Treatment with pegylated interferon and ribavarin in HCV infection with genotype 2 or 3 for 14 weeks: a pilot study

Different viral kinetics between hepatitis C virus genotype 1 and 2 as on-treatment predictors of response to a 24-week course of high-dose interferon-alpha plus ribavirin combination therapy

To elucidate the genotype-specific virus-host-drug interaction and the on-treatment viral kinetics in predicting sustained virologic response (SVR), serial serum hepatitis C virus (HCV) ribonucleic acid (RNA) levels at baseline, treatment week 2 (W2), treatment week 4 (W4), and treatment week 12 (W12) were measured in 199 chronic HCV-infected Taiwanese patients receiving interferon-alpha (INF-alpha) 6 million units (MU) three times weekly plus 1000 to 1200 mg/day of ribavirin for 24 weeks. The SVR rate was 90.5% (95/105) for HCV genotype 2 (HCV-2) patients and 47.9% (45/94) for HCV-1 patients (P < 0.0001). HCV-2 patients had a significantly higher rate of rapid virologic response (RVR) at W2 than HCV-1 patients. HCV RNA negativity at W4 had the highest accuracy of prediction (80%) of SVR with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 81%, 79%, 78%, and 82%, respectively, for HCV-1 patients. HCV RNA negativity or 2 logs drop at W4 had the highest accuracy of prediction (92%) with sensitivity, specificity, PPV, and NPV of 100%, 20%, 92%, and 100%, respectively, for HCV-2 patients. In multivariate analysis, the significant factors associated with SVR in HCV-1 patients were HCV RNA negativity at W12 and W4. HCV RNA negativity or 2 logs drop was the only significant factor associated with SVR in HCV-2 patients. In conclusion, a RVR at W4 could predict an SVR with a high degree of accuracy to a 24-week course of high-dose IFN/ribavirin for both HCV-1 patients and HCV-2 patients. With respect to each HCV genotype, the on-treatment virologic responses are the most important factors associated with SVR.

Peginterferon-alfa2a plus ribavirin for 48 versus 72 weeks in patients with detectable hepatitis C virus RNA at week 4 of treatment

BACKGROUND & AIMS

Patients with chronic hepatitis C who do not respond rapidly to therapy have a low chance of developing a sustained virologic response (SVR) when treated for 48 weeks. This study investigated whether treatment for 72 weeks increases the rate of SVR in patients with detectable hepatitis C virus (HCV)-RNA levels at week 4 of treatment.

METHODS

A total of 510 treatment-naive patients were treated with peginterferon-alfa2a (180 microg/wk) plus ribavirin (800 mg/day). Patients with detectable HCV-RNA levels at week 4 (n = 326) were randomized to complete 48 (group A, n = 165) or 72 weeks (group B, n = 161) of treatment. Patients with undetectable HCV-RNA levels at week 4 (n = 184) were allocated into group C (n = 148) or group D (n = 36), according to HCV genotype and baseline viremia, and treated for 24 or 48 weeks, respectively. All patients were followed-up for 24 weeks after the end of treatment.

RESULTS

The end-of-treatment response rate (61%) was similar in groups A and B, but the SVR rate was higher in group B (45% vs 32% in A; P = .01). In genotype 1-infected patients randomized to group A (n = 149) or B (n = 142), SVR rates were 28% and 44%, respectively (P = .003). The incidence of adverse events was similar in all groups. Treatment discontinuation was more frequent in group B (36%) than in group A (18%) (P = .0004). SVR rates in groups C and D were 79% and 64%, respectively.

CONCLUSIONS

Extension of treatment with peginterferon-alfa2a plus ribavirin from 48 to 72 weeks significantly increases the rate of SVR in patients with detectable viremia at week 4 of treatment.

A study of low dose peginterferon alpha-2b with ribavirin for the initial treatment of chronic hepatitis C

PURPOSE

A prospective randomized trial was undertaken to test the efficacy of low and standard doses of pegylated interferon alpha-2b in combination with ribavirin for the initial treatment of chronic hepatitis C. By nature of its design the study also provided data on response to therapy over a spectrum of doses of both pegylated interferon alpha-2b and ribavirin calculated on a body weight basis.

SUBJECTS AND METHODS

Fifty micrograms of pegylated interferon alpha-2b or 100 microg for patients weighing<75 kg or 150 microg for patients>or=75 kg were administered weekly with 1000 mg ribavirin daily for 48 wk if serum hepatitis C virus (HCV) RNA was undetectable after the first 24 wk of therapy.

RESULTS

Overall sustained viral response (SVR) was 45% for standard dose and 33% for low dose, p=0.02. For genotypes 2 and 3 SVR was 65% for standard dose, and 56% for low dose, p=0.51. For genotype 1 SVR was 38% for standard dose, and 24% for low dose, p=0.03. For genotype 1 patients whose doses exceeded the 1-2-5 threshold, that is >or=1.25 microg/kg body weight pegylated interferon alpha-2b weekly and >or=12.5 mg/kg body weight ribavirin daily, SVR was 51%.

CONCLUSION

The results of this study underscore the importance of adequate dosing of ribavirin as well as pegylated interferons in achieving an SVR when treating genotype 1 chronic hepatitis C patients with combination therapy.

Anti-HCV therapies in chimeric scid-Alb/uPA mice parallel outcomes in human clinical application

Compounds with in vitro anti-hepatitis C virus (HCV) activity are often advanced directly into clinical trials with limited or no in vivo efficacy data. This limits prediction of clinical efficacy of compounds in the HCV drug pipeline, and may expose human subjects to unnecessary treatment effects. The scid-Alb-uPA mouse supports proliferation of transplanted human hepatocytes and subsequent HCV infection. Cohorts of genotype 1a HCV-infected mice were treated with interferon alpha-2b(IFN-alpha), BILN-2061 (anti-NS3 protease), or HCV371 (anti-NS5B polymerase). Mice treated with 1350 IU/g/day IFN-alpha intramuscularly for 10 to 28 days demonstrated reduced viral titers compared with controls in all five experiments (P < .05, t test); viral titers rebounded after treatment withdrawal. A more pronounced antiviral effect with IFN-alpha was seen in genotype 3a-infected mice. Pilot studies with BILN2061 confirmed exposure to 10X replicon EC50 at trough and reduced viral titer over 2 log at 4 days. In a second 7-day study, mean HCV RNA titers dropped 1.1 log in BILN2061-treated animals, 0.6 log in IFN-treated mice, and rose 0.2 log in controls (P = .013, ANOVA). Pre-existing mutants with partial resistance to BILN2061 were identified by sequencing both the human inoculum and sera from treated mice. The polymerase inhibitor HCV371 yielded a decline in HCV titers of 0.3 log relative to vehicle-treated controls (P = NS). Performance of all three antiviral regimens in the chimeric mouse model paralleled responses in humans. In conclusion, this system may help selection of lead compounds for advancement into human trials with an increased likelihood of clinical success while broadening the tools available for study of the biology of HCV infection.

Chronic hepatitis C virus infection: genotyping and its clinical role

Chronic hepatitis C virus (HCV) infection is a worldwide public health problem with a global prevalence of 2%. A high proportion of those infected are at risk of developing cirrhosis and hepatocellular carcinoma and modeling data predicts that the burden of disease could soon increase substantially. The liver disease associated with chronic infection has led investigators to look for correlates between viral properties and disease progression, severity of disease and the response to antiviral therapy. HCV has been classified into six genotypes but genotype does not appear to influence disease presentation or severity of disease. However, genotype has been identified as a major predictor of response to interferon-based antiviral therapy. Antiviral regimens have been optimized for infections with HCV genotypes 1-4, although treatment strategies for genotypes 5 and 6 have yet to be developed. The molecular basis for the differences in response of HCV genotypes has yet to be determined.

Update on viral hepatitis: 2005

PURPOSE OF REVIEW

This review aims to provide a concise summary of relevant developments in the treatment and prevention of viral hepatitis based on publications between December 2004 and November 2005.

RECENT FINDINGS

Long-term therapy with lamivudine was shown to reduce the incidence of adverse clinical outcomes in patients with chronic hepatitis B. This benefit was, however, diminished in patients with viral breakthrough. Combination therapy (peginterferon or telbivudine plus lamivudine) decreased the risk of antiviral resistance but did not improve response compared with monotherapy. Entecavir and tenofovir were shown to be effective in suppressing lamivudine-resistant hepatitis B. A shorter duration of peginterferon-ribavirin treatment was shown to be feasible in genotype 2/3 hepatitis C patients. Relapsers to previous standard interferon-based therapy had higher sustained virological response rates than previous non-responders when retreated with peginterferon-ribavirin. Hepatitis C patients with advanced liver disease may achieve sustained virological response with peginterferon-ribavirin treatment, but the complication rate was high.

SUMMARY

New insights into the management of viral hepatitis have been gained over the past year. The problem of antiviral resistance in chronic hepatitis B is real and treatment options need to keep evolving. Advances have been made in hepatitis C treatment including patients with genotypes 2 or 3 infection and decompensated cirrhosis.

Duration of peginterferon therapy in acute hepatitis C: a randomized trial

Spontaneous resolution of acute hepatitis C virus infection cannot be predicted, and chronic evolution of the disease occurs in a majority of cases. To assess the efficacy and safety of peginterferon alpha-2b administered for 8, 12, or 24 weeks in patients with acute hepatitis C virus infection a total of 161 patients were identified with acute hepatitis C virus infection. Of these, 30 patients refused treatment but were retained in the study as a nonrandomized comparison group. Of the 131 patients who consented to treatment, 29 patients spontaneously resolved, leaving 102 patients randomly assigned to peginterferon alpha-2b (1.5 microg/kg) for 8 weeks (group A; n=34), 12 weeks (group B; n=34), and 24 weeks (group C; n=34). The primary end point was sustained virologic response. An intent-to-treat analysis was used for efficacy and safety end points. Sustained virologic response was achieved in 23/34 (67.6%), 28/34 (82.4%), and 31/34 (91.2%) of patients in groups A, B, and C, respectively; all had undetectable hepatitis C virus RNA 48 weeks after the end of therapy. Treatment for 8 or 12 weeks was effective in genotypes 2, 3, and 4, whereas genotype 1 required 24 weeks of therapy. The 8- and 12-week regimens were associated with fewer adverse events compared with the 24-week regimen. In conclusion, peginterferon alpha-2b effectively induces high sustained virologic response rates in patients with acute hepatitis C virus infection, thus preventing development of chronic hepatitis C. Duration of treatment should be further optimized based on genotype and rapid virologic response at week 4.

Review article: predicting response in hepatitis C virus therapy

The introduction of combination therapy with ribavirin and of pegylated interferons has improved treatment results in patients with chronic hepatitis C. However, overall rates of sustained virologic response following antiviral therapy of chronic hepatitis C still do not exceed 54-63%. Because of several virus- and patient-related factors, treatment is even less successful in some patient subpopulations. The major viral factors associated with impaired response are hepatitis C virus genotype 1 infection and a high viral load. Among patient-related factors cirrhosis is of special importance. Baseline predictive factors for sustained virologic response become less important for prediction of treatment outcome when quantifications of hepatitis C virus RNA during early therapy are taken into account. This article provides a summary of virus- and patient-related parameters, which are prognostic for response to antiviral therapy in chronic hepatitis C and focuses on the prediction of treatment response by quantification of hepatitis C virus RNA concentration during therapy.

[Individualised treatment of chronic hepatitis C]

Patients infected with HCV genotype 1 are treated with a pegylated interferon plus ribavirin for 48 weeks, while HCV-2 or 3 infected patients are treated for 24 weeks. Knowledge of the HCV genotype and fibrosis stage together with baseline viremia and the initial virologic response to therapy enables further individualization of the treatment duration. Non-cirrhotic patients with HCV-1 infection, a baseline viremia < 600,000 U/ml and a rapid virologic response (< 50 U/ml at week 4) can achieve a sustained virologic response rate of almost 90% with only 24 weeks of combination therapy. HCV-2 and HCV-3 infected patients with low baseline viremia can be treated for less than 24 weeks without compromising sustained virologic response rates. A longer treatment duration of up to 72 weeks appears reasonable for HCV-1 infected patients with serum HCV RNA levels of 50-6,000 U/ml at week 12 of therapy.

Individualization of antiviral treatment regimens for chronic hepatitis C

The treatment of patients with chronic hepatitis C has rapidly evolved in the past 10 years. The introduction of ribavirin and, more recently, its combination with pegylated interferon represent two landmark changes in improving the treatment efficacy. Overall, sustained virological response at present can be expected in 43-46% of patients infected with genotype 1 and 75-80% in genotype 2 or 3 infection. In addition, factors associated with a lower or greater chance of response to treatment have now been identified, thus providing a basis for modifying current therapy according to the needs of different patient groups. Accumulating evidence demonstrates that individualized treatment regimens, according to the timing of treatment-induced viral clearance, provide a safe and cost-effective approach, as well as an improvement in treatment efficacy.

Comparison of conventional PCR with real-time PCR and branched DNA-based assays for hepatitis C virus RNA quantification and clinical significance for genotypes 1 to 5

The key parameter for diagnosis and management of hepatitis C virus (HCV) infection is HCV RNA. Standardization of HCV RNA assays to IU is mainly based on genotype 1 panels. Little is known about the variability of commercially available HCV RNA assays for quantification of different genotypes. Two real-time reverse transcription (RT)-PCR assays (COBAS TaqMan HCV Test for use with the High-Pure System [HPS/CTM] and COBAS Ampliprep/COBAS TaqMan HCV Test [CAP/CTM]), one standard RT-PCR assay (COBAS Amplicor HCV Monitor 2.0 [CAM]), and one signal amplification assay (Versant Quantitative 3.0 [branched DNA [bDNA]]) were compared for quantification of genotypes 1 to 5 (n = 108). Using CAM as a reference assay for genotype 1-infected patients, the mean interassay differences compared with CAP/CTM, HPS/CTM, and bDNA were 0.16, -0.13, and -0.48 log(10) IU/ml HCV RNA, respectively. Comparison of CAM with CAP/CTM, HPS/CTM, and bDNA for the remaining genotypes showed the following results, respectively: 2a/c, -0.24, -0.78, and -0.49; 2b, -0.21, -0.18, and -0.64; 3a, 0.13, -1.04, and -0.55; 4, -0.52, -1.51, and -0.05; and 5, -0.28, -1.00, and -0.24 log IU/ml HCV RNA. A correct decision for treatment discontinuation in genotype 1 patients at week 12 was possible only when the same assay was used at baseline and week 12. Comparison of CAM with the CAP/CTM assay showed equal quantifications of genotype 1, 2, 3, and 5 samples, while genotype 4 samples were slightly underestimated. For the HPS/CTM assay, a significant underestimation of the HCV RNA concentrations of genotypes 2a/c, 3, 4, and 5 was observed. For the bDNA assay, a constant lower quantification of genotypes 1 to 3 was detected.

Interferon alpha plus ribavirin combination treatment of Japanese chronic hepatitis C patients with HCV genotype 2: A project of the Kyushu University Liver Disease Study Group

AIM: To determine the efficacy of an interferon alpha and ribavirin combination treatment for Japanese patients infected with hepatitis C virus (HCV) of genotype 2, a multi-center study was retrospectively analyzed.

METHODS: In total, 173 patients with HCV genotype 2 started to receive interferon-alpha subcutaneously thrice a week and 600–800 mg of ribavirin daily for 24 wk.

RESULTS: The overall sustained virological response (SVR), defined as undetectable HCV RNA in serum, 24 wk after the end of treatment, was remarkably high by 84.4 %, (146/173) by an intention-to-treat analysis. A significant difference in SVR was found between patients with and without the discontinuation of ribavirin (46.9% vs 92.9 %), but no difference was found between those with and without a dose reduction of ribavirin. A significant difference in SVR was also found between patients with less than 16 wk and patients with 16 or more weeks of ribavirin treatment (34.8 % vs 92.0 %).

CONCLUSION: The 24-wk interferon and ribavirin treatment is highly effective for Japanese patients with HCV genotype 2. The significant predictor of SVR is continuation of the ribavirin treatment for up to 16 weeks.

Development and validation of two models for early prediction of response to therapy in genotype 1 chronic hepatitis C

Early prediction of response to therapy in genotype 1 chronic hepatitis C is difficult. Two predictive models, a pretreatment scoring model (PreT-SM) and a fourth week of therapy scoring model (4w-SM) were constructed in a cohort of 104 patients from a single center (estimation cohort) and validated in a cohort of 141 patients from four independent centers (validation cohort). Individual scores were calculated using variables independently associated with sustained virological response (SVR). Baseline viral load, aspartate aminotransferase/alanine aminotransferase ratio, serum cholesterol, and a numerical score for noninvasive estimation of liver fibrosis were included in the PreT-SM; HCV RNA clearance and PreT-SM scores were included in the 4w-SM. Receiver operating characteristic analysis revealed the area under the curve in the estimation cohort and in the validation cohort to be, respectively, 0.856 and 0.847 for the PreT-SM and 0.908 and 0.907 for the 4w-SM. Low scores were associated with SVR, high scores with non-SVR. The best cutoff scores from the PreT-SM (7 and 9.70) identified, respectively, 36% of patients with SVR and 41% of those with non-SVR from the validation cohort, with high accuracy (> or =90% positive predictive value [PPV] and specificity). Similarly, cutoff scores of 3.20 and 5.60 from the 4w-SM identified, respectively, 71% of patients with SVR and 53% of those with non-SVR from the same cohort with high accuracy (PPV and specificity >92%). In conclusion, these models predicted response to therapy before or after 4 weeks of treatment in approximately 60% of genotype 1 patients and may be valuable for the management of this condition.

Hepatitis C virus serologic and virologic tests and clinical diagnosis of HCV-related liver disease

The use of serological and virological tests has become essential in the management of hepatitis C virus (HCV) infection in order to diagnose infection, guide treatment decisions and assess the virological response to antiviral therapy. Virological tools include serological assays for anti-HCV antibody detection and serological determination of the HCV genotype, and molecular assays that detect and quantify HCV RNA and determine the HCV genotype. Anti-HCV antibody testing and HCV RNA testing are used to diagnose acute and chronic hepatitis C. Only patients with detectable HCV RNA should be considered for pegylated interferon alfa and ribavirin therapy and the HCV genotype should be systematically determined before treatment, as it determines the indication, the duration of treatment, the dose of ribavirin and the virological monitoring procedure. HCV RNA monitoring during therapy is used to tailor treatment duration in HCV genotype 1 infection, and molecular assays are used to assess the end-of-treatment and, most importantly the sustained virological response, i.e. the endpoint of therapy.

Future trends in hepatitis C therapy

The development of new treatment strategies for the therapy of hepatitis C is an unmet need. There has already been an enormous improvement in the therapy of chronic hepatitis C since the early 1990s, but the sustained virologic response rates are still unsatisfactory for certain patient groups. Novel therapeutic strategies, especially for the difficult-to-treat patients, are currently being tested. This review discusses the latest achievements in the treatment of chronic heptatis C.

Chronic hepatitis C virus management: 2000-2005 update

OBJECTIVE

To review recent advances that have significantly changed the management of chronic hepatitis C virus (HCV) infection.

DATA SOURCES

A MEDLINE search (2000-July 2005) was conducted using key words such as hepatitis C, interferon, pegylated interferon, and therapy.

STUDY SELECTION AND DATA EXTRACTION

All articles pertaining to treatment of chronic HCV infection were identified. Studies evaluating HCV treatment in treatment-naive patients were considered for this review.

DATA SYNTHESIS

Over the past several years, response to treatment for chronic HCV infection has significantly improved with the use of pegylated interferon and ribavirin therapy. Treatment response is influenced by HCV genotype and viral load, as well as patient-related factors, including adherence.

CONCLUSIONS

Treatment of chronic HCV infection has improved, with overall response rates of approximately 55%. Identification and management of common adverse effects is important in maximizing adherence and response to therapy. Studies are needed to further delineate the optimum treatment of chronic HCV infection in specific patient populations.

Use of virologic assays in the diagnosis and management of hepatitis C virus infection

This article discusses the use of virologic assays in the diagnosis and management of hepatitis C virus (HCV) infection. The use of virologic tests has become essential in the management of HCV infection to diagnose HCV infection, guide treatment decisions, and assess the virologic response to antiviral therapy. The continuing development of test systems accompanied by new antiviral drugs and novel therapeutic approaches should lead to an optimization of the treatment of HCV infection.

Impaired Response to Interferon-α2B plus Ribavirin in Cirrhotic Patients with Genotype 3A Hepatitis C Virus Infection

Patients with chronic infection with the 3a genotype of hepatitis C virus (HCV) are considered as ‘easy-to-treat’ with interferon/ribavirin (IFN/RBV), independent of liver disease severity. However, patients with extensive fibrosis or cirrhosis were under-represented in all the registration Phase III trials performed so far. To assess the influence of liver fibrosis on the outcome of anti-HCV therapy, all patients with genotype 3a hepatitis C who were naive to IFN-based therapies, and received RBV combined with standard IFN or pegylated IFN-α2b (peg-IFN-α2b) as standard of care for their disease, were investigated at our centre. A sustained virological response (SVR) was achieved in 68 of 91 patients (75%) independent of IFN type, pretreatment viraemia, clearance of HCV RNA at week 4 and relevant co-morbidities. A SVR was less common in cirrhotics (6 of 17) than in non-cirrhotics (62 of 74; 35% vs 84%; P<0.0005). Compared to non-cirrhotics, the age and sex adjusted odds ratio (OR) of treatment failure for cirrhotics was 10.1 (95% confidence interval: 2.4–41.7). By multivariate analysis, cirrhosis was the only predictor of non-SVR. In conclusion, cirrhosis is an independent predictor of IFN/RBV treatment failure in patients chronically infected with HCV 3a and is associated with an increased risk of post-treatment hepatitis relapse. Evaluation of liver fibrosis is important in the management of patients with genotype 3a hepatitis C, since it helps to predict response to IFN/RBV therapy.

Peginterferon alfa-2b and ribavirin for 12 vs. 24 weeks in HCV genotype 2 or 3

BACKGROUND

We hypothesized that in patients with hepatitis C virus (HCV) genotype 2 or 3 in whom HCV RNA is not detectable after 4 weeks of therapy, 12 weeks of treatment is as effective as 24 weeks.

METHODS

A total of 283 patients were randomly assigned to a standard 24-week regimen of peginterferon alfa-2b at a dose of 1.0 mug per kilogram weekly plus ribavirin at a dose of 1000 mg or 1200 mg daily, on the basis of body weight. Of these, 70 patients were assigned to the 24-week regimen (standard-duration group) and 213 patients to a variable regimen (variable-duration group) of 12 or 24 weeks, depending on whether tests for HCV RNA were negative or positive at week 4. The primary end point was HCV that was not detectable by polymerase-chain-reaction (PCR) assay 24 weeks after the completion of therapy.

RESULTS

In the standard-duration group, 45 (64 percent) patients had HCV that was not detectable by PCR assay at week 4, as compared with 133 (62 percent) in the variable-duration group (difference [the rate in the standard-duration group minus that in the variable-duration group], 2 percent; 95 percent confidence interval, -11 to 15 percent). Fifty-three patients (76 percent) in the standard-duration group and 164 patients (77 percent) in the variable-duration group had a sustained virologic response (difference, -1 percent; 95 percent confidence interval, -13 to 10 percent). Fewer patients in the variable-duration group receiving the 12-week regimen had adverse events and withdrew than in the group receiving the 24-week regimen (P=0.045). The rate of relapse (defined as HCV not detectable at the end of treatment but detectable at the end of follow-up) was 3.6 percent in the standard-duration group and 8.9 percent in the variable-duration group (P=0.16). Overall, the rate of sustained virologic response was 80 percent among patients with HCV genotype 2 and 66 percent among those with genotype 3 (P<0.001).

CONCLUSIONS

A shorter course of therapy over 12 weeks with peginterferon alfa-2b and ribavirin is as effective as a 24-week course for patients with HCV genotype 2 or 3 who have a response to treatment at 4 weeks.