Viral kinetics and treatment response in patients with hepatitis C during induction and standard interferon therapy in combination with ribavirin

Community viral load and hepatitis C virus infection: Community viral load measures to aid public health treatment efforts and program evaluation

BACKGROUND

Hepatitis C virus (HCV) infection is the most prevalent blood-borne infection and causes more deaths than any other infectious disease in the US. Incident HCV infection in the US increased nearly 300 % between 2010 and 2015, Community viral load (CVL) measures have been developed for HIV to measure both transmission risk and treatment engagement in programs or areas.

OBJECTIVE

This paper presents a systematic review exploring the published literature on CVL constructs applied to HCV epidemiology and proposes novel CVL measures for HCV.

STUDY DESIGN AND SETTING

A systematic review was conducted of electronic databases; the search sought to identify published literature on HCV which discussed or applied CVL measures to HCV epidemiology. Novel CVL measures were constructed to apply to HCV.

RESULTS

No reports examining quantitative measures of HCV CVL were identified. Using the HIV CVL literature and the specific characteristics of HCV epidemiology, five HCV CVL measures are proposed. Narrower measures focusing on those engaged-in-care may be useful for program evaluation and broader measures including undiagnosed people may be useful for surveillance of HCV transmission potential.

CONCLUSION

Despite their potential value, CVL constructs have not yet formally been developed and applied to HCV epidemiology. The CVL measures proposed here could serve as valuable HCV program and surveillance measures. There is a need for informative surveillance measures to enhance policy and public health responses to achieve HCV control. Further study of these proposed HCV CVL measures to HCV epidemiology is warranted.

Managing chronic hepatitis C in the difficult-to-treat patient

Patients with chronic hepatitis C virus (HCV) infection and disease-related complications - among them cirrhosis and liver failure - pose a particular management challenge. Some of these patients may fail to respond to current therapy (non-responders), and some are affected so severely that treatment puts them at an unacceptable risk for complications. Treatment with pegylated interferon (peg-IFN) plus ribavirin improves hepatic enzyme levels and eradicates the virus in approximately 50% of patients; however, a significant number of patients do not respond to therapy or relapse following treatment discontinuation. Several viral, hepatic and patient-related factors influence response to IFN therapy; many of these factors cannot be modified to improve long-term outcomes. Identifying risk factors and measuring viral load early in the treatment can help to predict response to IFN therapy and determine the need to modify or discontinue treatment. Retreatment options for patients who have failed therapy are limited. Retreatment with peg-IFN has been successful in some patients who exhibit an inadequate response to conventional IFN treatment, particularly those who have relapsed. Consensus IFN, another option in treatment-resistant patients, has demonstrated efficacy in the retreatment of non-responders and relapsers. Although the optimal duration of retreatment and the benefits and safety of maintenance therapy have not been determined, an extended duration is likely needed. This article reviews the risk factors for HCV treatment resistance and discusses the assessment and management of difficult-to-treat patients.

Safety and efficacy of an induction dose of pegylated interferon alpha-2a on early hepatitis C virus kinetics in HIV/HCV co-infected patients: the CORAL-1 multicentre pilot study

To evaluate the safety and efficacy of an induction dose of pegylated interferon alpha 2a (IFN-alpha2a) on the 12-week hepatitis C virus (HCV) kinetics in human immunodeficiency virus (HIV) patients co-infected with HCV. One hundred sixteen HIV/HCV co-infected patients from nine hospitals in Spain were randomized to receive 270 microg/week of pegylated IFN-alpha2a for 4 weeks followed by 180 microg/week for 8 weeks or 180 microg/week for 12 weeks. Ribavirin was given at a daily dose of 1000 or 1200 mg. The main outcome measure was the percentage of patients achieving an HCV-RNA below 50 IU/mL or a decrease of 2 or more log(10) at week 12 (early virologic response, EVR). HCV-RNA was measured at baseline, weekly, for the first 4 weeks and monthly thereafter. We observed no difference in the percentage of patients achieving an EVR between arms (on-treatment, 74% in both arms; intention-to-treat, 70% in the induction arm and 67% in the control arm), nor were there differences in the percentage achieving an undetectable HCV qualitative polymerase chain reaction at any time points or in the decrease in HCV-RNA from baseline. No differences were found between arms in the percentage of dropouts (8% in the whole study population). Our study failed to find a benefit of an induction dose of 270 microg/week of pegylated IFN-alpha2a for 4 weeks on the EVR in co-infected patients who are treatment naive. Despite the lack of benefit with this regimen, induction therapy with this schedule was safe and well tolerated in co-infected patients.

Potent induction therapy with interferon and ribavirin combination therapy does not achieve a higher sustained virological response rate in chronic hepatitis C with genotype 1b and high hepatitis C virus RNA level

AIMS

To compare twice-daily interferon (IFN)-beta administration and once-daily IFN-alpha-2b administration as induction therapy in ribavirin combination therapy in chronic hepatitis C with a high viral load of genotype-1b hepatitis C virus (HCV).

METHODS

Sixty-one chronic hepatitis patients with a high viral load of genotype-1b HCV were randomly divided into three groups: group A was given IFN-beta 6 MU induction therapy twice daily for 2 weeks; group B was given IFN-alpha-2b 6 MU induction therapy once daily for 2 weeks; and group C was given no induction therapy. All three groups were then given IFN-alpha-2b 6 MU 3 days/week for the rest of the 24-week study period. Ribavirin was given for the entire 24-week study period.

RESULTS

Although the cumulative HCV-RNA negative rates tended to be higher in group A than in group B, the differencewas not significant. The HCV-RNA negative rate at week 2 was significantly higher in groups A and B than in group C (P < 0.05). The sustained virological response (SVR) rate was 16% overall, 21% for groups A and B, and 5% for group C; the SVR rate of groups A plus B tended to be higher than that of group C (P = 0.093).

CONCLUSIONS

There was no difference between the effects of the two induction therapies; potent induction therapy does achieve higher early viral clearance but not a higher SVR rate.

Hepatitis C virus RNA kinetics during the initial 12 weeks treatment with pegylated interferon-alpha 2a and ribavirin according to virological response

To optimize treatment of chronic hepatitis C early identification of patients who will not achieve a sustained virological response (SVR) is desirable. We investigated hepatitis C virus (HCV) RNA kinetics at day 1 (in 15 patients; genotypes 1 and non-1, 9 and 6 respectively) at weeks 1, 4 and 12 (in 53 patients; genotypes 1 and non-1, 19 and 34, respectively) during treatment with pegylated interferon alpha-2a and ribavirin. Patients with SVR had a significantly more pronounced mean log10 decline from baseline in HCV RNA levels at weeks 1 and 4 compared with patients who failed to achieve SVR (1.99 vs 0.85 at week 1, P = 0.0003 and 2.89 vs 1.72 at week 4, P = 0.0159), whereas no difference was noted after day 1. For patients with a 2-log10 decrease in HCV RNA levels at day 7, the positive predictive value (PPV) for a SVR was 92%, whereas week 12 was the best time point for predicting a later nonresponse [negative predictive value (NPV) 92%] in patients failing to achieve a 2-log10 drop. For patients with genotype non-1 and a 2-log10 decrease in HCV RNA levels the PPV for a SVR was 89% week 1, and 79% weeks 4 and 12. The corresponding NPV for patients with genotype non-1 were 43, 40 and 100% respectively. During treatment with pegylated interferon alpha-2a plus ribavirin the HCV RNA decline at week 1 was an accurate predictor of SVR in patients who had achieved a 2-log10 drop in HCV RNA levels, whereas the lack of such decline week 12 was an accurate marker of a nonresponse.

Early viral kinetics and treatment outcome in combination of high-dose interferon induction vs. pegylated interferon plus ribavirin for naive patients infected with hepatitis C virus of genotype 1b and high viral load

An investigation was carried out to determine whether early viral monitoring could predict efficiently the virological response to combination therapy of two different regimens in treatment-naive chronic hepatitis C patients infected with genotype 1b with high baseline viral load. Patients were randomly assigned to receive interferon (IFN) alpha-2b induction (6 MU daily for 2 weeks) followed by 6 MU thrice weekly for 46 weeks (IFN/R group; n = 20), or pegylated IFN alpha-2b (1.5 microg/kg) weekly for 48 weeks (PEG/R group; n = 28), in combination with ribavirin (600-1,000 mg daily). Serum HCV RNA was quantitated at 0, 6, 12, 24, and 48 hr post-dose, weekly during the first 4 weeks, and thereafter viral kinetics were assessed every 4 weeks. The sustained virological response rates in the IFN/R and PEG/R groups were 40% (8/20) and 43% (12/28), respectively. The non-virological response rates were 40% (8/20) and 39% (11/28), respectively. The cumulative virological response rates were similar in both groups. Multivariate analyses identified no independent baseline variables linked to sustained virological or non-virological response. Early log viral load changes from baseline in both groups were significantly greater at all time-points after 24 hr in virological response patients than in non-virological response patients (P < 0.001 for all). On the receiver operating characteristics curves for prediction of non-virological response, the area under the curves (0.951-1.000), sensitivity (90%-100%), and negative predictive value (96%- 100%) were similar at any time-points after 24 hr. For prediction of sustained virological response, sensitivity of 80% with 86% negative predictive value was observed for negative HCV RNA at week 12, with the highest area under the curves value of 0.919. The results suggest that early monitoring of viral kinetics is a useful measure to predict virological response, and might facilitate development of rational and effective therapeutic strategies.

Interferon alfa2a induction therapy in combination with ribavirin and amantadine for the treatment of naive patients with chronic HCV infection

Pilot studies have suggested that the addition of amantadine to interferon (IFN) is effective against hepatitis C virus (HCV). Furthermore, IFN induction therapy seems to improve virological response rates. In this open, randomized, multicentre trial we compared safety and efficacy of a triple therapy comprising IFN alpha 2a, ribavirin and amantadine using high induction doses (6 MU IFN alpha daily for the first 6 weeks) against a therapy with standard IFN alpha dosages over the entire treatment period plus amantadine and ribavirin. A total of 158 naive patients with chronic HCV infection were randomized 1:1. Group A (n = 81): induction therapy with 6 MU IFN alpha daily for 6 weeks, followed by 6 MU three times a week (tiw) for 18 weeks and then 3 MU tiw until week 48. Group B (n = 77): standard therapy with 6 MU IFN alpha tiw for 24 weeks, followed by 3 MU until week 48. All patients received oral ribavirin (10 mg/kg/day) and amantadine (200 mg/day). The triple therapy was safe and well tolerated. There were no significant differences between the groups with respect to biochemical response rates. Groups A and B did not differ in virological response rates at the end of treatment (33%vs 35%) or at the end of the 6 month follow up period (37%vs 39%). We could not detect favourable effects on sustained virological response rates using induction therapy, in either genotype 1 or non-1 infected patients. In summary, induction therapy with 6 MU IFN alpha daily did not result in increased overall response rates compared with standard IFN alpha dosages of 6 MU tiw.