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.
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.
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).
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.