Significance of Day-1 Viral Response of Hepatitis C Virus in Patients with Chronic Hepatitis C Receiving Direct-acting Antiviral Therapy

Abstract

Background and Aim

On-treatment response of serum hepatitis C virus (HCV) is reportedly less useful to predict the outcome of anti-HCV therapy with interferon (IFN)-free regimen with direct-acting antivirals (DAAs) than with IFN-based regimens in clinical trials. We evaluated the significance of very early viral response after the start of therapy, which indicates direct HCV response to the drugs, on therapeutic outcome.

Methods

Reductions in serum HCV RNA levels were measured at 1day after the start of therapy in 544 patients who underwent IFN-free DAA regimens. The association between these reductions and the achievement or failure of sustained virologic response (SVR) was evaluated.

Results

Patient characteristics did not influence 1-day reduction in serum HCV RNA except for liver fibrosis. There was no difference in 1-day HCV reduction between SVR and non-SVR patients treated with a 24-week regimen. In contrast, in patients treated with a 12-week regimen, 1-day reduction was significantly greater in SVR than non-SVR patients (p=0.0013), and was predictive of SVR vs. non-SVR (area under the receiver operating characteristics curve: 0.80).

Conclusions

Whereas the reduction in serum HCV RNA levels at 1 day after the start of therapy was not associated with treatment outcomes in patients who underwent a 24-week regimen of IFN-free therapy, there was an association in patients receiving a 12-week regimen, and this reduction was predictive of SVR, thus potentially serving as a factor to identify patients at risk of treatment failure.