Effects of ribavirin on intrahepatic and extrahepatic expression of hepatitis C virus in interferon nonresponsive patients

Alterations in the iron homeostasis network: A driving force for macrophage-mediated hepatitis C virus persistency

Mechanisms that favor Hepatitis C virus (HCV) persistence over clearance are unclear, but involve defective innate immunity. Chronic infection is characterized by hepatic iron overload, hyperferraemia and hyperferittinaemia. Hepcidin modulates iron egress via ferroportin and its storage in ferritin. Chronic HCV patients have decreased hepcidin, while HCV replication is modified by HAMP silencing. We aimed to investigate interactions between HCV and hepcidin, during acute and chronic disease, and putative alterations in cellular iron homeostasis that enhance HCV propagation and promote viral persistence. Thus, we used HCV JFH-1-infected co-cultures of Huh7.5 hepatoma and THP-1 macrophage cells, HCV patients' sera and Huh7 hepcidin-expressing cells transfected with HCV replicons. Hepcidin levels were elevated in acutely infected patients, but correlated with viral load in chronic patients. HAMP expression was up-regulated early in HCV infection in vitro, with corresponding changes in ferritin and FPN. Hepcidin overexpression enhanced both viral translation and replication. In HCV-infected co-cultures, we observed increased hepcidin, reduced hepatoma ferritin and a concurrent rise in macrophaghic ferritin over time. Altered iron levels complemented amplified replication in hepatoma cells and one replication round in macrophages. Iron-loading of macrophages led to enhancement of hepatic HCV replication through reversed ferritin "flow." Viral transmissibility from infected macrophages to naïve hepatoma cells was induced by iron. We propose that HCV control over iron occurs both by intracellular iron sequestration, through hepcidin, and intercellular iron mobilisation via ferritin, as means toward enhanced replication. Persistence could be achieved through HCV-induced changes in macrophagic iron that enhances viral replication in these cells.

Molecular Targets in Inhibition of Hepatitis C Virus Replication

Hepatitis C virus (HCV) is the major cause of transfusion-associated hepatitis and accounts for a significant proportion of hepatitis cases worldwide. Most, if not all, infections become persistent and about 60% of cases develop chronic liver disease with various outcomes ranging from an asymptomatic carrier state to chronic active hepatitis and liver cirrhosis, which is strongly associated with the development of hepatocellular carcinoma. Since the initial cloning of the viral genome in 1989, our knowledge of the molecular biology of HCV has increased rapidly and led to the identification of several potential targets for antiviral intervention. In contrast, the low replication of the virus in cell culture, the lack of convenient animal models and the high genome variability present major challenges for drug development. This review will describe candidate drug targets and summarize ‘classical’ and ‘novel’ approaches currently being pursued to develop efficient HCV-specific therapies.

Pharmacological and biological antiviral therapeutics for cardiac coxsackievirus infections

Subtype B coxsackieviruses (CVB) represent the most commonly identified infectious agents associated with acute and chronic myocarditis, with CVB3 being the most common variant. Damage to the heart is induced both directly by virally mediated cell destruction and indirectly due to the immune and autoimmune processes reacting to virus infection. This review addresses antiviral therapeutics for cardiac coxsackievirus infections discovered over the last 25 years. One group represents pharmacologically active low molecular weight substances that inhibit virus uptake by binding to the virus capsid (e.g., pleconaril) or inactivate viral proteins (e.g., NO-metoprolol and ribavirin) or inhibit cellular proteins which are essential for viral replication (e.g., ubiquitination inhibitors). A second important group of substances are interferons. They have antiviral but also immunomodulating activities. The third and most recently discovered group includes biological and cellular therapeutics. Soluble receptor analogues (e.g., sCAR-Fc) bind to the virus capsid and block virus uptake. Small interfering RNAs, short hairpin RNAs and antisense oligonucleotides bind to and led to degradation of the viral RNA genome or cellular RNAs, thereby preventing their translation and viral replication. Most recently mesenchymal stem cell transplantation has been shown to possess antiviral activity in CVB3 infections. Taken together, a number of antiviral therapeutics has been developed for the treatment of myocardial CVB infection in recent years. In addition to low molecular weight inhibitors, biological therapeutics have become promising anti-viral agents.

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.

Elevations in alanine aminotransferase levels late in the course of antiviral therapy in hepatitis C virus RNA-negative patients are associated with virological relapse

The incidence and clinical meaning of elevated alanine aminotransferase (ALT) in chronic hepatitis C patients who are hepatitis C virus (HCV)-RNA negative during pegylated interferon (PEG-IFN) and ribavirin therapy have not been completely characterized. In this study our aim was to assess the incidence, pattern, predictive factors, and clinical meaning of elevated ALT in a cohort of 173 chronic hepatitis C patients who obtained viral clearance during either PEG-IFNalpha2(a) or alpha2(b) and weight-based ribavirin therapy. Patients were defined sustained viral responders (SVRs) or relapser responders (RRs) on the basis of a serum HCV-RNA result at 24-week follow-up. SVR and RR were obtained in 141 (58%) and 32 patients (13%), respectively. Among the 173 study patients, 57 patients (33%) had undetectable serum HCV-RNA and elevated ALT in at least one evaluation (weeks 2, 4, 12, 24 in all genotypes, and week 48 in HCV genotype 1 and 4 alone), and this phenomenon was not differently distributed between SVRs and RRs. No pretreatment demographic (age, gender), clinical (ALT levels, histological grade and stage, body mass index) and viral (load, genotype) parameter was associated with this phenomenon. The incidence of elevated ALT levels was not associated with type of PEG-IFN and ribavirin dose. Elevated ALT levels showed a different longitudinal pattern, occurring more frequently between week 12 and the end of treatment in RR as compared to SVR patients (90% versus 9%, P = 0.000001).

CONCLUSION

The occurrence of elevated ALT levels in HCV-RNA-negative patients during PEG-IFN and ribavirin therapy is a fairly frequent and unpredictable phenomenon. Although ALT elevation per se is not associated with a greater risk of relapse, its occurrence in the later phases of therapy is more common in relapsing patients.

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.

Convert hepatitis C virus into a non-enveloped virus like hepatitis A, by targeting its envelope rather than the RNA

Based on the current understanding of the differences between the structure of hepatitis C virus (HCV) in one hand and the hepatitis A and E viruses (HAV and HEV) in the other hand, we hypothesize that converting the HCV into a non-enveloped virus may be the required key step in allowing viral clearance and preventing chronic viremia. Better understanding of the structure of HCV envelop, and of the mechanisms involved in its acquisition is essential for the development of agents that can interfere with "envelopization" of the newer copies of HCV RNA genome.

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.

Retreatment with interferon and ribavirin vs interferon alone according to viraemia in interferon responder-relapser hepatitis C patients: a prospective multicentre randomized controlled study

Low pretreatment viral load has consistently been shown to be an independent predictor of sustained response (SR) in patients with chronic hepatitis C infection. We assessed the efficacy of interferon (IFN) plus ribavirin vs IFN alone in low viraemic patients (<2 millions copies/mL) who had relapsed to a previous course of IFN and the efficacy of 24 vs 48 week combination therapy in high viraemic patients. Two hundred and ninety-seven patients were randomly assigned to one of the four regimens after stratification on pretreatment viral load. All patients received IFN-alpha2b (6 million units thrice weekly for 24 weeks and 3 million units thrice weekly for 24 weeks). Patients with low viraemia received either IFN-alpha2b alone for 48 weeks (R1: 42 patients) or IFN-alpha2b plus ribavirin (600 mg/day) for 24 weeks and IFN-alpha2b alone for the next 24 weeks (R2: 48 patients). Patients with high viral load received either IFN-alpha2b plus ribavirin for 24 weeks and then IFN-alpha2b alone for the next 24 weeks (R3: 104 patients) or IFN-alpha2b plus ribavirin for 48 weeks (R4: 103 patients). In low viraemic patients the rate of SR was 37.7% in group R1 and 59.6% in group R2 (P < 0.05). In high viraemic patients, the rate of SR was 44.7% in group R3 and 51.4% in group R4 (P: NS). Thirty-one patients discontinued treatment (10.4%) without difference regarding treatment regimen. In the regimen using ribavirin we found no difference in terms of SR between patients receiving a dose of ribavirin below 10.6 mg/kg/day (55%) or over 10.6 mg/kg/day (58%). Histological improvement occurred in 70.2% of patients regardless of the regimen. Logistic regression showed that genotype 2 and 3, Knodell score <6 and alanine aminotransferase pretreatment level >3 x upper limit of normal were significantly and independently correlated with SR. In low viraemic patients who relapsed to a previous IFN treatment, combination therapy using high-dose IFN and low-dose ribavirin is better than high-dose IFN alone. In high viraemic patients there was no benefit in increasing the duration of combination therapy from 24 to 48 weeks. In this study, it was found that low dose of ribavirin can be used safely and there is no effect of ribavirin dose on SR.

Is delayed normalization of alanine aminotransferase a poor prognostic predictor in chronic hepatitis C patients treated with a combined interferon and ribavirin therapy?

BACKGROUND AND AIMS

Decreased alanine aminotransferase (ALT) level is the accepted basic indicator of an interferon (IFN) therapeutic effect in chronic hepatitis C. This study assessed whether delayed normalization of ALT predicts a poor response to a combined therapy of IFN and ribavirin in patients with chronic hepatitis C virus (HCV) infection.

METHODS

Patients were treated with IFN-alpha 2b three times weekly and oral ribavirin for 24 weeks. The ALT values were assessed monthly and patterns of changes in ALT activity were analyzed. Serum HCV-RNA was checked at weeks 0, 12, 24, and 48.

RESULTS

A total of 103 patients completed therapy and 69 (67%) of them achieved a sustained viral response (SVR). There was no significant difference in the SVR between patients with or without early normalization (week 12) of ALT level (69 vs 56%). Of the sustained responders, nine patients (13%) with delayed ALT normalization had a SVR. Nine of the 12 patients (75%) with abnormal ALT and negative HCV-RNA at week 12 had a SVR compared with none of four patients who had positive HCV-RNA at week 12 (P = 0.0192).

CONCLUSIONS

Lack of normalization of the ALT level at week 12 does not preclude successful virological outcome in hepatitis C patients receiving a combined therapy of IFN and ribavirin. Hepatitis C virus RNA at week 12 may be a useful predictor of treatment outcome in patients without early biochemical response.

Early viral clearance and sustained response in chronic hepatitis C: a controlled trial of interferon and ribavirin after high-dose interferon induction

High-dose induction with alpha-interferon induces early viral clearance of hepatitis C and combined with ribavirin enhances sustained response. We assess whether adding ribavirin after viral clearance obtained by alpha-interferon induction increased the rate of viral eradication.Forty-one naïve patients with chronic hepatitis C were randomised to receive, after 4 weeks of 10 mU daily of alpha-interferon (induction), 3 mU daily for 22 weeks and 3 mU thrice weekly for 26 weeks of either interferon alone (monotherapy) or interferon plus 1000-1200 mg daily of ribavirin (combination therapy). At the end of the induction phase, 23 (56%) subjects had cleared HCV-RNA. During therapy, breakthrough was observed in four patients on monotherapy, but never in patients on combination therapy. The rate of clearance of HCV-RNA was different between monotherapy and combination therapy at the end of treatment (40% vs. 76.1%, P=0.02) and at the end of follow-up (5% vs. 57.1%, P=0.001). Twelve of the 23 patients who cleared HCV-RNA during induction, but only one of the 18 still HCV-RNA-positive after 4 weeks of therapy, had a sustained response (52.2% vs. 5.6%, P=0.001). Clearance of HCV-RNA at 1 week had a high positive predictive value for sustained response in combination therapy (PPV=0.75), but not in monotherapy (PPV=0.33). Induction with high daily doses of alpha-interferon obtains suppression of hepatitis C in more than half of patients, but ribavirin is needed to maintain a sustained response. The rate of sustained response is a function of the time to HCV-RNA clearance. In patients not responding to induction therapy addition of ribavirin does not obtain a sustained virological response.

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.

Combined treatment of relapse of chronic hepatitis C with high-dose alpha2b interferon plus ribavirin for 6 or 12 months

BACKGROUND/AIMS

Retreatment of relapses of chronic hepatitis C with a standard regimen of interferon plus ribavirin for 6 months obtains a sustained response in a minority of patients with high viraemia and genotype 1b. We aimed to assess whether increasing the interferon dose and prolonging the time of combined treatment may enhance the effectiveness, and also to evaluate the tolerability, and to identify the determinants of sustained response.

METHODS

Fifty subjects with chronic hepatitis C who had relapsed after one or more courses of a-interferon monotherapy were randomised to receive alpha2b interferon (6 MU tiw) plus ribavirin (1000-1200 mg daily) for 6 or 12 months. ALT normalisation and serum HCV-RNA clearance at the end of treatment and 6 months after stopping therapy were used as markers for sustained response.

RESULTS

End-of-treatment response was achieved in 48 patients (96%) and 27 (54%) had a complete sustained response. Patients treated for 12 months had a higher rate of sustained response (18/25, 72%; 95% C.I. 0.54-0.89) than those treated for 6 months (9/25, 36%; 95% C.I. 0.17-0.55, p=0.01). Twelve months of therapy was significantly more effective for patients with genotype 1b and baseline serum HCV-RNA greater than 450 000 copies/ml (p=0.005). Seven subjects (14%) discontinued treatment because of side effects. Logistic regression analysis showed 12 months of therapy, young age and low pre-treatment serum HCV-RNA to be independent predictors of sustained response.

CONCLUSIONS

Relapsers with genotype 1b and high levels of HCV-RNA will benefit from a 12-month course of 6 MU tiw interferon plus ribavirin, while subjects with genotype 1b and low levels of serum HCV-RNA or with genotype other than 1b may be treated for 6 months.

Combination treatment for chronic hepatitis C: what is the role of ribavirin?

Ribavirin in combination with interferon-alpha2b is the new standard for chronic hepatitis C (CHC) treatment. Although usually considered as an antiviral compound, this guanosine analogue shows some additional effects on the immune system that could largely contribute to its clinical efficacy in CHC. Numerous in vitro experiments demonstrate that ribavirin has a selective down-regulatory effect on TH2 cytokine release with, in some cases, a concomitant TH1 cytokine up-regulation. In vivo, combination treatment of CHC patients was shown to induce a predominant TH1 response in isolated PBMCs, but also a reduction of peripheral TH2 response. Considering that: 1) a strong CD(4)+ helper T-cell response is associated with viral clearance in acutely infected patients; 2) a weak T-cell response to the viral antigens is common in chronic infected patients; 3) responding patients to combination treatment (but not non-responding patients) altered their cytokine profile under treatment, either to express IFN-gamma or to reduce pro-inflammatory mediators; it is highly presumed that ribavirine participates to restore an efficient T-cell response and to reduce the non-specific inflammatory cytolytic activity during CHC combination treatment.

Response to retreatment with interferon-alpha plus ribavirin in chronic hepatitis C patients is independent of the NS5A gene nucleotide sequence

OBJECTIVE

Interferon-alpha plus ribavirin is an effective treatment for chronic hepatitis C patients. We evaluated whether the response to this combined therapy correlated with the presence of mutations in a region of 372 nucleotides within the NS5A gene.

METHODS

Sixty-two patients, 42 nonresponders and 20 relapsers to a previous course of interferon-alpha, received 3 million units thrice weekly of interferon-alpha-2b and 1-1.2 g daily of ribavirin for 12 months. Basal biochemical and virological (HCV RNA and genotype) parameters were determined. Clinical examinations were carried out at 1, 2, 3, 6, and 12 months. In addition, nucleotide sequencing of the NS5A gene was determined for viral samples obtained from 38 of these patients at the baseline of the combined therapy, as well as in 15 of them before initiating the previous course of interferon as monotherapy.

RESULTS

On finishing the 12 months, 36 patients (58.1%) had normal aminotransferases and 25 (40.3%) cleared viremia. Nucleotide sequencing indicated the same level of genetic variability within the group of responder and nonresponder patients all along the 124 amino acid residues of the NS5A gene studied. Neither the type of amino acid substitution nor the number of them was significantly different in one group relative to the other.

CONCLUSIONS

Therapy with interferon-alpha-2b plus ribavirin was well tolerated, achieving an end-of-treatment response in 25 (40.3%) patients. Response did not correlate with the presence of mutations in the NS5A gene analyzed, including the interferon sensitivity determining region (ISDR) and its flanking sequences.

Interferon versus ribavirin plus interferon in chronic hepatitis C previously resistant to interferon: a randomized trial

BACKGROUND

More than 70% of patients with chronic hepatitis C are resistant to interferon therapy. Ribavirin, in association with interferon, has been demonstrated as effective, at a dose of 800-1200 mg/day, but the efficacy of a lower dose has not been established.

METHODS

We assessed the effectiveness of the combination of 600 mg/day of ribavirin plus 3 MU of interferon over a period of 6 months, in a group of patients previously resistant to interferon. Sixty-two patients with chronic hepatitis C with serum and hepatic HCV RNA relapsers or non-responders to interferon, were randomly divided into two groups: group A received 3 MU of interferon alpha-2b, three times a week for 6 months; group B was given the same dose plus 600 mg per day of ribavirin for 6 months. Two patients from each group dropped from therapy. One patient from group A and two from group B withdrew from treatment because of adverse effects.

RESULTS

Mean alanine aminotransferase levels were similar in both groups throughout the study. A sustained response was observed in 7% and 7.4% of groups A and B with short-term response in 39% and 59%, and no response in 54% and 34% from both groups respectively (non-significant). At 12 months, 4 and 7 patients from groups A and B respectively, cleared serum HCV RNA however, only one sustained responder from each group cleared HCV RNA from peripheral blood mononuclear cells. At 18 months, 3 patients remained serum HCV RNA negative. Adverse effects were similar. Only haemoglobin values were lower in group B in the first month of therapy (p<0.05).

CONCLUSION

In conclusion, the combination of 3 MU of interferon plus 600 mg of ribavirin is not effective in chronic hepatitis C resistant to interferon.

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.

Interferon alpha with ribavirin for the treatment of chronic hepatitis C in non-responders or relapsers to interferon monotherapy

BACKGROUND

A more effective therapy for chronic hepatitis C virus-infected patients is needed.

AIM

To evaluate the efficacy, tolerance and timing of response to interferon alpha plus ribavirin in 60 patients with no response or reactivation after interferon alpha alone.

METHODS

Sixty patients, 42 non-responders and 18 relapsers, received 3 million units three times weekly of interferon alpha-2b plus 1-1.2 g ribavirin daily, for 6 months. Basal biochemical and virological (HCV RNA and genotype) parameters were determined. Clinical examination, recording adverse effects, and laboratory tests, including viraemia, were carried out at 1, 2, 3 and 6 months.

RESULTS

A significant (P < 0.001) progressive decrease of HCV RNA and alanine transaminase (ALT) levels was observed during treatment. On finalizing the sixth month, 42 patients (70%) had normal ALT and 26 (43.3%) were HCV RNA negative. Of these 26 complete responders, in 20 the viraemia was undetectable by the third month, while a late clearance at the sixth month of treatment was observed in six patients. Response rates were higher in previous responders to interferon alone (P < 0.05). Mild adverse effects appeared in 46 patients (79.6%), but only three were withdrawn due to serious side-effects. Significantly (P < 0.001), haemoglobin and leucocytes decreased, and bilirubin, ferritin and uric acid increased in the first month of treatment, with no changes thereafter.

CONCLUSIONS

Interferon alpha plus ribavirin progressively decreased HCV RNA and ALT levels, achieving a complete response in the six months of treatment in 26 (43.3%) patients. This combined therapy was well tolerated.

Sequential versus concomitant administration of ribavirin and interferon alfa-n3 in patients with chronic hepatitis C not responding to interferon alone: results of a randomized, controlled trial

We conducted a three-arm, randomized trial in 96 patients with chronic hepatitis C who did not respond to interferon alfa to compare treatments. Group 1 (33 patients) received ribavirin alone (1,000 mg/daily for 6 months) followed by interferon alfa n-3 alone (3 MU thrice weekly for 6 months); group 2 (33 patients) received ribavirin plus interferon alfa n-3 for 6 months at the above doses; and group 3 (30 patients) received interferon alfa n-3 alone (3 MU thrice weekly for 6 months). At the end of treatment, 3 patients (10%) in group 1, 13 (41%) in group 2, and 5 (17%) in group 3 had normal alanine transaminase (ALT) levels (group 2 vs. groups 1 and 3, P = .008). After 6 months of follow-up, only 4 patients (12.5%) in group 2 still had normal ALT values (P = .03). At the end of therapy, hepatitis C virus (HCV) RNA was no longer detectable by polymerase chain reaction in 4 (13%), 9 (27%), and 2 (7%) patients, respectively, in groups 1, 2, and 3 (P = NS). Six months posttherapy, only 5 (15%) patients in group 2 were still HCV RNA negative (P = .02). At the time of follow-up liver biopsy, performed 6 months after the end of treatment, a significant improvement of the necroinflammatory scores was observed among group 2 patients (P = .01) but not in the other two groups. Side effects reflected the profile of each drug as monotherapy; mild hemolytic anemia was the most frequent side effect caused by ribavirin. In conclusion, concomitant administration of ribavirin and interferon alfa n-3 was significantly superior to the sequential schedule or interferon alfa n-3 monotherapy in inducing a sustained response in patients with chronic hepatitis C who had not responded to interferon alone. However, combination therapy at the dose and duration adopted in this study is capable of modifying the natural course of the disease in only a minority of these patients.

Re-treatment with interferon alfa of patients with chronic hepatitis C

Treatment of patients with chronic hepatitis C has had limited success because of relapses and nonresponse to interferon alfa therapy (currently the only established therapeutic agent). A retrospective study was done to determine the efficacy of re-treatment with interferon and the predictors of response in patients who failed to achieve sustained response after one standard course of interferon therapy (3 million units three times a week for 24 weeks). One hundred and eleven patients (47 relapsers and 64 nonresponders), mean age 45 years, were included in the study. Eighteen relapsers and 13 nonresponders received a higher dose (5 MU), and 11 relapsers and 6 nonresponders received a longer duration (48 weeks) of interferon therapy. The remaining patients received the same regimen as the first treatment. Eighty-one percent and 23% of relapsers and nonresponders, respectively, had an end-of-treatment response, and 19% and 3% of the corresponding patient groups had a sustained response to re-treatment. Two patients with breakthrough during their first treatment were the only nonresponders with sustained response after re-treatment. Sustained response was observed only in patients who received an increased dose or duration of interferon therapy. No predictor of sustained response was found. In conclusion, sustained response to re-treatment with interferon was only observed with augmentation of dose or duration of therapy in some relapsers and patients who had breakthrough. Established predictors of response to interferon in naive patients, in particular serum hepatitis C virus RNA and genotype, were not associated with sustained response to re-treatment.

Inhibition of coxsackievirus B3 carrier state infection of cultured human myocardial fibroblasts by ribavirin and human natural interferon-alpha

As enterovirus infections of the heart cause myocarditis and eventually congestive heart failure, the antiviral activity of ribavirin was studied in coxsackie virus B3 (CVB3)-infected carrier cultures of human myocardial fibroblasts. Cultures were infected 7 days before application of ribavirin and effects were evaluated over a period of 16 days by plaque assays and in situ hybridization. Compared to the low antiviral activity in HeLa cells, ribavirin was highly active in reducing infectious virus yields in human myocardial fibroblasts, for example, to 2.0 x 10(3) pfu/ml with 25 microg/ml and to 1.3 x 10(2) pfu/ml with 50 microg/ml (4.3 x 10(4) pfu/ml in infected controls). Moreover, 100 microg ribavirin/ml completely suppressed infectious virus progeny in two of three cultures, and reduced the number of infected cells from 14.3 to 0.3% as determined by in situ hybridization, whereas up to 3200 microg ribavirin/ml did not result in a significant cytotoxic effect. Interaction with interferon-alpha (IFN-alpha) was additive to slightly synergistic in reducing the number of infected cells and virus yields. In conclusion, our results suggest a cell-specific high activity of ribavirin in human myocardial fibroblasts and indicate the importance of using organ-specific cells for testing antiviral agents in myocarditis. Furthermore, the usefulness of in situ hybridization for determining the long term effects of antivirals in carrier state cell cultures was demonstrated.

A randomized controlled trial of high-dose maintenance interferon therapy in chronic hepatitis C

In chronic hepatitis C virus (HCV) infection, the rate of sustained response to interferon is low. We evaluated, in patients responding to a 26-week course of interferon, the effect of high-dose maintenance therapy in preventing relapse. Three hundred and ten patients with chronic HCV infection (38.3% with cirrhosis, 80.6% with HCV type 1) received interferon alfa-2b for 26 weeks (10 MU tiw for 8 weeks, then 5 MU tiw for 18 weeks). One hundred and twenty-four subjects (40%) normalized aminotransferases, and were allocated randomly either to continue on 5 MU tiw for a further 26 weeks (prolonged therapy group: 60 patients) or to stop interferon (brief therapy group: 64 patients). Fifty-two weeks after stopping interferon the overall sustained biochemical response rate was 13.2% (41/310). The number of patients with normal aminotransferases was comparable between the prolonged and brief therapy groups (30% vs. 35.9%, P = n.s.), and the rate of HCV-RNA clearance was similar (48.8% vs. 42.4%, P = n.s.). The timing of posttreatment relapse was not influenced by the duration of therapy. Fifty-nine patients (19%) did not complete therapy due to adverse effects. Multivariate analysis identified four features predicting sustained biochemical response in subjects normalizing aminotransferases under therapy: negative HCV-RNA at end of therapy, normal aminotransferases at 4 weeks of therapy, high baseline aminotransferases, and high baseline platelets. Infection with HCV type 1 was not a significant predictor of response, due to its high prevalence in our population (80.6%). It is concluded that in patients with chronic hepatitis C mostly infected by HCV type 1, a prolonged high-dose interferon course (900 MU over 52 weeks) did not increase the rate of sustained biochemical response and of HCV-RNA clearance in comparison to a brief course (510 MU over 26 weeks).