In cell culture tests, VGX-410 has been shown to be effective in inhibiting HCV replication with the 50% and 90% effective antiviral concentrations (EC50 and EC90) of 2 and 10 μM, respectively. Furthermore, VGX-410 was shown to act synergistically with interferon-a (IFN-a), the most widely-used drug treatment option available today. When used in combination with a low dose IFN-a at 1 IU/ml, EC90 of VGX-410 was reduced to 3 µM. Moreover, since VGX-410 inhibits viral replication by blocking the cellular protein complex for HCV IRES, there is reduced potential for viral mutation and resistance to this drug.