Sofosbuvir plus daclatasvir with or without ribavirin for chronic hepatitis C infection: Impact of drug concentration on viral load decay

BACKGROUND:Sofosbuvir (SOF) plus daclatasvir (DCV) with or without ribavirin is one of the currently recommended treatment option for chronic hepatitis C. AIMS:Our objectives were to identify factors associated with SOF/DCV plasma concentrations [C] variations and to evaluate their impact on viral kinetics. METHODS:130 consecutive HCV patients initiating SOF/DCV therapy with or without ribavirin were enrolled. Clinical, biological, virological and pharmacological data were collected at baseline, at week 4, 8, 12, and 24 of therapy and 12 weeks after the end of therapy. RESULTS:Mean age was 57 years, 68% of patients were males, 69% were infected by HCV genotype 1 and cirrhosis was observed in 76% of patients. Multivariate analysis showed that higher SOF [C] and DCV [C] during treatment were associated with eGFR impairment and absence of cirrhosis. We found a significant correlation between the magnitude of HCV viral load decrease from day 0 to week 4 and a higher SOF [C] at week 4 (p=0.032) and a higher DCV [C] at week 8 (p=0.013). CONCLUSIONS:Pharmacological monitoring showed significant associations between elevated SOF or DCV [C] and absence of cirrhosis, decreased eGFR and viral load decrease during the first month of treatment.