Short article: Viral dynamics among hepatitis C virus chronic infected patients during direct-acting antiviral agents therapy: impact for monitoring and optimizing treatment duration.

Objectives: Direct-acting antiviral agents (DAAs) have provided an ultimate treatment duration of 12 weeks for most hepatitis C virus (HCV)-infected patients. The opportunity to reduce treatment duration to 6 or 8 weeks is being evaluated. Here, the HCV viral dynamics at short times during HCV therapies and its implications for monitoring and optimizing treatment duration have been assessed.

Patients And Methods: HCV chronic infected patients who began HCV therapy (March 2014 to June 2015) at a reference hospital of the Northwest of Spain were selected. HCV-RNA was quantified at different short time points during HCV therapy using Abbott RealTime HCV assay. Epidemiological, clinical, and virological data were recorded.

Results: Eleven HCV-infected patients were included; 90.9% had cirrhosis (>12.5 kPa) and 72.7% were treatment-experienced. HCV genotype 1b was the most prevalent (72.7%). All of the combinations were pegylated interferon-free and all included ribavirin. The median HCV-RNA (log IU/ml) at baseline was 5.8 (5.4-6.1); the decline between baseline and day 3, weeks 4, 8, and 12 was 3.2, 4.8, 5.1, and 5.6, respectively. Fewer than 50% of patients achieved undetectable viral load at weeks 4 and 8; however, all patients achieved a sustained virologic response at 12 weeks.

Conclusion: Rapid and high HCV-RNA decline was observed among HCV-infected patients under DAA-based regimens, especially for those without cirrhosis. Despite low rates of patients with undetectable HCV-RNA at weeks 4 and 8, all achieved a sustained virologic response at 12 weeks. These findings suggest that the time points to monitor HCV-RNA during DAA therapies and the treatment duration need to be optimized.