The impact of ribavirin plasma concentration on the efficacy of the interferon-sparing regimen, sofosbuvir and ribavirin

Sofosbuvir-based therapies in genotype 2 hepatitis C virus cirrhosis: A real-life experience with focus on ribavirin dose

This study aimed to investigate the efficacy and safety of sofosbuvir-based therapies for the treatment of cirrhosis from hepatitis C virus (HCV) genotype 2 infection. Data of all consecutive HCV genotype 2 cirrhotic patients who started sofosbuvir-based treatments between January 2015 and March 2017 in eight Italian tertiary hospitals were collected retrospectively. Overall, 273 patients (Child A: 94.5%) were enrolled. In the 194 subjects treated with sofosbuvir/ribavirin, median initial ribavirin dosage was 13.9 mg/kg/day, and therapy duration was 16 weeks. Sustained virological response (SVR) rates were 93.8% in intention-to-treat (ITT) and 95.3% in per-protocol (PP) analyses for the 129 treatment-naïve patients, and 96.9% (ITT) and 98.4% (PP) for the 65 treatment-experienced subjects. Adverse events were reported in 142 patients (73.2%), but only 1.5% discontinued treatment. Eighty-eight subjects with treatment-induced anemia (mild: 34.5%, moderate: 7.7%, severe: 3.1%) had to reduce ribavirin dosage, but SVR rates were comparable to the weight-based dose group, both in ITT (95.4% and 94.3%) and PP (97.7% and 95.2%) analyses, respectively. Moreover, ITT and PP SVR rates were similar between shorter (<20 weeks) (94.1% and 96.0%, respectively) and prolonged (≥20 weeks) regimens (95.7% and 96.7%, respectively). SVR rates in the 79 subjects treated with sofosbuvir/daclatasvir (without ribavirin) were similar (ITT: 96.2%; PP: 97.4%, respectively), without de novo/worsening anemia. In conclusion, in a real-life study centered on genotype 2 patients with well-compensated cirrhosis, sofosbuvir-based regimens were associated with good SVR and tolerability rates, regardless of previous antiviral treatments, without a significant impact of on treatment ribavirin dose reductions.

Ribavirin steady-state plasma level is a predictor of sustained virological response in hepatitis C-infected patients treated with direct-acting antivirals

BACKGROUND

In the era of highly effective direct-acting antivirals (DAAs) for treatment of patients with chronic hepatitis C virus (HCV) infection, ribavirin (RBV) is still considered beneficial in certain patients.

AIM

To assess the association between RBV steady-state plasma levels and sustained virological response (SVR).

METHODS

Consecutive HCV-infected patients treated with DAAs plus RBV from four Dutch academic medical centres were enrolled. RBV steady-state plasma levels were prospectively measured at treatment week 8 using validated assays. Logistic regression analyses were performed to assess the influence of RBV steady-state plasma level on SVR, and RBV therapeutic range was explored using area under the ROC curve analyses.

RESULTS

A total of 183 patients were included, of whom 85% had one or more difficult-to-cure characteristics (ie treatment experienced, HCV genotype 3, cirrhosis). The majority was treated with a sofosbuvir-based regimen and 163 (89%) patients achieved SVR. Median RBV dose was 12.9 (interquartile range 11.2-14.7) mg/kg/d, and median RBV steady-state plasma level was 2.66 (1.95-3.60) mg/L. In multivariable analyses, higher RBV steady-state plasma level (adjusted odds ratio 1.79 [95% CI 1.09-2.93]) was an independent predictor of SVR. With regard to the optimal RBV therapeutic range, 2.28 mg/L was the optimal lower cut-off for achieving SVR and 3.61 mg/L was the upper cut-off for preventing significant anaemia (Haemoglobin < 10 g/dL).

CONCLUSION

In this cohort of mainly difficult-to-cure patients treated with DAAs plus RBV, higher RBV steady-state plasma level was an independent predictor of SVR.

Diagnostics in hepatitis C: The end of response-guided therapy?

On-treatment hepatitis C virus (HCV) RNA has been used to predict response to interferon (IFN)-based therapy. The concept of response-guided treatment (RGT) was established to determine optimal treatment duration and to early identify patients not responding to futile therapies. RGT helped to improve sustained virologic response (SVR) rates and lower the rates of adverse effects. RGT was of particular importance for telaprevir- and boceprevir-based triple therapies. RGT strategies are dependent on highly sensitive and reproducible HCV RNA quantification. However, different HCV RNA assays are used in routine clinical practice and these differ significantly in their performance characteristics. The development of IFN-free therapies has fundamentally changed the role of on-treatment HCV RNA for SVR prediction. Given the high efficacy and excellent tolerability of IFN-free regimens, the interest in treatment individualization has decreased. However, shorter treatment durations may still be desirable, particularly with respect to the high costs of current IFN-free direct-acting antiviral agents (DAAs). Moreover, some difficult-to-treat patients remain, e.g., those infected with HCV genotype 3 in whom the current standard of care may not always be sufficient to achieve SVR, especially in treatment-experienced patients with cirrhosis. Here, a RGT extension may be feasible. However, current data on the predictive value of on-treatment HCV RNA are limited and have shown conflicting results. As more potent DAAs become available, the role of response prediction may diminish further. Currently, shorter treatment duration is only based on baseline HCV RNA whereas no RGT strategy is recommended for any of the approved DAA regimens available.