RO8191 (CDM-3008), an imidazonaphthyridine compound, is an orally active and potent interferon (IFN) receptor agonist. RO8191 directly binds to IFNα/β receptor 2 (IFNAR2) and activates IFN-stimulated genes (ISGs) expression and JAK/STAT phosphorylation. RO8191 shows antiviral activity against both HCV and EMCV with an IC50 of 200 nM for HCV replicon[1]. RO8191 is a cccDNA modulator (CDM) through interferon-like activity and has anti-HBV activity[2].