RBP4 lowering in both species correlated with compound exposure. Despite adequate PK and PD characteristics of BPN-14136 in dog, reliance of canids on non-RBP4 mechanisms of retinoid trafficking precludes evaluation of on-target toxicities for RBP4 antagonists in this species. Strong RBP4 lowering combined with good PK attributes and high BPN-14136 exposure achieved in NHP, along with the biology of retinoid trafficking that is similar to that of humans, support the choice of NHP as a non-rodent safety species.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intravenous
  • Administration, Oral
  • Animals
  • Dogs
  • Macaca fascicularis
  • Male
  • Models, Animal
  • Retinol-Binding Proteins, Plasma / analysis*
  • Retinol-Binding Proteins, Plasma / antagonists & inhibitors
  • Small Molecule Libraries / administration & dosage
  • Small Molecule Libraries / pharmacokinetics*

Substances

  • Retinol-Binding Proteins, Plasma
  • Small Molecule Libraries