Sofosbuvir for the treatment of chronic hepatitis C : between current evidence and future perspectives

In recent years, clinical research in the field of new treatments for chronic hepatitis C (HCV) has been devoted to developing regimens based on direct-acting antivirals (DAAs), with the goal of increasing treatment efficacy and improving tolerability and safety. This can be achieved by Peginterferon (PegIFN)-free anti-HCV regimens, as PegIFN is responsible for many side effects and limits treatment access due to contraindications in some patient categories. Sofosbuvir (SOF) is the first compound to enter the market with IFN-free combination regimens; it belongs to the nucleotide inhibitors of viral polymerase NS5B and acts as a chain terminator during the HCV replication process, exhibiting pan-genotypic antiviral activity with a high barrier to resistance. Clinical trials in HCV genotype 2/3 patients have demonstrated optimal efficacy in HCV-2, where the combination SOF/ribavirin (Rbv) for 12 weeks resulted in >90% sustained virological response (SVR) rates, while HCV-3 patients with advanced liver fibrosis and previous failure to PegIFN plus Rbv therapy still require individualized and optimized treatment strategies. Historically difficult-to-treat genotypes HCV-1, -4-6 can benefit from reduced duration of PegIFN plus SOF and Rbv, while IFN-free regimens in these patients will be based on SOF in combination with other DAA classes. Due to an optimal tolerability and safety profile with no significant drug-to-drug interactions, SOF is currently undergoing clinical trials in the setting of pre- and post-liver transplantation and HIV-coinfected patients, with the objective to address the until now unmet need for safe and efficient treatment in these populations. This article provides an overview of SOF features and the main clinical trials, discussing key results and potential future developments.