New drugs for hepatitis C virus.

No new therapy has been approved for the treatment of chronic hepatitis C in the last 5 years in the USA since the approval of pegylated interferon (IFN)-alpha(2a) and ribavirin. Multiple new drugs are currently in development and are expected to be approved for use in the USA and/or the EU by 2011-2013. Although the mechanism of action of pegylated IFN and ribavirin are not completely known, it is likely that they will continue to be used in combination regimens for a number of years. Direct antivirals are likely to be the first new drugs to be used in combination with pegylated IFN and ribavirin. Viral resistance will prove to be a significant barrier and require that consolidation therapy with at least 24 weeks of pegylated IFN and ribavirin be used to successfully prevent the selection or emergence of resistant variants. Numerous other compounds, such as ribavirin analogs, long-acting IFNs, hepatoprotectants and immunomodulators, are in development and may replace the drugs that are used currently. The combination of direct antivirals, such as protease and polymerase inhibitors, may rapidly follow in development, as has occurred in HIV drug therapy.