The very-rapid and the ultra-rapid virologic response to two treatment options in patients with chronic hepatitis C: an interim report of a prospective randomized comparative effectiveness study

Rapid virologic response in chronic hepatitis C genotype 1: Evaluation of pretreatment factors in patients

BACKGROUND AND STUDY AIMS

Rapid virologic response (RVR) is defined as undetectable hepatitis C virus (HCV) RNA in serum after 4 weeks of treatment for chronic hepatitis C (CHC). Paritaprevir/ritonavir/ombitasvir (PRO) and/or dasabuvir (D), with or without ribavirin [PRO (D) ± ribavirin], which are direct-acting antivirals (DAAs), is the currently approved treatment regimen for CHC genotype 1; this regimen can also be used in patients with end-stage renal failure (ESRF). In this study, we aimed to evaluate the effect of pretreatment factors on RVR in patients treated with PRO (D) ± ribavirin.

PATIENTS AND METHODS

This study included 60 patients with CHC genotype 1 who were treated with PRO (D) ± ribavirin and achieved RVR. Patients' demographic data; baseline HCV RNA levels; HCV genotype information; biochemical, histologic, and radiologic results; and previous treatment history were recorded. Patients were categorized into two groups: virologic responses achieved in the first week (group 1) and in the first to the fourth week (group 2). Pretreatment factors were compared between the groups.

RESULTS

Patients in group 1 who achieved ultraRVR (undetectable HCV RNA after 1 week of treatment) had significantly lower mean pretreatment HCV RNA levels and lower prevalence of ESRF than patients in group 2.

CONCLUSIONS

RVR has been indicated to be a robust positive predictor of sustained virologic response. We concluded that some pretreatment factors such as low HCV RNA level and absence of ESRF might lead to faster RVR and shorter treatment duration with DAAs for CHC.

Very rapid virologic response and early HCV response kinetics, as quick measures to compare efficacy and guide a personalized response-guided therapy

BACKGROUND

This is the second and final report for our study designed to compare two generic sofosbuvir products for the degree and speed of virologic response to a dual anti-hepatitis C virus (HCV) treatment protocol. We aimed to test the applicability of the early virus response kinetics and the very rapid virologic response (vRVR) rate as quick outcome measures for accelerated comparative efficacy studies and as a foundation for a personalized response-guided therapy.

METHODS

Fifty eligible chronic HCV patients were randomized to either one of two generic sofosbuvir products (Gratisovir or Grateziano) at a daily dose of one 400 mg tablet plus a weight-based ribavirin dose. Data were compared between the groups for early virus response kinetics and vRVR rates in relation to the rates of final sustained virologic response at week 12 posttreatment (SVR12).

RESULTS

The Log10 transformed virus load (Log polymerase chain reaction) curves showed fairly similar rapid decline during the first 2 weeks, with no significant difference between the groups at four analysis points throughout the study by repeated-measures factorial analysis of variance test (P=0.48). The SVR12 rates were 96% (95% confidence interval, 79.6%-99.9%) in Gratisovir group (24/25) and 95.7% (95% confidence interval, 78%-99.9%) in Grateziano group (22/23). There was no statistically significant difference found by exact test (P>0.999). There was a significant association between the vRVR and the SVR12, with 100% positive predictive value (38/38 of those who had vRVR, achieved a final SVR12) and 82.6% sensitivity (among the total 46 with SVR12, 38 were having vRVR).

CONCLUSION

We can conclude from our study that the early HCV response kinetics and the vRVR rates could be used as sensitive quick markers for efficacy (with a very high positive predictive value for SVR12), based on our accelerated comparative efficacy research model. This might open the way for new models of accelerated equivalence efficacy studies along with the bioequivalence kinetics studies to test a generic drug against a reference. Also, the early response kinetics and the vRVR might be used as qualifiers for a personalized course of treatment. This could shorten unnecessarily long treatment courses in rapid responders and might help to avoid relapses in slow responders.