Discovery of Potent and Orally Bioavailable Macrocyclic Peptide-Peptoid Hybrid CXCR7 Modulators

J Med Chem. 2017 Dec 14;60(23):9653-9663. doi: 10.1021/acs.jmedchem.7b01028. Epub 2017 Oct 30.

Abstract

The chemokine receptor CXCR7 is an attractive target for a variety of diseases. While several small-molecule modulators of CXCR7 have been reported, peptidic macrocycles may provide advantages in terms of potency, selectivity, and reduced off-target activity. We produced a series of peptidic macrocycles that incorporate an N-linked peptoid functionality where the peptoid group enabled us to explore side-chain diversity well beyond that of natural amino acids. At the same time, theoretical calculations and experimental assays were used to track and reduce the polarity while closely monitoring the physicochemical properties. This strategy led to the discovery of macrocyclic peptide-peptoid hybrids with high CXCR7 binding affinities (Ki < 100 nM) and measurable passive permeability (Papp > 5 × 10-6 cm/s). Moreover, bioactive peptide 25 (Ki = 9 nM) achieved oral bioavailability of 18% in rats, which was commensurate with the observed plasma clearance values upon intravenous administration.

MeSH terms

  • Administration, Oral
  • Animals
  • Biological Availability
  • Dogs
  • Humans
  • Macrocyclic Compounds / administration & dosage
  • Macrocyclic Compounds / chemistry
  • Macrocyclic Compounds / pharmacokinetics
  • Macrocyclic Compounds / pharmacology
  • Madin Darby Canine Kidney Cells
  • Male
  • Molecular Docking Simulation
  • Peptides / administration & dosage
  • Peptides / chemistry*
  • Peptides / pharmacokinetics
  • Peptides / pharmacology*
  • Peptoids / administration & dosage
  • Peptoids / chemistry*
  • Peptoids / pharmacokinetics
  • Peptoids / pharmacology*
  • Rats
  • Rats, Wistar
  • Receptors, CXCR / agonists*
  • Receptors, CXCR / metabolism*

Substances

  • ACKR3 protein, human
  • Macrocyclic Compounds
  • Peptides
  • Peptoids
  • Receptors, CXCR