Sofosbuvir, a nucleotide polymerase inhibitor, for the treatment of chronic hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection is ubiquitous, affecting approximately 180 million individuals worldwide and around 3.2 million in the United States. While peginterferon and ribavirin alone continue to be used, the treatment landscape for patients with genotype 1 has recently changed to include one of two protease inhibitors: boceprevir and telaprevir. Despite this, effective therapies for chronic HCV for all genotypes represent a largely unmet need.Sofosbuvir , formally labeled GS-7977, is an HCV NS5B nucleotide polymerase inhibitor that has entered multiple Phase III trials. Phase II trials demonstrated that treatments including sofosbuvir have higher sustained virologic response rates for genotypes 1, 2, 3, 4 and 6 in comparison with treatments that include only peginterferon and ribavirin. In addition, the side-effect profile of sofosbuvir and ribavirin dual treatment has an improved tolerability in comparison with treatment regimes that include interferon-based options.The hope and expectation is that interferon is eliminated from the armamentarium of HCV therapy and that all-oral therapies prove effective although interferon in combination with multiple drugs may still be required to treat select patients. In addition, there is a need to develop effective therapies for all HCV genotypes with simple and well-tolerated regimes.