A novel fixed-dose combination treatment for chronic hepatitis C, based on NS5A inhibitor fopitasvir and NS5B inhibitor sofosbuvir.

Drug resistance caused by the extreme genetic variability of zhe hepatitis C virus has rendered effective combinations of drugs indispensable in the treatment of chronic hepatitis C (CHC). Herein, we developed a fixed-dose combination (FDC) treatment containing the NS5B inhibitor sofosbuvir (SOF) and the NS5A inhibitor fopitasvir (FOP). Then the dissolution behavior of FOP in FOP/SOF FDC was improved by co-micronizing FOP with lactose. The enhanced dissolution rate of FOP in the FDC was in good agreement with the behavior of the FOP singledrug tablet. In addition, pharmacokinetic studies showed that both FOP and SOF in the FDC exhibited similar characteristics (area under the curve, Cmax, Tmax, and T1/2) as those of tablets containing FOP or SOF alone. These results revealed that the FOP/SOF FDC represents a potential therapeutic option for the treatment of CHC.