Treatment of chronic he1patitis C genotype 1 with peginterferon-alpha2a (40 kDa) plus ribavirin under routine clinical practice in Spain: early prediction of sustained virological response rate

High Response Rate to Pegylated Interferon Alpha and Ribavirin Combination Therapy in Hemophilic Children with Chronic Hepatitis C; A Case-Control Study

Scarce data is available on the efficacy of Pegylated Interferon (Peg-IFN) and Ribavirin (RBV) combination therapy in hemophilic children with chronic hepatitis C. The aim of this study was to evaluate the efficacy of Peg-IFN and RBV combination therapy for hemophilic children infected with hepatitis C virus (HCV) in comparison with adult hemophilic patients with chronic hepatitis C. A case-control study comprised 31 pediatric hemophilic patients ages under 16 years with previously untreated HCV genotype-1 or -3 infection as the case group and 62 treatment naive adult hemophilic patients with chronic HCV infection as the control group. Case and control groups were matched case by case according to HCV genotype, HCV RNA level and rs12979860 polymorphism. All patients in the case and control groups were treated with Peg-IFN and RBV for 24-48 weeks according to HCV genotype. Sustained virological response (SVR) was achieved in 26 (83.9%) pediatric patients and in 39 (62.9%) of adult patients (P = 0.05, OR = 3.07, 95%CI = 1.03-9.09). The rate of SVR was not different according to HCV genotype, HCV RNA level, and rs12979860 polymorphism in both studied groups whereas achieving early virological response was associated with achievement of SVR in both groups. The efficacy of Peg-IFN and RBV combination therapy in hemophilic children with chronic hepatitis C is higher than that of adult hemophilic patients.

SVR12 is higher than SVR24 in treatment-naïve hepatitis C genotype 1 patients treated with peginterferon plus ribavirin

BACKGROUND

Randomized clinical trials (RCTs) of interventions for the hepatitis C virus have historically used sustained virological response (SVR) at 24 weeks after treatment (SVR24) as the key effect measure. However, recent RCTs investigating the efficacy of new direct acting agents (DAAs) have used SVR at 12 weeks after treatment (SVR12). While there is evidence to suggest SVR24 and SVR12 are similar in patients receiving new DAAs, this is unlikely to be true for patients receiving backbone peginterferon-ribavirin control treatment. Establishing the difference between SVR12 and SVR24 for patients receiving peginterferon-ribavirin treatment is therefore necessary to avoid biased interpretations of the benefits of newer DAAs.

METHODS

We searched the MEDLINE®, Embase™, and Cochrane CENTRAL for RCTs with a peginterferon-ribavirin arm that used SVR24 and/or SVR12. As no RCTs reported on both, we pooled SVR12 and SVR24 proportions using conventional meta-analysis. Proportions were pooled separately for peginterferon alpha-2a and alpha-2b. Further, a Bayesian meta-regression model was employed to estimate the difference between SVR12 and SVR24.

RESULTS

Thirty-five RCTs including a peginterferon arm were identified. Twenty-four trials included a peginterferon alpha-2a plus ribavirin arms, of which 20 reported SVR24 and five reported SVR12. Seventeen trials included a peginterferon alpha-2b plus ribavirin arm, of which 16 reported SVR24 and one reported SVR12. Using Bayesian meta-regression, the pooled SVR12 was 6% higher than SVR24 with peginterferon alpha-2a (53% versus 47%) and 5% higher with peginterferon alpha-2b (45% versus 40%) and 95% credible intervals (CrIs) were only marginally overlapping. The meta-regression also demonstrated a marginally significant relative risk of 1.13 (95% CrI 0.99-1.26) of SVR12 versus SVR24. The conventional pairwise meta-analyses were consistent with these findings.

CONCLUSION

Considering the relatively large difference observed between SVR12 and SVR24, it seems reasonable to insist that future clinical trials report both to allow for complete transparency and clarity in their interpretation.

Differences in clinical outcomes among hepatitis C genotype 1-infected patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin: a meta-analysis

Background

With the development of new direct acting antiviral (DAA) therapy for hepatitis C, the backbone peginterferon alpha used may be of importance in maximizing treatment outcomes. To this end, the rates of sustained virologic response (SVR), relapse, and treatment discontinuation among hepatitis C genotype 1-infected patients given peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin were determined using a meta-analysis.

Methods

Randomized trials examining peginterferon alpha-2a or peginterferon alpha-2b co-administered with ribavirin for 48 weeks were included. Data were extracted on SVR, relapse, and treatment discontinuations for treatment-naïve and treatment-experienced patients. Pooled proportions using fixed and random effects meta-analysis were calculated.

Results

Twenty-six trials provided data on patients treated with peginterferon alpha-2a plus ribavirin, and 19 trials provided data on patients treated with peginterferon alpha-2b plus ribavirin. Five trials were direct head-to-head evaluations. In the subset of trials that included head-to-head evaluations, no significant differences were observed between the two treatments for treatment-naïve (relative risk [RR]: 1.07, 95% confidence intervals [CI]: 0.97–1.18) and treatment-experienced patients (RR: 1.27, 95% CI: 0.58–2.77). Using only active trial arms, a larger proportion of the treatment- naïve patients who were provided peginterferon alpha-2a plus ribavirin achieved a SVR (47%), which is greater than that of treatment-naïve patients who were provided peginterferon alpha- 2b plus ribavirin (40% SVR achievement); however, a larger proportion of treatment- experienced patients who were provided peginterferon alpha-2b plus ribavirin achieved a SVR (16%) when compared with treatment-experienced patients given peginterferon alpha-2a plus ribavirin (12% SVR achievement). A larger proportion of relapses occurred among both treatment-naïve and treatment-experienced patients given peginterferon alpha-2a plus ribavirin, when compared with treatment-naïve and treatment-experienced patients taking peginterferon alpha-2b plus ribavirin. The proportion of patients discontinuing treatment was greater among treatment-naïve patients taking peginterferon alpha-2a plus ribavirin, but smaller among treatment-experienced patients.

Conclusion

There are small differences in treatment outcomes for different types of peginterferon- alpha. Patient status and complexity of administration may differentiate clinical outcomes.

Estimating the likelihood of sustained virological response in chronic hepatitis C therapy

The likelihood of a sustained virological response (SVR) is the most important factor for physicians and patients in the decision to initiate and continue therapy for chronic hepatitis C (CHC) infection. This study identified predictive factors for SVR with peginterferon plus ribavirin (RBV) in patients with CHC treated under 'real-life' conditions. The study cohort consisted of patients from a large, retrospective German multicentre, observational study who had been treated with peginterferon alfa-2a plus RBV or peginterferon alfa-2b plus RBV between the years 2000 and 2007. To ensure comparability regarding peginterferon therapies, patients were analysed in pairs matched by several baseline variables. Univariate and multivariate logistic regression analyses were used to determine the effect of nonmatched baseline variables and treatment modality on SVR. Among 2378 patients (1189 matched pairs), SVR rates were 57.9% overall, 46.5% in HCV genotype 1/4-infected patients and 77.3% in genotype 2/3-infected patients. In multivariate logistic regression analysis, positive predictors of SVR were HCV genotype 2 infection, HCV genotype 3 infection, low baseline viral load and treatment with peginterferon alfa-2a. Negative predictors of SVR were higher age (≥40 years), elevated baseline gamma-glutamyl transpeptidase (GGT) and low baseline platelet count (<150,000/μL). Among patients treated with peginterferon plus RBV in routine clinical practice, genotype, baseline viral load, age, GGT level and platelet levels all predict the likelihood of treatment success. In patients matched by baseline characteristics, treatment with peginterferon alfa-2a may be a positive predictor of SVR when compared to peginterferon alfa-2b.

Controlled release recombinant human interferon-α2b for treating patients with chronic hepatitis C genotype 1: a phase 2a clinical trial

Better convenience and tolerability and sustained therapeutic concentrations might improve interferon (IFN) treatment for chronic hepatitis C virus (HCV) infection. In an open-label, randomized study, controlled release free (chemically unmodified) recombinant human IFN-α(2b) in poly(ether-ester) microspheres (CR-rhIFN-α(2b)), was injected at doses of 160, 320, 480 or 640 μg every 2 weeks for 12 weeks with concomitant weight-based oral ribavirin in 32 treatment-naïve patients with chronic HCV genotype 1. Treatment was well tolerated, with 31 patients (97%) successfully completing the study. Full doses of CR-rhIFN-α(2b) were administered on 96% of scheduled occasions. Flu-like symptoms were generally mild and brief. Injection site reactions developed in 13 patients (41%), and neutropenia occurred in six of eight patients receiving 640 μg. In the 320, 480 and 640 μg groups, 62-75% of patients achieved a ≥2 log(10) HCV RNA reduction by 4 weeks and 88-100% by 12 weeks. For those groups, the pooled median time to ≥2 log(10) reduction was 11 days (95% confidence interval, 7-35 days). In those groups, viral reduction below the limit of detection was accomplished in 25% of patients by 4 weeks and in 62% by 12 weeks. The 160-μg dose was less potent. After CR-rhIFN-α(2b) injection, stable plateau levels of serum IFN-α(2b) were generally reached within 72 h. Treatment-emergent neutralizing antibodies to IFN-α(2b) were observed in one patient. No antibodies to host plant proteins were detected. CR-rhIFN-α(2b) with ribavirin cotherapy was well tolerated and displayed potent early antiviral activity in patients with chronic HCV genotype 1.

Individualized treatment of chronic hepatitis C with pegylated interferon and ribavirin

Chronic infection with hepatitis C virus (HCV) is a major public health problem, with perhaps 180 million people infected worldwide. A significant proportion of these will eventually develop clinical complications, such as cirrhosis, liver decompensation and hepatocellular carcinoma. Sustained virological response (SVR) to antiviral therapy is associated with improvement in liver histology and survival free of liver-related complications. Great effort has been made to improve SVR rate by adapting the duration of therapy according to HCV genotype and to on-treatment response. Rapid virological response (RVR, undetectable HCV RNA at week 4) usually has a high positive predictive value for achieving SVR and early virological response (EVR, ≥ 2 log reduction or undetectable HCV RNA at week 12) exhibits a high negative predictive value for non-response. Individualized approach can improve cost-effectiveness of HCV antiviral therapy by reducing side effects and the costs of therapy associated with unnecessary exposure to treatment and through extending therapy for those with unfavorable features. This article summarizes recent data on strategies of individualized treatment in naïve patients with mono-infection by the different HCV genotypes. The management of common side effects, the impact of HCV infection on health-related quality of life and the potential applications of host genomics in HCV therapy are also briefly discussed.

[Treatment of hepatitis C virus infection: current status and perspectives]

Current treatment of patients with chronic hepatitis C consists of pegylated interferon and ribavirin. The application of viral kinetics is currently allowing treatment to be optimized by varying the length of treatment to 24 weeks for genotypes 2 and 3 and 48 weeks for the remaining genotypes. Thus, patients with genotype 1, with a low viral load, and rapid virological response (RVR) obtain a high RVS with 24 weeks' treatment. In contrast, slow responders may benefit from 72 weeks' treatment. Patients with genotypes 2 and 3 can also benefit from regimens designed according to viral kinetics. Higher doses and more prolonged periods have been tested in non-responders to current treatment, although for many, the only option is to wait for a new generation of drugs. Maintenance therapy with low-dose interferon to prevent cirrhosis and hepatocarcinoma is currently being evaluated.

[Results of pegylated interferon and ribavirin for the treatment of chronic hepatitis C in clinical practice: a 5-year experience]

INTRODUCTION

Numerous clinical trials have demonstrated the efficacy of treatment with pegylated interferon and ribavirin but little is known about the results obtained in clinical practice.

OBJECTIVE

To evaluate treatment response and factors influencing the treatment of chronic hepatitis C in clinical practice.

MATERIAL AND METHODS

Between August 2001 and December 2005, we treated 219 patients with pegylated interferon (alpha 2a -fixed dose, or alpha 2b, according to weight) and ribavirin. Patients with genotype 1 or 4 received treatment with pegylated interferon alpha 2a (180 microg/week) and ribavirin (1000 mg/day if body weight was <75 kg or 1200 mg/day if body weight was >75 kg) or interferon alpha 2b (1.5 microg/kg/week) and ribavirin (10.6 mg/kg/day) for 48 weeks. Patients with genotype 2 or 3 were treated for 24 weeks with the same regimen of pegylated interferon alpha-2a or alpha-2b, but with 800 mg of ribavirin divided in two daily doses. Sustained viral response was defined as absence of HCV-RNA 6 months after the end of treatment.

RESULTS

A total of 219 patients were included (69% men; mean age 44+/-10). As epidemiological antecedents, 22.4% of the treated patients had previously consumed drugs parenterally and 22.4% had received blood transfusions before 1992. Forty-seven percent of the patients with liver biopsy had fibrosis bridges or established liver cirrhosis. The genotype was distributed as follows: 69.8% genotype 1, 4.1% genotype 2, 17.8% genotype 3, and 8.2% genotype 4. Of the 219 patients, 76 (35%) were treated with pegylated interferon alpha 2a and 143 (65%) with interferon alpha 2b. Analysis of response by genotype revealed that sustained viral response was obtained in 46% genotype 1, 88.9% genotype 2, 78.9% genotype 3, and 33.3% genotype 4. Univariate analysis showed that the only variable influencing sustained viral response was genotype.

CONCLUSION

Treatment with pegylated interferon and ribavirin in clinical practice shows a similar pattern of sustained viral response to that obtained in clinical research. The main variable correlated with sustained viral response continues to be viral genotype.