Review article: the efficacy and safety of sofosbuvir, a novel, oral nucleotide NS5B polymerase inhibitor, in the treatment of chronic hepatitis C virus infection

BackgroundThe treatment of chronic hepatitis C is changing rapidly. AimTo review clinical studies of the efficacy and safety of sofosbuvir-containing regimens in the treatment of chronic hepatitis C. MethodsUsing PubMed and search terms sofosbuvir,' emerging HCV treatment,' and HCV polymerase inhibitor,' literature on the clinical development of sofosbuvir, as well as abstracts presented at the November 2013 annual meeting of the American Association for the Study of Liver Diseases (AASLD), was reviewed. The last search was undertaken on 15 November 2014. ResultsIn a dose of 400 mg once daily, the drug has been safe and generally well tolerated with most adverse reactions attributable to the concurrent use of ribavirin or peginterferon plus ribavirin. A high barrier to resistance has been demonstrated. In genotype 1 (G1) patients, the addition of sofosbuvir to peginterferon plus ribavirin yielded sustained virological response rates at week 12 after discontinuation of treatment (SVR12) of about 90% with slightly lower levels in G1b and in patients with cirrhosis, but with no major impact of IL28B genotype, high viral load, body mass index (BMI), alanine aminotransferase (ALT) or race/ethnicity. In genotype 2 (G2), sofosbuvir and ribavirin for 12 weeks also resulted in SVR12 of 90% or better with little effect from cirrhosis. In contrast, genotype 3 (G3) was less responsive to 12 weeks of sofosbuvir plus ribavirin, especially in the presence of cirrhosis. ConclusionThe efficacy and safety of sofosbuvir-containing regimens with ribavirin alone or with peginterferon plus ribavirin signal a new era in treatment.