Evaluation of ITX 5061, a scavenger receptor B1 antagonist: resistance selection and activity in combination with other hepatitis C virus antivirals

J Infect Dis. 2012 Feb 15;205(4):656-62. doi: 10.1093/infdis/jir802.

Abstract

ITX 5061 is a scavenger receptor B1 antagonist that has entered phase 1 clinical trials in hepatitis C virus (HCV)-infected humans. We evaluated ITX 5061 in combination with interferon-α, ribavirin, and HCV protease and polymerase inhibitors in a genotype 2a infectious virus system. ITX 5061 is a potent inhibitor of HCV replication and is additive to synergistic with interferon-α, ribavirin, BILN2061, VX950, VX1, and 2'-C-methyladenosine. Resistance selection experiments were performed using a Jc1-FEO virus co-culture system and intermittent ITX 5061 exposure under neomycin selection. We identified a mutant virus with a substitution of aspartic acid for asparagine at the highly conserved position 415 in E2 (N415D). Introduction of this mutation into wild-type virus conferred high-level resistance to ITX 5061. There was no cross-resistance between ITX 5061 and HCV protease inhibitors or interferon-α. These results suggest that ITX 5061 is a promising compound for study in combination with other HCV inhibitors.

Publication types

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

MeSH terms

  • Antiviral Agents / pharmacology*
  • Cell Line
  • Drug Resistance, Viral*
  • Hepacivirus / drug effects*
  • Hepacivirus / genetics*
  • Humans
  • Interferon-alpha / pharmacology
  • Microbial Sensitivity Tests
  • Mutation, Missense
  • Ribavirin / pharmacology
  • Scavenger Receptors, Class B / antagonists & inhibitors*
  • Virus Replication / drug effects

Substances

  • Antiviral Agents
  • Interferon-alpha
  • SCARB1 protein, human
  • Scavenger Receptors, Class B
  • Ribavirin