Ribavirin and interferon-alpha combination therapy vs interferon-alpha alone in the retreatment of chronic hepatitis C: a randomized clinical trial

A statistical method for removing unbalanced trials with multiple covariates in meta-analysis

In meta-analysis literature, there are several checklists describing the procedures necessary to evaluate studies from a qualitative point of view, whereas preliminary quantitative and statistical investigations on the "combinability" of trials have been neglected. Covariate balance is an important prerequisite to conduct meta-analysis. We propose a method to identify unbalanced trials with respect to a set of covariates, in presence of covariate imbalance, namely when the randomized controlled trials generate a meta-sample that cannot satisfy the requisite of randomization/combinability in meta-analysis. The method is able to identify the unbalanced trials, through four stages aimed at achieving combinability. The studies responsible for the imbalance are identified, and then they can be eliminated. The proposed procedure is simple and relies on the combined Anderson-Darling test applied to the Empirical Cumulative Distribution Functions of both experimental and control meta-arms. To illustrate the method in practice, two datasets from well-known meta-analyses in the literature are used.

Mono- and combinational drug therapies for global viral pandemic preparedness

Broadly effective antiviral therapies must be developed to be ready for clinical trials, which should begin soon after the emergence of new life-threatening viruses. Here, we pave the way towards this goal by reviewing conserved druggable virus-host interactions, mechanisms of action, immunomodulatory properties of available broad-spectrum antivirals (BSAs), routes of BSA delivery, and interactions of BSAs with other antivirals. Based on the review, we concluded that the range of indications of BSAs can be expanded, and new pan- and cross-viral mono- and combinational therapies can be developed. We have also developed a new scoring algorithm that can help identify the most promising few of the thousands of potential BSAs and BSA-containing drug cocktails (BCCs) to prioritize their development during the critical period between the identification of a new virus and the development of virus-specific vaccines, drugs, and therapeutic antibodies.

Cancer immunotherapy: A comprehensive appraisal of its modes of application

Conventional cancer treatments such as chemotherapy and radiation therapy have reached their therapeutic potential, leaving a gap for developing more effective cancer therapeutics. Cancer cells evade the immune system using various mechanisms of immune tolerance, underlying the potential impact of immunotherapy in the treatment of cancer. Immunotherapy includes several approaches such as activating the immune system in a cytokine-dependent manner, manipulating the feedback mechanisms involved in the immune response, enhancing the immune response via lymphocyte expansion and using cancer vaccines to elicit long-lasting, robust responses. These techniques can be used as monotherapies or combination therapies. The present review describes the immune-based mechanisms involved in tumor cell proliferation and maintenance and the rationale underlying various treatment methods. In addition, the present review provides insight into the potential of immunotherapy used alone or in combination with various types of therapeutics.

Two cases of interferon-alpha-induced sarcoidosis Koebnerized along venous drainage lines: new pathogenic insights and review of the literature of interferon-induced sarcoidosis

Sarcoidosis is a systemic granulomatous disorder of unknown origin commonly affecting the lung, the lymphoid system and the skin. We report here two cases of cutaneous sarcoidosis in two former intravenous drug users following interferon (IFN)-α and ribavirin therapy for chronic hepatitis C. Both patients developed skin sarcoidosis along venous drainage lines of both forearms, coinciding with the areas of prior drug injections. The unique distribution of the skin lesions suggests that tissue damage induced by repeated percutaneous drug injections represents a trigger for the local skin manifestation of sarcoidosis. Interestingly, skin damage was recently found to induce the local expression IFN-α, a well-known trigger of sarcoidosis in predisposed individuals. Here we review the literature on sarcoidosis elicited in the context of IFN-α therapy and propose a new link between the endogenous expression of IFN-α and the induction of disease manifestations in injured skin.

Interferon for interferon nonresponding and relapsing patients with chronic hepatitis C

BACKGROUND

The widely-accepted treatment outcome for chronic hepatitis C is the sustained viral response (that is, no measurable viral RNA in blood six months after treatment). However, this surrogate outcome (as well as the previously employed biochemical and histologic ones) has never been validated. This situation exists because there are very few randomized clinical trials that have used clinical events (mortality or manifestations of decompensated cirrhosis) as outcomes, because those clinical events only occur after many years of infection. Patients in whom initial therapy fails to produce sustained viral responses do become potential candidates for retreatment; some of these individuals are not candidates for ribavirin or protease inhibitors and consideration could be given to retreatment with interferon alone.

OBJECTIVES

To assess the benefits and harms of interferon monotherapy retreatment in chronic hepatitis C patients and to validate the currently employed surrogate outcomes in this group of patients.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until 16 August 2012.

SELECTION CRITERIA

Randomized trials comparing interferon versus placebo or no treatment in chronic hepatitis C nonresponders and relapsers to previous interferon.

DATA COLLECTION AND ANALYSIS

The primary outcomes were mortality (all-cause and hepatic), quality of life, and adverse events. Secondary outcomes were liver-related morbidity, sustained viral responses, biochemical responses, histologic improvements, and costs. We used both fixed-effect and random-effects model meta-analyses, reporting only the former if no difference existed.

MAIN RESULTS

Seven trials were identified. Two of them were at low risk of bias (the HALT-C and EPIC3 trials) and included 1676 patients. Both of these trials addressed the role of long-term low-dose pegylated interferon therapy in patients with severe fibrosis (demonstrated on liver biopsy) and were designed to assess the clinical outcomes. The remaining five trials included 300 patients and were at high risk of bias. Based on all trials reporting the outcomes, no significant difference was observed in either all-cause mortality (78/843 (9.3%) versus 62/867 (7.2%); risk ratio (RR) 1.30, 95% confidence interval (CI) 0.95 to 1.79; 3 trials) or hepatic mortality (41/532 (7.7%) versus 40/552 (7.2%); RR 1.07, 95% CI 0.70 to 1.63; 2 trials); however, when only the two trials at low risk of bias were combined, all-cause mortality was significantly higher in the recipients of the pegylated interferon (78/828 (9.4%) versus 57/848 (6.7%); RR 1.41, 95% CI 1.02 to 1.96) although trial sequential analysis could not exclude the possibility of random error. There was less variceal bleeding in the recipients of the interferon (4/843 (0.5%) versus 18/867 (2.1%); RR 0.24, 95% CI 0.09 to 0.67; 3 trials), although again trial sequential analysis could not exclude the presence of a type I error and the effect could not be confirmed in a random-effects model meta-analysis. No significant differences were seen with regard to the development of ascites, encephalopathy, hepatocellular carcinoma, or the need for liver transplantation. One trial reported quality of life data; the pain score was significantly worse in the recipients of the pegylated interferon. Adverse effects tended to be more common in the interferon recipients; the ones that were significantly more common included hematologic complications, infections, flu-like symptoms, and rash. The recipients of interferon had significantly more sustained viral responses (20/557 (3.6%) versus 1/579 (0.2%); RR 15.38, 95% CI 2.93 to 80.71; 4 trials) and a type I error was excluded by trial sequential analysis. The METAVIR activity score also improved (36/55 (65%) versus 20/46 (43.5%); RR 1.49, 95% CI 1.02 to 2.18; 2 trials). No significant differences were seen with regard to histologic fibrosis assessments.

AUTHORS' CONCLUSIONS

The clinical data were limited to patients with histologic evidence of severe fibrosis who were retreated with pegylated interferon. In this scenario, retreatment with interferon did not appear to provide significant clinical benefit and, when only the trials at low risk of bias were considered, retreatment for several years may even have increased all-cause mortality. Such treatment also produced adverse events. On the other hand, the treatment did result in improvement in some surrogate outcomes, namely sustained viral responses and histologic evidence of inflammation. Interferon monotherapy retreatment cannot be recommended for these patients. No clinical data are available for patients with less severe fibrosis. The sustained viral response cannot be used as a surrogate marker for hepatitis C treatment in this clinical setting with low sustained viral response rates and needs to be validated in others in which higher sustained viral response rates are reported.

Advantage of IFN-beta/alpha2b same-day administration for ribavirin-intolerant patients with chronic hepatitis C

AIM

Although interferon (IFN)/ribavirin is the mainstream combination treatment for chronic hepatitis C in patients with a high viral load, ribavirin is problematic for women of childbearing age and patients with anemia. Therefore we needed to establish a new regimen without ribavirin.

METHODS

We devised a new regimen (same-day beta/alpha2b) to administer IFN-beta and alpha2b on the same-day, and compared it with IFN-alpha2b alone and IFN-alpha2b plus ribavirin. The cases were 36 patients (26.1%) in whom ribavirin could not be used (young women, anemia, etc.) among 138 patients who underwent IFN treatment after ribavirin release.

RESULTS

The percentages of patients withdrawing due to side-effects were 6.8%, 18.8% and 17.0% in the treatment with same-day beta/alpha2b, IFN-alpha2b alone and IFN-alpha2b plus ribavirin groups, respectively. In genotype 1b, the sustained viral response (SVR) was 28.6% (4/14), 13.6% (3/22) and 25.0% (8/32) with a high viral load, and 91.7% (11/12), 27.3% (3/11) and 57.1% (4/7) with a low viral load for the respective groups. According to a study on viral half-life during the early phase of IFN therapy, there was no difference among the regimens of same-day IFN-beta/alpha2b, beta alone, alpha2b alone and twice-daily treatment with IFN-beta. Same-day beta/alpha2b treatment showed a significantly higher SVR rate in moving type patients with a genotype 1b/high viral load.

CONCLUSIONS

Same-day beta/alpha2b treatment resulted in few cases where therapy was discontinued and showed a high SVR rate. This regimen is especially appropriate in cases where ribavirin has been deemed unsuitable.

Ribavirin plus interferon versus interferon for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. Standard therapy is ribavirin plus pegylated interferon to achieve undetectable level of virus in the blood, but the effect on clinical outcomes is controversial.

OBJECTIVES

To assess the beneficial and harmful effects of ribavirin and interferon combination therapy versus interferon monotherapy for chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, approaching authors of trials, and pharmaceutical companies until March 2009.

SELECTION CRITERIA

We included randomised trials, irrespective of blinding, language, or publication status, comparing ribavirin plus interferon versus interferon for treatment of chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were serum sustained loss of hepatitis C virus, liver-related morbidity plus all-cause mortality, and adverse events. We performed subgroup analyses of patients who were naive, relapsers, or non-responders to previous antiviral treatment. All outcomes were analysed with the random-effects model. We used Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of morbidity plus mortality. The remaining outcomes were presented as relative risks (RR). We used trial sequential analyses to examine the robustness of our findings.

MAIN RESULTS

We included 83 randomised trials with 12,707 patients. Most trials had unclear or high risk of bias. We did not find any significant influence of bias on our results but cannot exclude outcome measure reporting bias as many trials did not report on the primary outcomes of this review. Compared with interferon, ribavirin plus interferon had a significant beneficial effect on sustained virological response in subgroups of naive patients (RR 0.72, 95% confidence interval (CI) 0.68 to 0.75), relapsers (RR 0.62, 95% CI 0.54 to 0.70), non-responders (RR 0.89, 95% CI 0.84 to 0.93), and in all patients (RR 0.75, 95% CI 0.71 to 0.79). Combination therapy significantly reduced morbidity plus mortality in all patients (Peto OR, 0.43, 95% CI 0.23 to 0.79), but not in naive, relapsers, or non-responders individually. Combination therapy significantly increased the risk of haematological, dermatological, gastrointestinal, infectious, and miscellaneous (cough, dyspnoea, fatigue) adverse reactions. Accordingly, combination therapy significantly increased the risk of treatment discontinuation and dose reductions. Trial sequential analyses confirmed our findings regarding virological effects, but not regarding liver-related morbidity and all-cause mortality.

AUTHORS' CONCLUSIONS

Compared with interferon alone, ribavirin plus interferon is more effective in clearing hepatitis C virus from the blood. Combination therapy may reduce liver-related morbidity and all-cause mortality, but we need more evidence. The number needed to treat to obtain a beneficial effect is considerable considering the increased risk of several severe adverse reactions and costs.

Ribavirin monotherapy for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. A high proportion of patients never experience symptoms. Peginterferon plus ribavirin is the recommended treatment for chronic hepatitis C. However, ribavirin monotherapy may be considered for some patients.

OBJECTIVES

To assess the beneficial and harmful effects of ribavirin monotherapy for patients with chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies until March 2009.

SELECTION CRITERIA

We included all randomised trials irrespective of blinding, language, or publication status comparing ribavirin versus no intervention, placebo, or interferon for chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were serum sustained virological response (loss of hepatitis C virus RNA at least six months after treatment), liver-related morbidity plus all-cause mortality, and adverse events. Secondary outcome measures were end of treatment virological response, biochemical response (transaminase activity), and histological response. Randomisation methods, blinding, data handling, and funding were extracted as measures of bias control. Random-effects and fixed-effect meta-analyses were performed for all outcomes. We only present the results of the fixed-effect model if both models provide the same result regarding statistical significance. We present data as risk difference (RD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 14 randomised trials with 657 patients. The majority of trials had unclear control of bias. Compared with placebo or no intervention, ribavirin had no significant effect on the sustained virological response (RD 0%, 95% CI -2% to 3%, five trials) or end of treatment virological response (RD 0% 95% CI -3% to 3%, ten trials). Ribavirin had no significant effect on liver-related morbidity plus mortality (RD 0%, 95% CI -2% to 3%, 11 trials). Ribavirin significantly increased the risk of adverse reactions, including anaemia. Ribavirin significantly improved end of treatment biochemical and histological response but not the sustained biochemical response. Ribavirin was significantly inferior to interferon regarding virological and biochemical responses (five trials).

AUTHORS' CONCLUSIONS

Ribavirin seems without beneficial effects on serum virological response and liver-related morbidity or mortality, and significantly increased the risk of adverse reactions. Ribavirin monotherapy seems significantly inferior to interferon monotherapy. The total number of included patients is small, and more trials are perhaps needed. The use of ribavirin monotherapy for chronic hepatitis C cannot be recommended outside randomised trials.

WITHDRAWN: Ribavirin with or without alpha interferon for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. Ribavirin plus interferon combination therapy is presently considered the optimal treatment of interferon naive patients with chronic hepatitis C, but its role in relapsers and non-responders to previous interferon therapy is not established.

OBJECTIVES

To assess the efficacy and safety of ribavirin alone or in combination with alpha interferon in interferon naive patients, relapsers, and non-responders with chronic hepatitis C.

SEARCH STRATEGY

Eligible trials were identified through searches on electronic databases: The Cochrane Hepato-Biliary Group Controlled Trials Register (August 2001), The Cochrane Controlled Trials Register on The Cochrane Library Issue 3, 2001, MEDLINE (1966 - August 2001), and EMBASE (1985 - August 2001). Manual searches of bibliographies and journals were done as well as authors of trials and pharmaceutical companies producing ribavirin or interferon were contacted.

SELECTION CRITERIA

We included all randomised trials comparing ribavirin with or without alpha interferon versus no intervention, placebo, or alpha interferon for chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the 'sustained' (six months after treatment) virological response, and morbidity plus mortality. The secondary outcome measures were the 'end of treatment' and 'sustained' biochemical response, the 'end of treatment' virologic response, histology, quality of life, and adverse events.

MAIN RESULTS

We included eight trials in which 271 patients were randomised to ribavirin versus placebo or no intervention and 48 trials in which 6585 patients were randomised to interferon with or without ribavirin. Compared with placebo or no intervention, ribavirin monotherapy had no significant effect on the virological response or histology and only a transient effect on the biochemical response. Compared with interferon, combination therapy reduced the risk of not having a sustained virological response by 26% in naive patients (relative risk (RR) 0.74; 95% confidence interval (CI) 0.70-0.78), 33% in relapsers (RR 0.67; 95% CI 0.57-0.78), and 11% in non-responders (RR 0.89; 95% CI 0.83-0.96). There was no significant effect on morbidity plus mortality (Peto odds ratio 0.45; 95% CI 0.19-1.06). Irrespective of previous therapy, combination therapy significantly reduced the risk of not having a sustained biochemical response (RR 0.76; 95% CI 0.59-0.84) or improved histology (RR 0.67; 95% CI 0.56-0.81). Combination therapy also significantly increased the risk of treatment discontinuation (RR 1.28; 95% CI 1.07-1.52) and several types of adverse events.

AUTHORS' CONCLUSIONS

Combination therapy increased the number of naive patients, relapsers, and non-responders with a sustained virological, biochemical, or histological response, but also the occurrence of adverse events.

A randomized trial of pegylated interferon alpha-2b plus ribavirin in the retreatment of chronic hepatitis C

OBJECTIVES

The efficacy of combination therapy with pegylated interferon (PEG IFN) alpha plus ribavirin (RBV) in the retreatment of chronic hepatitis C (CHC) in patients who previously failed combination standard IFN plus RBV or IFN monotherapy has not been well established.

METHODS

Three hundred and twenty-one CHC patients including virologic nonresponders to combination IFN plus RBV (n = 219) or IFN monotherapy (n = 47), and relapsers to combination therapy (n = 55) were randomized to receive PEG IFN alpha-2b 1.5 microg/kg per wk plus RBV 800 mg per day (Regimen A, n = 160) or PEG IFN alpha-2b 1.0 microg/kg per wk plus RBV 1,000-1,200 mg per day (Regimen B, n = 161) for 48 wks.

RESULTS

Sustained virologic response (SVR) occurred in 16% of the overall study population (Regimen A vs B, 18%vs 13%, p= 0.21), in 8% of the combination therapy nonresponders (10%vs 6%, p= 0.35), in 21% of the IFN monotherapy nonresponders (16%vs 27%, p= 0.35), and in 42% of the combination therapy relapsers (50%vs 32%, p= 0.18). In nonresponders to prior combination therapy, HCV ribonucleic acid levels <100,000 copies/mL at the end of the prior treatment course were associated with an increased SVR compared with levels >or=100,000 copies/mL (21%vs 5%, p= 0.002). In the overall study population, genotype 1 patients had lower SVR rates than others (14%vs 33%, p= 0.01), and African Americans had lower SVR than Caucasians (4%vs 18%, p= 0.01).

CONCLUSION

Combination therapy with PEG IFN alpha-2b plus RBV is more effective in patients who relapsed after combination standard IFN plus RBV than in nonresponders to either combination therapy or IFN monotherapy. There was no significant effect of dosing regimen.

Ribavirin monotherapy for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades. Ribavirin monotherapy may represent a treatment for some patients.

OBJECTIVES

To assess the beneficial and harmful effect of ribavirin monotherapy for patients with chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies until May 2005.

SELECTION CRITERIA

We included all randomised trials irrespective of blinding, language, or publication status comparing ribavirin versus no intervention, placebo, or interferon for chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the six months sustained loss of hepatitis C virus RNA in blood after end of treatment and liver-related morbidity plus all-cause mortality. Secondary outcome measures were end of treatment virological response, biochemical response, histological response, and adverse events. Random- and fixed-effects meta-analyses with 95% confidence intervals (CI) were performed for all outcomes. We used Peto odds ratios (OR) for analysis of morbidity plus mortality and relative risks (RR) for the remaining outcomes.

MAIN RESULTS

We identified 13 randomised trials including 594 patients with chronic hepatitis C. Most trials had low methodological quality. Compared with placebo/no intervention, ribavirin had no significant effect on sustained (RR 1.01, 95% CI 0.96 to 1.07, five trials) or end of treatment virological response (RR 1.00, 95% CI 0.94 to 1.07, ten trials). Ribavirin had no significant effect on liver-related morbidity plus mortality (Peto OR 1.96, 95% CI 0.20 to 19.0, eleven trials). Ribavirin significantly improved end of treatment biochemical and histological response but not sustained biochemical response. Further, ribavirin significantly increased the risk of anaemia. Ribavirin was significantly inferior to interferon regarding virological and biochemical response (four trials).

AUTHORS' CONCLUSIONS

We found that ribavirin versus placebo/no intervention had no significant beneficial effect on virological response and liver morbidity, but may improve biochemical and histological response transiently. Ribavirin increased the risk of anaemia. Therefore, we cannot recommend ribavirin monotherapy for patients with chronic hepatitis C outside randomised trials.

Ribavirin plus interferon versus interferon for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades and most patients are diagnosed based on the presence of hepatitis C virus ribonucleic acid and elevated transaminases.

OBJECTIVES

To assess the beneficial and harmful effects of ribavirin and interferon combination therapy versus interferon monotherapy for chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, approaching authors of trials and pharmaceutical companies, until May 2004.

SELECTION CRITERIA

We included randomised trials, irrespective of blinding, language, or publication status, comparing ribavirin plus interferon versus interferon alone for treatment of chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the sustained loss of hepatitis C virus and liver-related morbidity plus all-cause mortality. We separately analysed patients who were naive, relapsers, or non-responders to previous antiviral treatment. Random-effects and fixed-effect model meta-analyses were performed for all outcomes. We used Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of morbidity plus mortality. The remaining outcomes were presented as relative risks (RR).

MAIN RESULTS

We included 72 randomised trials with 9991 patients. Most trials had low methodological quality but we did not find any significant influence of quality on our results. Compared with interferon, combination therapy had a significant beneficial effect on sustained virological response (RR 0.73, 95% CI 0.71 to 0.75) and in subgroups of naive patients (RR 0.72, 95% CI 0.68 to 0.76), relapsers (RR 0.63, 95% CI 0.54 to 0.73), and non-responders (RR 0.89, 95% CI 0.84 to 0.94) individually. Combination therapy significantly reduced morbidity plus mortality (Peto OR 0.46, 95% CI 0.22 to 0.96), but not in naive, relapsers, or non-responders individually. Combination therapy also had a significant beneficial effect on the histological response. Combination therapy significantly increased the risk of anaemia (RR 10.48, 95% CI 5.34 to 20.55), which occurred in 22% of patients on combination therapy. Combination therapy also significantly increased the risk of dermatological, gastrointestinal, infectious, and miscellaneous (cough, dyspnea, fatigue) adverse events. Accordingly, combination therapy significantly increased the risk of treatment discontinuation (RR 1.19, 95% CI 1.01 to 1.39).

AUTHORS' CONCLUSIONS

Compared with interferon alone, ribavirin plus interferon is more effective in clearing hepatitis C virus and improving liver histology. This may lead to reduced morbidity and mortality. However, combination therapy significantly increased the risk of several adverse events.

Dynamic decision analysis to determine optimal treatment duration in chronic hepatitis C

BACKGROUND

Current guidelines for stopping treatment of chronic hepatitis C are based on hepatitis C ribonucleic acid measurements at 12 and 24 weeks.

AIM

To explore an alternative approach for making individualized recommendations about treatment duration, based on simple alanine aminotransferase tests and on cost-per-cure.

METHODS

We analysed individual patient data from 13 randomized, controlled trials with interferon alone or combined with ribavirin. Using multiple logistic regression, we built a model that estimated the probability of sustained virological response for treatment durations of 24 and 48 weeks. Decisions to prolong treatment were based on an increase in probability of sustained virological response. If the increase was 10%, the cost-per-cure became decisive with a limit of 50,000.

RESULTS

Noncirrhotics with genotype 2 or 3 did not benefit when treatment was continued beyond 24 weeks. Sustained virological response rates in cirrhotic patients increased by 14-47% if treatment was continued up to 48 weeks. In noncirrhotic genotype 1 or 4 patients who had elevated alanine aminotransferase levels at week 4, the probability of sustained virological response increased by <10% if treatment was continued up to 48 weeks; the cost-per-cure for these patients would exceed 50,000.

CONCLUSION

The dynamics of alanine aminotransferase levels and cost-per-cure provides a useful alternative to determine the duration of therapy in chronic hepatitis C.

A randomized trial of prolonged high dose of interferon plus ribavirin for hepatitis C patients nonresponders to interferon alone

Retreatment of chronic hepatitis C patients nonresponders to interferon (IFN) alone with the standard dose of IFN [3 million units (MU) thrice weekly (TIW)] plus ribavirin for 24 weeks has yielded low sustained virological response (SVR), averaging 8%. The aim of the present, open-labelled, randomized study was to evaluate the efficacy of IFN induction therapy followed by prolonged high dose of IFN plus ribavirin in nonresponders. One hundred and fifty-one patients were randomized to receive 5 MU daily of IFN alfa-2b (group 1, n = 73) or 5 MU TIW of IFN alfa 2b (group 2, n = 78) for 4 weeks followed by IFN (5 MU TIW) plus ribavirin (1000/1200 mg/daily) for 48 weeks in both groups. In an intention-to-treat analysis, the sustained virological response (SVR) at 24-week follow-up was 33 and 23% for group 1 and 2, respectively (P = 0.17). The overall SVR was 52 and 18% in patients with genotype 2/3 and 1/4, respectively. Among genotype 1/4 patients the SVR was 29 and 11% for age younger or older than 40 years. Compared with genotype 2/3 patients, the risk (95% confidence interval) of nonresponse to retreatment was 3.0-fold (1.17-8.0) in younger genotype 1/4 patients and 8.4-fold (3.0-23.29) in older genotype 1/4 patients. In conclusion these results suggest that retreatment with a reinforced regimen should be focused in nonresponder genotype 2/3 patients and younger genotype 1/4 patients, who are most likely to benefit. Induction therapy does not improve SVR.

Effects of ribavirin combined with interferon-alpha 2b on viral kinetics during first 12 weeks of treatment in patients with hepatitis C virus genotype 1 and high baseline viral loads

This study aimed to find how ribavirin increases viral disappearance in patients with hepatitis C virus (HCV) of genotype 1 and high baseline viral loads (>5.0 x 10(5) copies/mL) when given with interferon (IFN). Using the real-time quantitative polymerase chain reaction, we measured serum HCV in 20 patients during the first 12 weeks of therapy with IFN-alpha 2b and ribavirin. Controls were 10 similar patients given IFN-alpha 2b alone. IFN-alpha 2b was given at 6 MU daily for 2 weeks, and then three times weekly. Ribavirin was given at 600 or 800 mg daily. Serum HCV RNA decreased rapidly in the first phase, during the first 24 h of therapy (day 0), and more slowly in the early second phase (days 1-14). The median decrease was by 1.41 and 0.078 log 10/day in these two phases in the combination therapy group, and 0.90 and 0.081 log 10/day in the monotherapy group. The difference between groups in the first phase was not significant (P = 0.24), nor was that in the next phase (P = 0.68). Later in the second phase, between days 14 and 84, the median decrease was larger in the combination therapy group (0.030 log 10/day) than in the monotherapy group (0.015 log 10/day, P = 0.035). In patients with HCV genotype 1 and high viral loads, the effects of ribavirin with IFN-alpha appeared slowly, after the earliest days of treatment. A long-term favourable outcome of combination therapy may be associated with a rapid viral decline in this later phase of therapy.

Retreatment of hepatitis C non-responsive to interferon. A placebo controlled randomized trial of ribavirin monotherapy versus combination therapy with Ribavirin and Interferon in 121 patients in the Benelux [ISRCTN53821378]

BACKGROUND

Evidence based medicine depends on unbiased selection of completed randomized controlled trials. For completeness it is important to publish all trials. This report describes the first large randomised controlled trial where combination therapy was compared to placebo therapy and to ribavirin monotherapy, which has not been published until now.

METHODS

One hundred and twenty one patients with chronic hepatitis C and elevated transaminases who did not respond to previous treatment with standard interferon monotherapy, were included from 16 centers in Belgium, the Netherlands and Luxembourg between 1992 and 1996. Patient poor-response characteristics were: genotype 1 (69%), HCV RNA above 2 x 10(6) copies/ml (55%) and cirrhosis (38%). Patients were randomized to 6 months combination therapy with interferon alpha-2b (3 MU tiw) and ribavirin (1000-1200 mg/day), 6 months ribavirin monotherapy (1000-1200 mg/day) or 6 months ribavirin placebo. The study was double blinded for the ribavirin/placebo component. One patient did not fit the entry criteria, and 3 did not start. All 117 patients who received at least one dose of treatment were included in the intention to treat analysis.

RESULTS

At the end of treatment, HCV RNA was undetectable in 35% of patients on combination therapy and in none of the patients treated with ribavirin monotherapy or placebo. The sustained virological response rate at 6 months after therapy was 15% for patients treated with interferon and ribavirin. During the 6 months treatment period 13% of patients on interferon ribavirin combination therapy, 13% of patients on ribavirin monotherapy and 11% of patients on placebo withdrew due to side effects or noncompliance. At 24 weeks of treatment the mean Hb level was 85% of the baseline value, which means a mean decrease from 9.1 mmol/l to 7.8 mmol/l. The Hb levels at the end of treatment were not significantly different from patients treated with ribavirin monotherapy (p = 0.76). End of treatment WBC was significantly lower in patients treated with combination therapy, compared to ribavirin (p < 0.01) as well as for patients treated with ribavirin monotherapy compared to placebo (p < 0.01).

DISCUSSION

This belated report on the only placebo controlled study of interferon ribavirin combination therapy in non responders to standard doses of interferon monotherapy documents the effectiveness, be it limited, of this approach as well as the dynamics of the effects on blood counts.

A randomized trial to assess the efficacy of interferon alpha in combination with ribavirin in the treatment of interferon alpha nonresponders with chronic hepatitis C: superior efficacy of high daily dosage of interferon alpha in genotype 1

A randomized trial was conducted to assess the efficacy of daily (QD) or thrice weekly (TIW) administration of interferon-alpha (IFN) in high doses in combination with ribavirin (1.0-1.2 g/day) in patients with chronic hepatitis C (CHC) who were nonresponders to previous IFN monotherapy. Interferon was administered as 10 MU IFN (QD or TIW) for 4 weeks, followed by 5 MU IFN (QD or TIW) for 20 weeks, and then by 3 MU IFN (QD or TIW) for 24 weeks. Sustained virological response (SVR) was evaluated in 142 patients who received at least one dose of medication. One-fourth of the patients achieved SVR, 26% of those treated with IFN QD and 25% of those treated with IFN TIW (P = 0.85). For genotype 1 patients, SVR rates were 32.4 and 15.8% for IFN QD and IFN TIW, respectively, whereas for genotype non-1 patients the corresponding SVR rates were 20.6 and 36.4%, respectively (test of homogeneity: P = 0.031). This finding was further confirmed by multivariate logistic regression analysis where a statistically significant interaction (P = 0.012) was found between treatment and HCV genotype indicating that the IFN QD regimen was superior to IFN TIW among genotype 1 patients whereas, among genotype non-1 patients, the two treatments were similar (odds ratio of SVR in IFN QD vs IFN TIW: 3.33 among genotype 1 patients, 95% CI: 1.00-11.14). In conclusion, re-treatment of patients not responding to previous IFN monotherapy with a combination of high daily dose of IFN with ribavirin may be beneficial for genotype 1 infected patients.

Sustained response to combination therapy in patients with chronic hepatitis C who failed to respond to interferon

BACKGROUND/AIMS

The best treatment for chronic hepatitis C patients who do not respond to interferon is still unknown. Reported rates of response to treatment vary as the result of heterogeneous definitions of non-responders and small study size.

METHODS

One hundred nineteen hepatitis C virus (HCV) RNA-positive non-responders to high-dose interferon monotherapy received alpha-interferon, 5 MU tiw plus oral ribavirin, 1000-1200 mg/day for 48 weeks (Group A, n=74) or alpha-interferon, 5 MU daily for 4 weeks, followed by 5 MU tiw plus oral ribavirin, 1000-1200 mg/day for 44 weeks (Group B, n=45) according to the Institution where they were followed. Persistently normal alanine aminotransferase and negative HCV RNA up to 72 weeks from treatment onset defined a sustained response.

RESULTS

Eighteen patients discontinued treatment (13 developed anemia, two mucositis, one granulocytopenia; two were dropouts), none for serious adverse events. There were 24 (20%) sustained responders, with similar final response rates in Groups A and B. Sustained response was more frequent in patients aged </=40 years (36% vs. 13%; P=0.006) and in those with non-1 genotype (44% vs. 14%; P=0.002). Among genotype 1 patients, the younger ones showed higher response rates (32% vs. 7%; P=0.005). Compared with patients harboring non-1 genotypes, the odds ratio of being a non-responder was 1.68 (confidence interval (CI): 0.53-5.37; P=0.381) in younger genotype 1 patients and 9.53 (CI: 2.84-32; P<0.001) in older genotype 1 patients.

CONCLUSIONS

Chronic hepatitis C patients who are non-responders to interferon monotherapy and infected by non-1 genotypes should undergo re-treatment with combination therapy. Treatment should be extended to younger genotype 1 patients who are more susceptible to liver disease worsening because of longer life expectancy and have a higher probability of being long lasting responders than their older counterparts.

Meta-analysis: combination therapy with interferon-alpha 2a/2b and ribavirin for patients with chronic hepatitis C previously non-responsive to interferon

BACKGROUND

The efficacy of interferon-alpha plus ribavirin treatment for patients not responding to interferon monotherapy is not well established.

AIM

To assess the efficacy and safety of combination therapy with interferon-alpha 2a/2b plus ribavirin by performing a meta-analysis of randomized clinical trials.

METHODS

A systematic search of electronic databases for randomized clinical trials of interferon-alpha 2a/2b plus ribavirin was conducted independently by two investigators. Data abstraction was performed. The primary end-point was a sustained virological response. Estimates of the common odds ratio were calculated using a random effects model.

RESULTS

Of the 127 identified studies, 46 were considered for evaluation and 10 were included (1728 patients). The pooled sustained virological response was 12.6% (95% CI, 9.5-16.3%) for combination therapy vs. 2% (95% CI, 0.9-4.0%) for interferon monotherapy, with a common odds ratio of 5.49. Higher doses of interferon, a longer duration of therapy (48 weeks) and genotypes other than 1 and 4 were associated with an improvement in response. More side-effects and discontinuations were observed with combination therapy than with interferon monotherapy.

CONCLUSIONS

Non-responders to interferon may benefit from re-treatment with combination therapy, especially from a 48-week regimen.

Interferon for interferon nonresponding and relapsing patients with chronic hepatitis C

BACKGROUND

Interferon monotherapy leads to sustained virologic clearance in a minority of patients with chronic hepatitis C. Studies have yielded conflicting results regarding retreatment with interferon in nonresponders and relapsers.

OBJECTIVES

To assess the beneficial and harmful effects of retreatment with interferon in chronic hepatitis C nonresponders and relapsers to previous interferon treatment.

SEARCH STRATEGY

Trials were identified through electronic databases, manual searches, authors, and pharmaceutical companies (August 2001).

SELECTION CRITERIA

Randomised trials comparing interferon versus control or different interferon regimens in chronic hepatitis C patients being nonresponders and relapsers to previous interferon were included.

DATA COLLECTION AND ANALYSIS

The primary outcome was failure to achieve a sustained virologic response defined as positive serum hepatitis C virus RNA at least six months following treatment. Secondary outcomes included liver-related morbidity, mortality, biochemical responses, adverse events, and histology.

MAIN RESULTS

Ten randomised trials involving 686 nonresponders and eight trials involving 484 relapsers were included; their methodological quality was poor. In nonresponders, interferon reduced the risk of not achieving an end of treatment biochemical response compared with no treatment (relative risk [RR] 0.77, 95% confidence interval [CI] 0.66 to 0.91); however, virologic responses were not reported. In a post hoc subgroup analysis, doses greater than 3 million units (MU) three times weekly offered no advantage compared with 3 MU three times weekly for biochemical sustained response. Failure to obtain a virologic sustained response was less likely with 48 than 24 weeks of therapy (RR 0.87, 95% CI 0.79 to 0.96). Adverse events did not differ significantly regardless of treatment dose or duration. In relapsers, none of the trials compared interferon with no treatment. In a post hoc analysis, doses greater than 3 MU three times weekly were no more effective in achieving a virologic sustained response than 3 MU three times weekly. Compared with 24 weeks, treatment durations of 48 weeks were less likely to fail to achieve a virologic sustained response (RR 0.69, 95% CI Random 0.51 to 0.95), but associated with more frequent dosage reduction (RR 9.07, 95% CI 1.20 to 68.63). No data regarding clinical outcomes or histology was available in either patient group.

REVIEWER'S CONCLUSIONS

Retreatment with interferon leads to sustained virologic clearance in a minority of chronic hepatitis C patients with nonresponse or relapse following interferon monotherapy. Treatment durations of 48 weeks are superior to 24 weeks, but doses greater than 3 MU three times weekly are no more effective. No data exists regarding the effect on clinical outcomes.

Tolerability of treatments for viral hepatitis

Interferon-alpha is the most widely used antiviral drug in chronic hepatitis B and C. Tolerability is usually good and serious adverse effects are rare. Most of the adverse effects are mild or transient and do not necessitate drug withdrawal. More than 90% of patients who are given interferon-alpha achieve 6 months to 1 year of treatment without serious adverse effects. The serious adverse effects usually occur in predisposed patients with pre-existing organ dysfunction. Nevertheless, careful selection of patients for therapy and observation during therapy are recommended. Nucleoside analogues are promising drugs in the treatment of chronic hepatitis B through inhibition of viral DNA polymerase. Lamivudine has been licensed for use in this indication. Its tolerability is excellent even when used for periods of 1 year or more. The main concern is the relatively high incidence of viral resistance resulting in breakthrough during or relapse after therapy. In the treatment of chronic hepatitis C, ribavirin, in combination with interferon-alpha is currently the reference therapy. The main adverse effect is haemolytic anaemia, which necessitates careful monitoring and adjustment of dosage in many cases. Recently, large trials showed the better efficacy of pegylated interferons as compared with standard interferon. The combination of pegylated interferon with ribavirin is under evaluation.

Management strategies for ribavirin-induced hemolytic anemia in the treatment of hepatitis C: clinical and economic implications

OBJECTIVES

Recently published studies have demonstrated increased efficacy and cost-effectiveness of combination therapy with interferon and alpha-2b/ribavirin compared with interferon-alpha monotherapy in the treatment of chronic hepatitis C (CHC). Combination therapy is associated with a clinically important adverse effect: ribavirin-induced hemolytic anemia (RIHA). The objective of this study was to evaluate the direct health-care costs and management of RIHA during treatment of CHC in a clinical trial setting.

METHODS

A systematic literature review was conducted to synthesize information on the incidence and management of RIHA. Decision-analytic techniques were used to estimate the cost of treating RIHA. Uncertainty was evaluated using sensitivity analyses.

RESULTS

RIHA, defined as a reduction in hemoglobin to less than 100 g/L, occurs in approximately 7% to 9% of patients treated with combination therapy. The standard of care for management of RIHA is reduction or discontinuation of the ribavirin dosage. We estimated the direct cost of treating clinically significant RIHA to be $170 per patient receiving combination therapy per 48-week treatment course (range $68-$692). The results of the one-way sensitivity analyses ranged from $57 to $317. In comparison, the cost of 48 weeks of combination therapy is $16,459.

CONCLUSIONS

The direct cost of treating clinically significant RIHA is 1% ($170/$16,459) of drug treatment costs. Questions remain about the optimal dose of ribavirin and the incidence of RIHA in a real-world population. Despite these uncertainties, this initial evaluation of the direct cost of treating RIHA provides an estimate of the cost and management implications of this clinically important adverse effect.

High-dose prolonged combination therapy in non-responders to interferon monotherapy for chronic hepatitis C

BACKGROUND

Therapy of chronic hepatitis C non- responders to interferon monotherapy with standard doses of interferon plus ribavirin is usually ineffective.

AIM

To evaluate the efficacy and tolerability of high-dose prolonged combination retreatment in non- responder patients.

METHODS

Patients were retreated for 6 months with 6 MU alphaIFN on alternate days and 1000 or 1200 mg/day ribavirin. HCV-RNA negative patients continued therapy for an additional 6 months.

RESULTS

Forty patients (29 males, mean age 49.7 years, 34 genotype 1b, 11 with F3 fibrosis) were treated. At 6 months, 20 (50%) patients were HCV-RNA negative but six of them discontinued therapy because of adverse events. A sustained response was achieved in 28% of patients (11/40). A sustained response was more frequent among patients with genotype non-1b than in those with genotype 1b (67 vs. 21%, P=0.005) and clearance of HCV-RNA in the first 3 months had a high predictive value for sustained response (100% of sustained responders vs. 24% of non-responders, P=0.0001).

CONCLUSIONS

High-dose prolonged combination therapy in non-responders to IFN monotherapy leads to a higher rate of sustained response than the standard combination regimen. Tolerability may be a rate-limiting factor. Maximal effectiveness can be predicted in patients with non-1b genotype and in those who clear HCV-RNA soon after starting retreatment.

Treatment of patients with chronic hepatitis C not responding to interferon with high-dose interferon alpha with or without ribavirin: final results of a prospective randomized trial. Austrian Hepatitis Study Group

OBJECTIVE

To investigate the efficacy of high-dose interferon alpha (IFN-alpha) with or without ribavirin in interferon (IFN) non-responders.

STUDY DESIGN

304 chronic hepatitis C patients received 5 MU IFN-alpha2b (IntronA, Schering-Plough, Kenilworth, NJ, USA) three times a week for 3 months. Non-responders were randomized either to continue with IFN (IFN 5 MU/TIW followed by 10 MU/TIW, each for 3 months) alone (group A: n = 76, m: f = 54: 22, age 45.7 +/- 12 years, 16% cirrhosis, alanine aminotransferase [ALT] 66 +/- 35 U/l) or in combination with ribavirin (approximately 14 mg/kg/day) (group B: n = 81, m: f = 57: 24, age 48.2 +/- 12 years, 17% cirrhosis, ALT 71 +/- 40 U/l). At the end of treatment, patients were followed for 6 months.

MAIN OUTCOME MEASURES

Virological response at end of treatment and 6 months thereafter.

SETTING

University hospitals and tertiary referral centres.

RESULTS

At the end of treatment, eight (10.8%) and 25 (31.3%, P= 0.0066) patients were HCV-RNA negative, and 51 and 39 were HCV-RNA positive, in groups A and B, respectively. There were 17 drop-outs in each group. Six months after treatment, only one patient in group A (1.3%) and seven patients (8.6%, P= 0.06) in group B had normal ALT and undetectable serum HCV-RNA.

CONCLUSIONS

A combination of high-dose IFN with ribavirin induces a short-lasting complete response in about one-third of IFN-non-responders.

Combination therapy with ribavirin and alpha interferon for the treatment of chronic hepatitis C refractory to interferon

BACKGROUND

Up to 80% of hepatitis C patients are refractory to treatment with interferon-alpha. These patients are not likely to benefit from higher dosages or longer duration of interferon alone. The addition of ribavirin has been shown to improve the response rate in patients resistant to a previous course of interferon-alpha alone.

AIM

To evaluate whether a sustained hepatitis C virus (HCV) RNA response could be obtained with combination therapy of interferon-alpha and ribavirin in patients who did not respond to or relapsed after a standard interferon-alpha treatment.

METHODS

A total of 73 patients, 59 non-responders and 14 relapsers after interferon-alpha alone, were treated with a combination of ribavirin (1000-1200 mg/day) and interferon-alpha (3 MU three times a week) for 24 weeks. Alanine aminotransferase levels and HCV RNA were checked for 24 weeks after completion of therapy.

RESULTS

At the end of the combination therapy, 36 patients (49%) showed alanine aminotransferase normalization and in 20 patients (27%), HCV RNA was undetectable in serum. At the end of the 24 weeks follow-up period, only 12 patients (16%) had a sustained response with serum negativity of HCV RNA. This response was significantly higher in relapsers than in non-responders: five (36%) vs. seven (12%) patients (P=0.03), respectively. Adverse effects were restricted to flu-like symptoms and moderate haemolytic anaemia.

CONCLUSIONS

Combination of interferon-alpha and ribavirin is quite limited, both in scope and efficacy, in HCV patients who had a non-response to monotherapy with interferon. Better results may be expected in relapsers, but larger studies are necessary.

High-dose interferon plus ribavirin in chronic hepatitis C not responding to recombinant alpha-interferon

BACKGROUND

Recently, the combination treatment of recombinant alpha-interferon plus ribavirin has been proposed for chronic hepatitis C patients unresponsive to previous therapy with recombinant alpha-interferon alone.

AIM

To determine the effectiveness of the combination therapy for the re-treatment of chronic hepatitis C patients unresponsive to previous interferon therapy. Immediate and long-term follow-up data are reported.

PATIENTS AND METHODS

A series of 100 patients with chronic hepatitis C not responding to recombinant alpha-interferon 3 MU tiw, were randomly assigned to two groups of 50 patients each: Group A, treated with recombinant alpha-interferon therapy for an additional six months but at a double dosage (6 MU tiw) in association with ribavirin. Group B, same treatment as group A but without ribavirin. All patients responsive to therapy were then followed-up for at least 12 months. At the end of the treatment and at the end of the follow-up period, we distinguished between complete responses (return to normal of alanine aminotransferase with undetectable serum HCV-RNA] and biochemical responses (return to normal of alanine aminotransferase still with detectable viraemia).

RESULTS

Side-effects were observed only in patients treated with recombinant alpha-interferon plus ribavirin: 12% discontinued the therapy due to haemolytic anaemia. In group A, the percentages of end-of-treatment complete response, end-of-treatment biochemical response, sustained complete response, and sustained biochemical response, were 38%, 20%, 8%, and 14%, respectively, whilst in group B, these percentages were 12%, 16%, 6%, and 16%, respectively.

CONCLUSION

The results indicate that in patients with chronic hepatitis C unresponsive to previous recombinant alpha-interferon therapy, re-treatment with higher recombinant alpha-interferon doses, either alone or in combination with ribavirin, lead to mild long-term benefit. However, the satisfactory end of treatment complete response in group A suggests that a significant percentage of patients are sensitive to the combination therapy; and that a more aggressive therapeutic protocol in this selected subset of patients could result in a larger number of long-lasting responses leading, in turn, to a more favourable cost-effect ratio.

Retreatment for 24 vs 48 weeks with interferon-alpha2b plus ribavirin of chronic hepatitis C patients who relapsed or did not respond to interferon alone

We assessed the efficacy of interferon (IFN) plus ribavirin over 24 or 48 weeks for the retreatment of patients with chronic hepatitis C who had relapsed or did not respond to a previous course of IFN. One-hundred and twenty patients (69 non-responders and 51 relapsers) were randomly assigned to receive IFN-alpha2b (3 million units thrice weekly) plus ribavirin (1,000-1,200 mg per day) for 24 weeks (group A: 58 patients) or 48 weeks (group B: 62 patients). Treatment was discontinued at week 12 if the alanine aminotransferase (ALT) level remained elevated. The rate of sustained response was 15.5% in group A and 37.1% in group B (P = 0.013). Relapsers treated for 48 weeks had a sustained response rate of 66.6% compared with a sustained response rate of only 25% in those treated for 24 weeks (P = 0.004). Moreover, a sustained response was seen in 14.3% of non-responders treated for 48 weeks and in 8.8% of those treated for 24 weeks (P = 0.71). Fifty-three per cent of patients with a normal ALT level and undetectable hepatitis C virus (HCV) RNA at week 12 had a sustained response compared with 14% of those who were HCV RNA positive at week 12 (P < 0.001). Independent predictive factors of sustained response were: therapy for 48 weeks (P = 0.0026), relapse after IFN treatment (P = 0.0006), loss of HCV RNA at week 12 (P = 0.0008) and HCV genotype non-1 (P = 0.024). Hence, in patients with chronic hepatitis C who failed to respond to a previous course of IFN monotherapy, combination therapy with IFN plus ribavirin for 48 weeks seems to be more effective than IFN plus ribavirin for 24 weeks.

[Chronic hepatitis by C virus. Part 2. Treatment]

Several aspects are revised on the subject related to drugs used, their doses, duration of treatment, different responses obtained, according different types of diseases and patients studied, as the factors able to modify the results obtained.

Early addition of ribavirin to interferon in chronic hepatitis C not responsive to interferon monotherapy

BACKGROUND/AIM

Persistence of HCV-RNA in serum early in treatment is a strong predictor of failure of alpha-interferon therapy for chronic hepatitis C. Therefore, we compared the efficacy of ribavirin addition to alpha-interferon with a doubling of the dosage of alpha-interferon in case of lack of early virological response to alpha-interferon therapy.

METHODS

Sixty patients were administered interferon alpha2b at the dosage of 3 million units 3 times a week. After the first 4 weeks of therapy, serum HCV-RNA was evaluated. The patients with negative HCV-RNA test received the same treatment for a further 11 months, while those with detectable HCV-RNA were randomized to receive either the same dosage of alpha-interferon plus ribavirin (1000 mg/day) or double dosage of alpha-interferon (6 million units tiw) for 11 months. We considered sustained response to be the maintenance of normal alanine aminotransferase and negativity at HCV-RNA testing until the end of a 6-month post-treatment follow-up.

RESULTS

After the first 4 weeks of treatment, 12 (20%) patients showed virological response and 48 patients (80%) remained positive on HCV-RNA testing. Sustained response was observed in 5/12 (42%) patients with early virological response, in 10/24 (42%) patients without early virological response who were administered ribavirin and alpha-interferon, and in only 1/24 (4%) patients who were administered the double dosage of alpha-interferon (p=0.006).

CONCLUSIONS

This study shows the efficacy of the addition of ribavirin to alpha-interferon and the lack of efficacy of doubling the dosage of alpha-interferon in patients without clearance of hepatitis C virus early on in treatment.

The pattern of response to interferon alpha (alpha-IFN) predicts sustained response to a 6-month alpha-IFN and ribavirin retreatment for chronic hepatitis C. TVVH Study Group

BACKGROUND/AIMS

In chronic hepatitis C, interferon-alpha (alpha-IFN) and ribavirin combination therapy improves sustained response compared to alpha-IFN monotherapy, both in naive patients and in previous alpha-IFN relapsers, but the efficacy of such therapy remains limited in non-responder cases. The aim of this study was to assess whether the pattern of response to alpha-IFN alone may predict sustained response to combination therapy during retreatment.

METHODS

Fifty previous alpha-IFN relapsers and 50 previous alpha-IFN non-responders were retreated with a high alpha-IFN dose (6 MU/thrice weekly for 2 months; induction phase) and then randomised to continue with alpha-IFN alone (3 MU/thrice weekly) or to receive combination therapy (3 MU/thrice weekly of alpha-IFN and 1000-1200 mg/daily of ribavirin) for an additional 6 months according to the biochemical response to alpha-IFN shown after the induction phase. All patients were also evaluated for virological and histological response.

RESULTS

Eleven of 25 (44%) relapsers treated with combination therapy and 4/25 (16%) treated with alpha-IFN alone achieved a sustained response. The corresponding figures among non-responders were 1/25 (4%) and 0/25, respectively. Among 26 patients with a complete ALT and HCV-RNA response after 2 months of alpha-IFN, sustained response was seen in 11/14 (79%) treated with combination therapy and in 4/12 (33%) treated with alpha-IFN alone (p=0.05). On the other hand, of 74 cases still HCV-RNA positive after 2 months of alpha-IFN alone, biochemical and virological end of therapy response was better with combination therapy (11/36; 30.5%) compared to alpha-IFN alone (4/38; 10.5%), but only one patient developed a sustained response (1/36; 3%).

CONCLUSIONS

The retreatment with a 6-month combination therapy was associated with a high rate of sustained response only in patients showing a complete biochemical and virological response to alpha-IFN alone. Longer retreatment with combination therapy may be needed to achieve a sustained response in patients without a prompt virological response to alpha-IFN.

Treatment of chronic hepatitis C genotype IV with interferon-ribavirin combination in Saudi Arabia: a multicentre study

Between 1996 and 1997, we conducted a multicentre study to assess the effect of combination therapy of interferon (IFN) + ribavirin on chronic hepatitis C genotype 4. Ninety-seven patients were enrolled. Sixty-eight patients (47 male and 21 female) were non-responders to previous therapy with IFN (Group I). Twenty-nine patients (19 male and 10 female) were new (Group II). Following treatment with IFN, 23% in Group I and 9% in Group II had a sustained biochemical response. Only 12% in Group I and 5% in Group II achieved a sustained virological response. Virus load was found to be the major factor determining response, followed by histology grading and staging. Like HCV genotype 1, HCV genotype 4 seems to have a poor response to therapy.

Combination of ribavirin and interferon-alfa surpasses high doses of interferon-alfa alone in patients with genotype-1b-related chronic hepatitis C

The purpose of this study was to compare interferon-alfa alone (12-month course with high initial doses) with a combination of interferon-alfa and ribavirin in patients infected with genotype 1b. Three hundred and seven patients were randomized into 3 groups to receive 6 mega units (MU) of interferon-alfa-2b subcutaneously 3 times weekly for 6 months followed by 3 MU for 6 months (n = 95, group A); 10 MU for 3 months followed by 6 MU for 3 months, followed by 3 MU for 6 months (n = 83, group B); or the group-A schedule in combination with ribavirin (n = 129, group C) for 4 (n = 46), 6 (n = 44), or 12 months (n = 39). Negative polymerase chain reaction (PCR) was more frequent in group C than in groups A or B after 3 months of treatment (P <.006), at the end of treatment (P =.017), and at the end of follow-up (32.8%, 16.9%, and 14.1%, respectively, P <.003). A complete response (negative PCR and normal alanine transaminase) was higher in group C than in the other groups and when comparing 12- to 4- and 6-month combination therapy at the end of treatment (P =.05) and of follow-up (45.2% vs. 25.4%, respectively, P =.05). The greater efficacy of the combination was related to the higher rate of primary virological response and also to a decrease in the percentage of breakthrough and of relapse. In 1b-infected patients, the combination of high doses of interferon-alfa (6 MU) and ribavirin for 12 months appears to be the best therapy, with a high rate of sustained response.

Hepatitis C: retreatment and treatment of patients with renal failure

This paper addresses two difficult issues in the treatment of hepatitis C: patients who fail to achieve a sustained response after the first course of treatment, and those who simultaneously suffer from chronic renal failure. With the recent improvements in firstline treatment, retreatment is mainly applicable to those who have previously received 6-month of interferon monotherapy at 3 MU thrice weekly. For those who had an end-of-treatment response but relapsed, there is a choice between interferon monotherapy at increased dose and/or duration of treatment, or a 6-month course of combination therapy. Retreatment of non-responders is generally unsuccessful, but some patients may respond to interferon-alpha 3 MU and ribavirin 1.0-1.2 g/day. For patients with chronic renal failure and hepatitis C, combination treatment is not possible because ribavirin is contraindicated. Interferon given at a dose of 1.5 MU thrice weekly was reported to be fairly well tolerated by patients who were on dialysis and resulted in end-of-treatment and sustained biochemical and virological response in some cases. Interferon given in the usual doses may be associated with severe adverse effects in patients with renal failure, and can precipitate allograft rejection in patients who have undergone renal transplantation.

Methodological issues in papers on IFN therapy: time for reappraisal

We conducted an analytical review of 194 full papers on interferon (IFN) therapy for chronic hepatitis C to evaluate current methodology (i.e. study design, criteria for evaluating the efficacy of therapy and predictors of response). Of the papers evaluated, 64 were randomized controlled trials (RCT), 40 were non-randomized controlled trials (NRCT) and 90 were observational studies (OS). The methodological analysis was focused mainly on clinical trials. The number of patients enrolled in RCT was higher compared with the number enrolled in NRCT. Uniform enrolment criteria were used in less than 50% of the trials. Only 20% of RCT and 2.5% of NRCT used criteria for defining sample size. The response rate was calculated on an intention-to-treat basis in 36 of the RCT and in 14 of the NRCT. The outcome of treatment and the criteria employed to define the response to treatment were found to be far from standardized. In 51.5% of the RCT and 42.5% of the NRCT, normalization of alanine aminotransferase (ALT) level at the end of follow-up was the only marker of response studied. Only 57.6% of the trials considered histological evidence as an important outcome. Among the clinical trials, 71.1% evaluated predictors of good response to IFN therapy. In 51% of the OS, ALT normalization by the end of follow-up was the only criterion for defining response. In conclusion, to ensure a high level of reliability in comparing or combining the results of different studies, some basic general requirements must be followed when planning trials on antiviral therapy.

Interferon alfa-2b plus ribavirin for chronic hepatitis C patients who have not responded to interferon monotherapy

BACKGROUND

The role of combination therapy is poorly defined in chronic hepatitis C patients who are non-responders to interferon.

AIM

To assess the efficacy, safety and tolerance of interferon alfa-2b plus ribavirin in chronic hepatitis C patients who do not respond to interferon monotherapy.

METHODS

A total of 127 non-responder patients with chronic hepatitis C received 3 mU t.i.w. of interferon alfa-2b plus 1000-1200 mg ribavirin daily for 48 weeks. Effects of therapy were evaluated by serum aminotransferases and hepatitis C virus (HCV) RNA levels.

RESULTS

Twenty-nine (23%) patients had an end-of-treatment response. Six months after treatment, 20 (16%) patients were sustained responders. Early loss of HCV RNA was the strongest predictor of a sustained response (P < 0.0001). Remission was also more frequent in patients with genotype 1b (P < 0.02), elevated alanine aminotransferase (P < 0.03) and low gamma glutamiltranspeptidase (P < 0.002). Treatment was discontinued in 21 (17%) patients: in 14 for intolerance and in seven due to side-effects.

CONCLUSIONS

Combination therapy with interferon plus ribavirin produced a sustained response in 16% of chronic hepatitis C patients who were non-responders to interferon. This combination was safe and well tolerated.

Current therapy for chronic hepatitis C

Chronic hepatitis C virus infection is common in the United States with an estimated prevalence of 2.7 million persons. Fortunately, the incidence of new infections has markedly declined in recent years and the natural history of chronic hepatitis usually only results in significant progression after several decades of infection. However, the majority of chronically infected patients acquired their infections more than 20 years ago; these patients with long-standing chronic hepatitis are now presenting in increasing numbers with decompensated cirrhosis and the need for liver transplantation. Cirrhosis caused by chronic hepatitis C is now the most common indication for liver transplantation. Interferon monotherapy became clinically available 10 years ago but resulted in sustained improvement in liver disease and durable loss of detectable virus in fewer than 10% of treated patients. The recent use of the combination of interferon with the nucleoside analogue ribavirin for 6-12 months results in a sustained virological response in 30%-40% of previously untreated patients. The response to this combination therapy is also excellent in patients who had initially responded to interferon monotherapy and later relapsed. Furthermore, some recent studies suggest that a small proportion of patients who failed to respond to a prior course of interferon (primarily noncirrhotic patients with low levels of virus and genotypes other than 1) may also benefit from retreatment with this combination.

Interferon plus ribavirin in chronic hepatitis C non-responders to recombinant alpha-interferon

The aim of this study was to evaluate the most appropriate therapeutic protocol for patients with chronic hepatitis C not responding to a previous course of recombinant interferon alpha-2b (rIFN). Sixty patients were randomly assigned to two groups of 30 subjects each: group A was treated with double dose of the same type of rIFN (6 MU t.i.w.) plus ribavirin for 6 months; group B was treated with the same rIFN dose and duration as group A, but without ribavirin. An end of treatment complete response (ETCR) was defined as alanine transaminase (ALT) normalization with undetectable serum HCV-RNA at the end of the treatment, while an end of treatment biochemical response (ETBR) as ALT normalization with still detectable viraemia. The two groups were homogeneous. The patients with ETCR or ETBR were than followed-up for at least 1 year. A sustained biochemical response (SBR) was defined as the persistence of normal ALT with still detectable viraemia after a 12-month follow-up, and a sustained complete response (SCR) as the persistence of normal ALT with undetectable viraemia. Side-effects were only observed in patients treated with rIFN plus ribavirin: four cases (13%) discontinued the therapy owing to haemolytic anaemia. Combination therapy induced an ETCR in 11 patients (37%) and an ETBR in six (20%), while a SCR was observed in two subjects (7%) and a SBR in four (13%). The use of a double dose of rIFN alone obtained an ETCR in four cases (13%) and an ETBR in five (17%), with a SCR in two (7%) and a SBR in three (10%). Hence, both combination therapy and single treatment with higher rIFN doses were unable to show statistically significant long-term benefits in patients with chronic hepatitis C resistant to a previous course of rIFN treatment.

Mixed cryoglobulinaemia associated with hepatitis C virus infection: a predictor factor for treatment with interferon?

BACKGROUND AND AIMS

Mixed cryoglobulinaemia (MC) is a frequent finding among patients infected with hepatitis C virus (HCV). The response to treatment with alpha-interferon (alpha-IFN) in these patients is linked to predictive factors. The aim of this study was to ascertain whether the presence of MC was a predictive factor of response in patients treated with alpha-IFN for chronic hepatitis due to HCV.

METHODS

Thirty-two patients with MC and HCV infection (24 with chronic hepatitis and eight with cirrhosis) were compared with 30 patients with HCV infection without MC (23 chronic hepatitis, seven cirrhosis) of a similar mean age. All were treated with lymphoblastoid alpha-IFN, at 3 MU, t.i.w., for 6-12 months and then followed up.

RESULTS

No statistical difference was observed between the two groups in terms of sustained response (P = 0.83), relapse (P = 0.88) and non-response (P = 0.92). The mean follow up was 24.3 months (range 17-28) for patients with sustained response and for the patients with MC and 22.6 months (range 15-26) for patients without MC.

CONCLUSIONS

The presence of cryoglobulinaemia does not influence the response to alpha-IFN in patients with chronic HCV infection.

Combination treatment with interferon and ribavirin for chronic hepatitis C

Interferon was the first drug shown to be effective in patients with chronic hepatitis C, but initial treatment regimens achieved sustained loss of virus in only a small minority of patients. The combination of IFN with ribavirin now makes sustained response rates of 30% to 40% possible. This is quite a remarkable achievement for a pharmacologic treatment of a chronic viral infection. It is now reasonable to assume that early treatment and eradication of chronic hepatitis C might reduce the growing burden of hepatitis C and its complications on the healthcare system. Future researchers will strive to optimize combination treatment regimens. Longer treatment courses and intensified induction regimens using either daily dosing, high doses, or both may improve long-term response, but this remains speculative. Other forms of IFN may improve response or increase the ease of drug administration. Conjugation of biologic compounds to polyethylene glycol can result in significant prolongation of plasma half-life while maintaining the properties of the parent molecule. Some biologic properties may be altered, however, so pegylated IFN must continue to be evaluated in clinical trials. There is limited clinical data on other recombinant or natural interferons in combination with oral ribavirin, however, these may prove to be equally effective. Combinations of IFN with one or more other antiviral, anti-inflammatory, or immune modulatory agents will need to be studied. Although amantidine is not effective against hepatitis C as a single agent or in combination with IFN, the combination of IFN, ribavirin, and rimantidine has been shown to have antiviral activity superior to the IFN-ribavirin combination against influenza virus and possibly against HCV.

Interferon-ribavirin for chronic hepatitis C with and without cirrhosis: analysis of individual patient data of six controlled trials. Eurohep Study Group for Viral Hepatitis

BACKGROUND & AIMS

The aim of this study was to compare interferon (IFN)-ribavirin combination therapy with IFN monotherapy in chronic hepatitis C with particular focus on its efficacy in cirrhosis.

METHODS

A multivariate analysis of individual patient data of all randomized controlled trials using an IFN-ribavirin arm, reported between 1991 and March 1998, was performed. Centers included 1 Asian and 5 European university-based referral centers for liver disease. A total of 197 patients with chronic hepatitis C received IFN-alpha (3 MU three times weekly) and ribavirin (1-1.2 g daily) for 6 months, and 147 patients received IFN-alpha (3 MU three times weekly) for 6 months. Patients were characterized according to previous IFN therapy, presence of cirrhosis, and genotype 1. Efficacy of therapy was evaluated by assessing the sustained response rate by logistic regression analysis.

RESULTS

Patients without cirrhosis treated with IFN-ribavirin had a significantly higher sustained response rate than those treated with IFN, approximately 3-fold for previously untreated patients (IFN-ribavirin: genotype 1, 33%; genotype 2/3, 65%; IFN: genotype 1, 8%; genotype 2/3, 24%). In cirrhosis, sustained response rates with IFN-ribavirin (previously untreated: genotype 1, 7%; genotype 2/3, 24%) were also significantly higher than those with IFN (previously untreated: genotype 1, 1%; genotype 2/3, 5%). Clinical relevant superiority of combination therapy over IFN monotherapy was also observed for relapse; the same trend was observed for nonresponders. Tolerance for IFN-ribavirin was similar for patients with or without cirrhosis.

CONCLUSIONS

Combination with ribavirin significantly enhances the sustained response rate of IFN therapy in major patient types (cirrhosis, genotype 1) with chronic hepatitis C. Thus, IFN-ribavirin combination is likely to become the antiviral therapy of choice for cirrhosis caused by hepatitis C.

A randomized trial of ribavirin and interferon-alpha vs. interferon-alpha alone in patients with chronic hepatitis C who were non-responders to a previous treatment. Multicenter Study Group under the coordination of the Necker Hospital, Paris, France

BACKGROUND/AIM

Fifty percent of patients infected with hepatitis C virus (HCV) show no response to alpha-interferon, and no alternative therapy has thus far proven to be effective. Therapeutic combination with ribavirin and alpha-interferon has shown promising results in naive patients and in relapsers, but based on limited series, it was reported to be inefficient in non-responders. The aim of our study was therefore to explore and compare, in a randomized trial, the tolerance and potential efficacy of alpha-interferon alone with a sequential combination of ribavirin and the same alpha-interferon regimen in those patients.

METHODS

Sixty-four non-responder patients were randomized in the alpha2b-interferon group (a 6-month course at a dosage of 6 MU followed by a 6-month course of 3 MU three times weekly subcutaneously) and 62 in the "combination" group (sequential combination of the same alpha2b-interferon therapy preceded by a 2-month course of ribavirin which was then associated for 2 months with alpha2b-interferon at a daily dosage of 1.0 or 1.2 g).

RESULTS

Treatment withdrawal was necessary for six patients from the alpha-interferon and eight patients from the combination group. Normalization of aminotransferase activities was significantly more frequent after the 4-month course of ribavirin with 2 months of interferon than after 2 months of interferon alone (52.8 vs. 26.2%, p<0.01), but this difference was not maintained after ribavirin withdrawal. Disappearance of serum HCV RNA (PCR) was significantly more frequent at the end of treatment in the combination group (24.5 vs. 7.7%, p=0.02), but did not differ 6 months after the end of therapy (9.8 and 8.3%, respectively). The long-term response was not associated with liver status (cirrhosis vs. absence of cirrhosis) or genotype. Mean viremia was significantly lower in long-term responders than in non-responders or relapsers in both groups (p<0.001 for the interferon group and p<0.05 for the combination group), but the large extent of viral load precluded reliable prediction. The pre- and post-treatment hepatitis activity index did not differ between the two groups. While a crude histopathological improvement in the hepatitis activity index for a given patient was more frequently observed in the combination group (69.2 vs. 35.9%, p<0.01), improvement as defined by a decrease of at least 2 in the hepatitis activity index was significant only for lobular necrosis and degeneration.

CONCLUSIONS

This study demonstrates the efficacy of the combination of ribavirin/alpha-interferon in non-responders. Indeed, (i) it is fairly tolerated; (ii) it increases the rate of the initial biological response, and of the virological response by decreasing breakthrough, though this benefit is not sustained; and (iii) it induces a significant histological improvement in necrosis. A simultaneous and prolonged combination of ribavirin/alpha-interferon should be further evaluated in non-responders.

Interim analysis of a randomized controlled trial of combination of ribavirin and high dose interferon-alpha in interferon nonresponders with chronic hepatitis C

This trial investigated the efficacy of a combination of high-dose interferon-alpha (IFN-alpha) with ribavirin in IFN nonresponders.

STUDY PROTOCOL

304 patients with chronic hepatitis C were treated with 5 MU IFN-alpha2b (IntronA(R), Schering-Plough) per TIW for 3 months. Nonresponders (defined by HCV-RNA positivity in serum after the 3 months of therapy) were randomized either to continue with IFN (5 MU IFN per TIW followed by 10 MU per TIW for each 3 months) alone (group A) or in combination with ribavirin (1-1.2 g per day) (group B). ALT was measured in monthly intervals, HCV-RNA in 3 monthly intervals. Pretreatment characteristics of the randomized patients were as follows: group A, n = 76; m/f, 54/22; 16% cirrhosis, age, 45. 7 +/- 12 years; ALT (U per litre), 66 +/- 35; group B, n = 81; m/f, 57/24; 17% cirrhosis, age, 48.2 +/- 12; ALT, 71 +/- 40. After 9 months of treatment, nine (11.6%) and 27 (32.5%, P = 0.0066) patients were HCV-RNA negative and 51 and 39 were HCV-RNA positive, in groups A and B, respectively. There were 17 drop-outs in group A and 15 in group B. Six months after treatment only two patients in group A (2.5%) and five (6%, P = 0.06) in group B had normal ALT and no detectable HCV-RNA in serum. In addition to the well-known side-effects of IFN the mean haemoglobin concentration dropped by 2 g per litre in group B. These data indicate that a combination of high-dose IFN with ribavirin is effective in inducing a short-lasting complete response in one-third of IFN nonresponders. Prolonged treatment with IFN/ribavirin may be necessary to obtain a sustained response.

Interferon-alpha plus ribavirin in chronic hepatitis C resistant to previous interferon-alpha course: results of a randomized multicenter trial

BACKGROUND/AIMS

Interferon-alpha plus ribavirin seem to be more efficacious than interferon monotherapy in chronic hepatitis C. In a multicenter randomized trial, we evaluated the efficacy of this association for interferon-alpha resistant chronic hepatitis C.

METHODS

Fifty patients who were non-responders to recombinant or lymphoblastoid interferon-alpha were randomized to receive either ribavirin (800 mg/day) plus leucocytic interferon-alpha (3 mega units thrice weekly) or the same dose of interferon-alpha alone, for 6 months. Effects of therapy were evaluated by serum aminotransferase and hepatitis C virus RNA levels and control liver biopsies.

RESULTS

At the end of treatment, aminotransferase levels become normal in 9/26 patients receiving combination therapy (35% [confidence interval, 16% to 53%]) and in 2/24 receiving interferon-alpha alone (8% [confidence interval, -3% to 19%]) (p = 0.03). Aminotransferase normalization was never associated with hepatitis C virus RNA clearance. All patients with normal aminotransferase relapsed after discontinuation of therapy. At the end of treatment, mean hepatitis C virus RNA levels significantly decreased only in the group receiving combination therapy, but returned to pretreatment values 6 months thereafter. No histological improvement was observed in either group.

CONCLUSIONS

There is no indication for treatment with interferon-alpha at the dose of 3 mega units thrice weekly plus 800 mg/day of ribavirin for 6 months in chronic hepatitis C resistant to interferon-alpha.

Paricalcitol Injection and Ribavirin/Interferon Alfa-2b

Each month, subscribers to The Formulary® receive print and electronic versions of at least six monographs reviewing new drug entities or related drugs within a category. Some reviews take a second look at currently available drugs, whereas other preliminarily evaluate agents about to be released–just in time for use with your Pharmacy and Therapeutics Committee or for counter detailing. The monographs are prepared by clinical and drug-information pharmacists and are reviewed by expert pharmacists and physicians. Through the cooperation of The Formulary, Hospital Pharmacy has arranged to publish selected reviews in this column. If you would like more information about The Formulary or its related electronic bulletin board, known as the F.I.X.® (Formulary Information Exchange, write to: The Formulary, 33971 Selva Road, Suite 250, Dana Point CA 92629; or call 1-800-322-4349.

Treatment of chronic hepatitis C: impact of combination therapy

Interferon as a single agent results in normalization of the serum alanine aminotransferase (ALT) levels, loss of detectable serum hepatitis C virus RNA, and histologic improvement in approximately 40% of patients. However, regardless of the duration of initial therapy, most patients relapse within the first few months after the drug is stopped, and only a small proportion have a sustained response. Ribavirin is a nucleoside analogue that is known to have in vitro activity against a number of both RNA and DNA viruses. As a single agent, oral ribavirin treatment transiently lowers serum ALT values into the normal range in about 40% of cases of chronic hepatitis C, but it does not affect the level of viremia. However, when given in combination with interferon for 6 to 12 months, ribavirin results in a sustained normalization of serum ALT levels and loss of detectable hepatitis C virus RNA in 30% to 40% of previously untreated patients. Retreatment of interferon relapsers with the combination of interferon and oral ribavirin for 6 months results in a sustained viral-negative response in about half of patients. Thus far, there is little evidence that combination therapy is effective in patients in whom ALT fails to normalize and who have lost hepatitis C virus RNA during a previous treatment course (nonresponders). Studies are ongoing in this group.