Real-life effectiveness and safety of sofosbuvir-based therapy in genotype 2 chronic hepatitis C patients in South Korea, with emphasis on the ribavirin dose

Background/Aims: Sofosbuvir (SOF)-based therapy has been used in Korean patients with chronic hepatitis C virus (HCV) infection since January 2016. This study aimed to investigate the real-life effectiveness and safety of SOF-based therapy in genotype 2 HCV infection. Methods: From January to December 2016, 458 genotype 2 HCV-infected patients who received ≥1 dose of SOF-based therapy were consecutively enrolled in seven tertiary hospitals. Sustained virologic response (SVR) rates and safety were determined by intention-to-treat (ITT) and per-protocol (PP) analyses. Results: The mean age of the patients was 61.0 years; 183 (40%) were male, and 13.1% showed a high viral load (>6,000,000 IU/ mL). Among the 378 treatment-naïve patients, the SVR rates were 94.2% (ITT) and 96.7% (PP). Among the 80 treatment-experienced patients, the SVR rates were 96.3% (ITT) and 98.7% (PP). Patients with a relatively high fibrosis-4 index score (>3.25) had similar SVR rates to those with a relatively low score (p=0.756). A total of 314 patients (68.6%) were treated with a reduced ribavirin dose at the prescriber's discretion, but they showed similar SVR rates to those treated with the weight-based dose (ITT: 95.5% and 92.3%, PP: 97.4% and 96.3%, respectively). Adverse events were observed in 191 patients (41.7%), including 86 (18.8%) with anemia, but only one (0.2%) discontinued antiviral therapy due to nausea. Conclusions: SOF-based therapy showed high real-life efficacy and tolerability in Korean patients with genotype 2 chronic HCV infection, regardless of previous antiviral treatment experience and fibrosis score. A reduced ribavirin dose can be considered in this patient cohort.