Re-treatment of chronic hepatitis C with consensus interferon

Design, biological activity and signaling pathway of bovine consensus omega interferon expressed in Pichia pastoris

The bovine IFN-ω (BoIFN-ω) multigene family is located on chromosome 8, which has 14 potential functional genes and 10 pseudogenes. After aligning 14 BoIFN-ω subtypes and assigning the most frequently occurring amino acids in each position, one artificial consensus BoIFN-ω (CoBoIFN-ω) gene was designed, optimized and synthesized. Then, CoBoIFN-ω was expressed in Pichia pastoris, which was demonstrated to have 3.94-fold and 14.3-fold higher antiviral activity against VSV on MDBK cells than that of BoIFN-ω24 and BoIFN-ω3, respectively. Besides this, CoBoIFN-ω was confirmed to have antiviral activity against VSV on BL, BT, PK-15 cells, and against BEV, BHV-1, BPIV3 on MDBK cells. Additionally, CoBoIFN-ω could bind with bovine type I IFN receptors, and then activate the promoters of NF-κB, ISRE and BoIFN-β, and induce the transcription of ISGs and expression of Mx1 and NF-κB p65, which suggested CoBoIFN-ω exerts antiviral activity via activation of the JAK-STAT signaling pathway. Overall, this research on CoBoIFN-ω not only extends and improves consensus IFN research, but also reveals that CoBoIFN-ω has the potential to be used in the therapy of bovine viral diseases.

Consensus interferon plus ribavirin for hepatitis C genotype 3 patients previously treated with pegylated interferon plus ribavirin

BACKGROUND

Not enough data are available about the effectiveness of consensus interferon (CIFN) among HCV genotype 3 patients who failed to respond to pegylated interferon and ribavirin.

OBJECTIVES

We aimed to assess the efficacy and safety of CIFN and ribavirin in non-responders and relapsers to pegylated interferon with ribavirin therapy.

PATIENTS AND METHODS

This open-label investigator-initiated study included 44 patients who received CIFN 15 µg /day plus ribavirin 800-1200 mg daily. In patients with an early virological response (EVR), the dose of CIFN was reduced to 15 µg thrice a week for further 36 weeks. Patients with delayed virological response continued to receive daily CIFN plus ribavirin to complete 48 weeks. The patients were considered "non-responders" if there were less than 2 log reduction in HCV RNA at 12 weeks and detectable HCV RNA at 24 weeks.

RESULTS

Twenty-four patients (55%) were non-responders and 20 patients were relapsers to the previous treatment with pegylated interferon plus ribavirin (mean age 43.6 ± 9.4 years, males 25 (57%)). Nine patients were clinically cirrhotic (Child A). End of treatment virological response was achieved in 19 (43.1%) patients and sustained virological response (SVR) occurred in 12 (27.3%). Out of these 12 patients, eight were non-responders and four were relapsers to the previous treatment. Advanced fibrosis or clinical cirrhosis was associated with low SVR. Adverse events were fever, myalgia, anorexia, depression, and weight loss. Two patients received granulocyte colony stimulating factor for transient neutropenia. Seven patients were given erythropoietin to improve hemoglobin, and six were treated for mild depression. Two patients developed portosystemic encephalopathy.

CONCLUSIONS

More than one-quarter of treatment-experienced patients with HCV genotype 3 achieved SVR after re-treatment with consensus interferon plus ribavirin.

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.

Consensus interferon used to treat prior partial-responders to pegylated interferon plus ribavirin

BACKGROUND

The response to pegylated interferon (peg-IFN) plus ribavirin therapy remains less than ideal with 40-50% of treated subjects failing to clear the virus. Moreover, retreatment is only minimally effective. Consensus interferon (c-IFN) has been shown to be efficacious in HCV genotype 1 patients who have failed therapy with peg-IFN.

AIM

To evaluated the response to re-treatment of peg-IFN plus ribavirin partial-responders with c-IFN plus ribavirin.

METHODS

Forty-two subjects who had previously failed to clear virus after treatment with peg-IFN plus ribavirin were treated with c-IFN (15 μg/day) plus ribavirin (800-1,200 mg/day) until 12 months of therapy or a total of six consecutive months of PCR negativity was achieved.

RESULTS

The study population consisted predominantly of males (71%), Caucasians (76%), with African Americans comprising the remaining 24%, subjects with HCV genotype 1 infection (81%) and 21% had cirrhosis by liver biopsy. The overall SVR rate was 29%. The only pretreatment variable that distinguished responders from partial-responders was the serum triglyceride level.

CONCLUSIONS

The use of c-IFN plus ribavirin in the retreatment of prior peg-IFN plus ribavirin partial responders is essentially twice that achieved in prior re-treatment regimens consisting of a second course of peg-IFN plus ribavirin. These results will need to be evaluated against the use of triple therapy consisting of a peg-IFN plus ribavirin and a protease inhibitor. More studies utilizing c-IFN plus ribavirin with either a protease inhibitor or polymerase inhibitor need to be performed as well.

Interferon combination therapy for HIV/hepatitis C virus coinfection

IFN-α has been the cornerstone of chronic hepatitis C virus (HCV) treatment for over a decade. Yet, rates of sustained virologic response of HCV infection to interferon-based therapy, particularly in difficult-to-treat populations, have been disappointingly low. This is particularly true in HIV/HCV coinfection, in which less than a third of patients typically respond to therapy. New HCV protease inhibitors, most of which will need to be administered with pegylated interferon, are in development, but comprehensive, long-term data for their use in coinfected patients is not yet available. Understanding the basis of this population's poor response to interferon-based therapy is crucial to future exploration of new therapeutic options, immunotherapy and prognosis in HIV/HCV-coinfected population.

Review of consensus interferon in the treatment of chronic hepatitis C

Consensus interferon (CIFN) is an artificially engineered interferon that reflects most of the human genotype 1 interferons and shows a higher biological and antiviral capacity in vitro. It has been used internationally to treat patients with chronic hepatitis C (HCV) infection before pegylated IFN became available. To mimic the half-life of PEG-IFN it has to be administered on a daily basis. The gold standard in the treatment of hepatitis C is well established and recommended. Today patients are being treated with a combination therapy of pegylated IFN and ribavirin. Length and dosage of therapy depends on the genotype of the virus. Patients with genotype 1 and 4 and high viral load should be treated for 48 weeks; for patients with these genotypes along with either low viral load or early virological response, therapy for 24 weeks is sufficient. Patients with genotype 2 and 3 should be treated for up to 24 weeks. However, daily dosing of IFN-α, eg, CIFN, resulting in a higher cumulative dosage, might be beneficial and more efficacious in some chronic HCV-infected patients. Patients with genotype 1, having initially high viral load (>800,000 IU/mL) and showing advanced liver disease with progressive fibrosis or even cirrhosis comprise the difficult-to-treat in order to overcome the infection. This review summarizes and critically discusses the published data on the treatment of HCV with CIFN.

Chronic hepatitis C

The goal of antiviral therapy for patients with chronic hepatitis C virus (HCV) infection is to attain a sustained virologic response (SVR), which is defined as undetectable serum HCV-RNA levels at 6 months after the cessation of treatment. Major improvements in antiviral therapy for chronic hepatitis C have occurred in the past decade. The addition of ribavirin to interferon-alfa therapy and the introduction of pegylated interferon (PEG-IFN) have substantially improved SVR rates in patients with chronic hepatitis C. The optimization of HCV therapy with PEG-IFN and ribavirin continues to evolve. Studies are ongoing that use viral kinetics to tailor therapy to an individual's antiviral response and determine the ideal length of treatment to maximize the chance of SVR. Improved SVR can be achieved with new specific inhibitors that target the HCV NS3/4A protease and the NS5B polymerase. Several long-term follow-up studies have shown that SVR, when achieved, is associated with a very low risk of virologic relapse. Furthermore, antiviral therapy can reduce the morbidity and mortality rates associated with chronic hepatitis C by reducing fibrosis progression, the incidence of cirrhosis, and hepatocellular carcinoma.

Efficacy and cost-effectiveness of consensus interferon monotherapy with high-dose induction for hepatitis C patients with genotype 2

OBJECTIVE

Several treatment strategies for patients with chronic hepatitis C have been compared mainly in terms of their efficacy, and it has been found that pegylated interferon (IFN) plus ribavirin has become the standard therapy, but aged patients may not tolerate ribavirin and the cost-effectiveness of treatment should also be further considered. We conducted a study to evaluate the efficacy, safety, and cost-effectiveness of consensus IFN monotherapy with high-dose induction for patients with chronic hepatitis C in clinical practice.

MATERIAL AND METHODS

We consecutively enrolled 104 patients with chronic hepatitis C. Patients were scheduled to receive 12 or 18 μg of consensus IFN daily for 2 weeks, then three times a week for 22 weeks. Efficacy, safety, and cost-effectiveness were assessed. A Markov model was developed to investigate cost-effectiveness in patients with chronic hepatitis C treated by different IFN-based treatment strategies.

RESULTS

Of the 104 study patients, a sustained virological response (SVR) was achieved in 66 (63%). Logistic regression analysis revealed that genotype 2, lower hepatitis C virus RNA levels, and patient age were independently associated with SVR. The response rate was significantly higher in patients with genotype 2 (51/66, 77%) versus genotype 1 (15/38, 40%). Cost-effectiveness analysis in patients with genotype 2 revealed that high-dose induction with consensus IFN monotherapy was as highly cost-effective as pegylated IFN plus ribavirin.

CONCLUSION

Consensus IFN monotherapy with high-dose induction shows high efficacy and cost-effectiveness in chronic hepatitis C patients with genotype 2 infection. Thus, it may be a reliable alternative in aged patients and for those excluded from standard combination therapy.

Retreatment of patients nonresponsive to pegylated interferon and ribavirin with daily high-dose consensus interferon

Background. Current treatment of chronic hepatitis C with pegylated interferon and ribavirin has the ability to eliminate viral infection in about half of the patients treated. Therapeutic options, for those with remaining chronic hepatitis, will remain limited until novel antivirals become available in the future. Consensus interferon is currently available and has demonstrated clinical efficacy with superior invitro antiviral activity, but the maximum tolerated dose is not defined. Methods. We assessed the efficacy of daily high-dose (24 ug) consensus interferon with weight-based (1000-1200 mg daily) ribavirin in HCV genotype 1-infected non-responder patients. Results. Six adverse events were documented in five patients, and the trial was terminated with no subject achieving viral clearance. Conclusions. The occurrence of serious adverse events effectively defined the upper limit of acceptable dose, while also revealing that this dose did not offer enhanced sustained viral clearance.

Managing pediatric hepatitis C: current and emerging treatment options

Since 1992, the maternal–fetal route of transmission has become the dominant route for acquisition of hepatitis C (HCV) infection by children. With increasing knowledge of antiviral treatment for HCV infection, the main goal of therapy is to achieve a sustained virological response (SVR) as defined by undetectable serum HCV RNA by polymerase chain reaction assay six months after cessation of therapy. In young children, interferon therapy is more effective than in adults with chronic HCV infection (CHC). Although children clearly have a milder degree of liver pathology, data have indicated that hepatic inflammation from HCV infection can progress to fibrosis or cirrhosis in children. Hepatocellular carcinoma has been reported in adolescents with CHC. In this article, recent improvements in therapy of children with CHC and in the clinical development of new emerging drugs with potential use in children will be reviewed.

Elevated hepatic transaminases associated with the use of interferon alfacon-1 and ribavirin

PURPOSE

The case of a patient with hepatitis C who developed elevated hepatic transaminase levels associated with the use of interferon alfacon-1 and ribavirin is described.

SUMMARY

A 55-year-old Caucasian man arrived at a hepatitis C clinic to discuss alternative treatment options for his hepatitis C virus (genotype 1a) infection, which did not respond to a 48-week course of peginterferon and ribavirin therapy. He was subsequently treated with interferon alfacon-1 9 microg subcutaneously daily plus ribavirin 200 mg orally twice daily. During treatment with interferon alfacon-1, he developed elevated hepatic transaminase levels despite a decrease in viral load. His hepatic transaminase levels returned to baseline when interferon alfacon-1 was discontinued and rose again upon rechallenge. Ribavirin was not the likely cause of the increase in transaminases since the patient previously tolerated it in combination with peginterferon. While activation of autoimmune hepatitis is a potential cause of acute decompensation in patients treated with interferons, it was not believed to be the case in this patient. Interferon alfacon-1 was determined to be the probable cause of the rise in hepatic transaminase levels in this patient, since his levels declined when therapy was discontinued and rose dramatically once it was restarted. This case illustrates the importance of monitoring both viral loads and hepatic transaminase levels in patients with hepatitis C being treated with interferon therapy.

CONCLUSION

A patient with hepatitis C developed elevated hepatic transaminase levels despite showing an improvement in viral load after receiving interferon alfacon-1 and ribavirin.

Optimizing the current therapy for chronic hepatitis C virus: peginterferon and ribavirin dosing and the utility of growth factors

Achieving a sustained virologic response depends on the patient achieving three sequential independent milestones: virologic response, maintaining this response throughout treatment, and not relapsing after treatment has been completed. The ability to achieve these milestones depends on the doses of interferon/peginterferon and ribavirin used and on whether treatment with these medications is adjusted, interrupted, or prematurely discontinued in response to adverse events. This review discusses strategies to optimize peginterferon and ribavirin dosing and the impact that growth factors may have on the ability to achieve a sustained virologic response.

Interferon alfacon 1 inhibits SARS-CoV infection in human bronchial epithelial Calu-3 cells

The primary targets for SARS-CoV infection are the epithelial cells in the respiratory and intestinal tract. The angiotensin-converting enzyme 2 (ACE-2) has been identified as a functional receptor for SARS-CoV. ACE-2 has been shown to be expressed at the apical domain of polarized Calu-3 cells. In this report, interferon alfacon 1 was examined for inhibitory activities against SARS-CoV on human lung carcinoma epithelial Calu-3 cell line and the other three African green monkey kidney epithelial cell lines. Interferon alfacon 1 demonstrated significant antiviral activity in neutral red uptake assay and virus yield reduction assay. The data might provide an important insight into the mechanism of pathogenesis of SARS-CoV allowing further development of antiviral therapies for treating SARS infections.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of PEGIFN and RBV is the most effective therapy for patients with chronic hepatitis C. Although more than half of all patients are able to achieve SVR, a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. An approach in the management of these patients is to identify factors that could have led to the NR or relapse and that could be corrected before or during a second course of therapy. Because fibrosis progression occurs slowly over decades for many patients with chronic hepatitis C, avoiding alcohol or other factors that could lead to fibrosis progression may be sufficient for the vast majority of patients. Other options that could be considered in patients who have more advanced disease include retreating with one of several new antiviral agents; retreating with higher doses of IFN or PEGIFN and RBV; or using IFN, PEGIFN, or RBV monotherapy long-term as maintenance therapy. The safety and efficacy of these approaches is being evaluated in numerous clinical trials.

Old and emerging therapies in chronic hepatitis C: an update

The main goal of therapy in hepatitis C virus (HCV) infection is to achieve a sustained virological response currently defined as undetectable HCV-RNA in peripheral blood determined with the most sensitive polymerase chain reaction technique 24 weeks after the end of treatment. This goal is practically equivalent with eradication of HCV infection and cure of the underlying HCV-induced liver disease. The current standard in hepatitis C treatment consists in combination regimens of pegylated interferon-alpha (Peg-INF-alpha) with Ribavirin (RBV). Such treatment schemes are quite successful in patients with HCV genotypes 2 and 3 infections achieving HCV eradication rates of 75-90%. However, they are much less effective in patients with genotypes 1 and 4 infections with eradication rates ranging between 45% and 52%. Moreover, they have several, and sometimes severe, adverse effects and contraindications, further limiting their efficacy and applicability in an appreciable number of patients with chronic HCV-induced liver disease. Therefore, the need for improvement of existing therapies and for development of new effective, safe and tolerable drugs is a matter of great clinical relevance and importance. In this article, recent improvements in the current standard of therapy with IFN-alpha and RBV in various subsets of patients with chronic hepatitis C and in the clinical development of new emerging drugs, particularly small molecules, will be reviewed and commented. The article is divided in two main parts: (i) improvements in the standard combination therapies and schemes of approved Peg-INF-alpha with RBV and expectations from new interferons, interferon inducers and alternatives to RBV; (ii) new drugs for HCV in clinical development focusing mostly on specific inhibitors of HCV and less so on other drugs including immune therapies.

Retreatment of chronic hepatitis C in previous non-responders and relapsers

Therapy for chronic hepatitis C has improved dramatically over the past 20 years. Unfortunately, approximately 50% of those treated do not have a durable response to therapy. Non-responders and relapsers after previous interferon-based therapy are particularly challenging with regard to clinical management. This article provides a general overview of the treatment of hepatitis C and reviews present data regarding management of patients with chronic hepatitis C who are non-responders or relapsers after previous treatment. The review ends with the authors' opinion regarding present management of non-responders and relapsers and future emerging therapies.

Different doses of consensus interferon plus ribavirin in patients with hepatitis C virus genotype 1 relapsed after interferon monotherapy: A randomized controlled trial

AIM: To assess the efficacy of different schedules of consensus interferon (CIFN) plus ribavirin in retreating chronic hepatitis C patients who relapsed after recombinant interferon (rIFN) monotherapy.

METHODS: Forty-five patients (34 males and 11 females) with chronic hepatitis due to hepatitis C virus (HCV) genotype 1 who relapsed after a previous course of rIFN monotherapy were randomized to receive 9 μg CIFN three times per week for 52 wk (group A, n = 22) or 18 μg CIFN three times per week for 52 wk (group B, n = 23) in combination with ribavirin 800 to 1200 mg daily for 52 wk (according to body weight). Virological response was evaluated at week 24 (EVR), at the end of treatment (ETR) and at 76 wk (SVR).

RESULTS: By intention-to-treat analysis, subjects in group A had an EVR in 35% of cases, an ETR in 35% and a SVR in 27.3% of cases. Subjects in group B had an EVR in 32% of cases, an ETR in 35% and a SVR in 26.1% of cases. Treatment was stopped because of adverse effects (mostly intolerance) in 15 patients (6 in group A and 9 in group B). IFN dose reduction was needed in 2 patients (1 in group A and 1 in group B). Ribavirin dose was reduced in 2 patients in group A and 1 in group B respectively. Among the 15 subjects who received at least 80% of the intended schedule, the rate of SVR was 80% (6 in group A and 6 in group B).

CONCLUSION: CIFN in combination with ribavirin when given to HCV genotype 1 relapsers after rIFN monotherapy obtains an unsatisfactory rate of sustained viral clearance independently of dosage of the drug. This may be due to its scarce tolerability.

Optimizing Treatment Outcomes in Chronic Hepatitis C: Management of Non-Response

The overarching goal in treating chronic hepatitis C (CHC) is the prevention of serious hepatic complications such as cirrhosis, end-stage liver disease and hepatocellular carcinoma. Successful eradication of the hepatitis C virus has been shown to prevent liver disease progression and even promote regression of fibrosis. The treatment of CHC has improved significantly over the past decade with the introduction of interferons (IFNs), and more recently, pegylated IFNs. Up to two-thirds of all patients treated with a pegylated IFN combined with ribavirin can now achieve viral eradication if treated according to current guidelines. Despite this success rate, limited treatment options currently exist for the growing number of patients who do not respond to this combination, and those who have previously failed treatment with conventional IFN-based regimens. There are numerous host-and viral-related factors that can contribute to these outcomes. In addition, treatment insufficiency, whether due to treatment type, side effects or non-compliance, can result in inadequate antiviral pressure and a reduced likelihood of response. This review explores putative management strategies for patients who have previously failed to achieve a response to IFN-based therapy, and summarises retreatment options that have been, and are currently being evaluated.

Consensus interferon and ribavirin for patients with chronic hepatitis C and failure of previous interferon-alpha therapy

BACKGROUND

The efficacy of consensus interferon (CIFN), a synthetic IFN with optimised in vitro activity, was assessed in chronic hepatitis C virus (HCV) patients who had failed the pretreatment with interferon-alpha (IFNalpha) and ribavirin.

METHODS

One hundred and three patients after non-response (n=69) or relapse (n=34) to IFNalpha+/-ribavirin were randomly assigned to high-dose induction (CIFN 27-->9 microg daily for 24 weeks, 9 microg t.i.w. for 24 weeks) or low-dose treatment (CIFN 18 microg t.i.w. for 12 weeks, 9 microg t.i.w. for 36 weeks); each with ribavirin 800 mg/day. Follow-up was 24 weeks.

RESULTS

Non-responder patients treated with high-dose induction had higher early virological response rates (63% vs. 39%, P<0.05). This initial positive effect was lost during the last 24 weeks of treatment yielding sustained virological response (SVR) rates of 26% in both groups. Relapse patients revealed SVR in 70% and 38% in groups A and B (NS). Treatment was well tolerated with side effect-related preterm discontinuations in 8% and 5%.

CONCLUSIONS

CIFN and ribavirin treatment induced considerable SVR rates in patients with non-response or relapse to IFNalpha+/-ribavirin. Viral elimination rates might be further increased by continuous daily administration of CIFN and weight-adjusted ribavirin dosing.

Chronic hepatitis C: treatment of pegylated interferon/ribavirin nonresponders

Patients with chronic hepatitis C virus (HCV) who were nonresponders to previous treatment with pegylated interferon and ribavirin are a growing population. The vast majority have genotype 1, a high viral load, advanced fibrosis or cirrhosis, and are of African-American race. The evaluation of these patients should include a thorough review of the previous treatment record and characterization of the previous nonresponse. Patients with prior null response are likely resistant to the effects of interferon. In contrast, patients with partial virologic response, breakthrough, and relapse could potentially achieve sustained virologic response if one or more correctable factors that contributed to the prior nonresponse are identified and addressed before and during retreatment. Many HCV nonresponders, especially those with no fibrosis or mild fibrosis, have an excellent prognosis, are at low risk to develop cirrhosis, and should simply be monitored at periodic intervals until more effective therapy has been developed.

Treatment with daily consensus interferon (CIFN) plus ribavirin in non-responder patients with chronic hepatitis C: a randomized open-label pilot study

BACKGROUND/AIMS

Therapeutic options for hepatitis C non-responder patients are limited.

METHODS

We initiated an open-label pilot study to investigate the efficacy of CIFN plus ribavirin on viral kinetics, sustained virological response (SVR), and histological response in hepatitis C non-responder patients. Seventy-seven patients were enrolled to receive CIFN given daily in combination with 1000/1200 mg ribavirin. An 8-week induction-dosing regimen of 18 microg CIFN, followed by 9 microg for 40 weeks was compared to 9 microg CIFN for 48 weeks. 90% of patients were infected with HCV-genotype 1.

RESULTS

Overall, 82% of the patients demonstrated an early virological response, 65% had an end-of-treatment response, and the SVR was 30%. Interferon/ribavirin non-responders demonstrated a SVR of 22%. Induction-dosing resulted in a greater first-phase HCV-RNA decay that, however, did not translate to better SVRs, presumably due to more dose modifications. High ALT, younger age, and second-phase viral kinetics were associated with SVR. Only sustained responders and relapse patients showed an improved liver histology.

CONCLUSIONS

Daily dosing of CIFN plus ribavirin may be a promising concept for selected non-responder patients before considering therapies which are anti-viral but not curative. However, motivation and compliance are requisites and a CIFN induction is not required.

Induction therapy with twice-daily interferon-beta does not improve the therapeutic efficacy of consensus interferon monotherapy for chronic hepatitis C

We examined therapeutic superiority of induction therapy with twice-daily IFN-beta (3X2=6 million units/day) onto 6-months consensus interferon monotherapy for chronic hepatitis C. Patients were randomly assigned to monotherapy without (group I, n=16) and with induction therapy (group II, n=12). The mean age of group II was older than that of group I, and other baseline condition was not statistically significant. Sustained virological response (SVR) rates of group I and II were 81.3% (13/16) and 58.3% (7/12), respectively (p=0.365). SVR rates in patients with genotype 1b were 66.7% (4/6) and 0% (0/2, because of drop-out), and those with high viral load were 70% (7/10) and 75% (6/8) in group I and II, respectively (p=1.000). Drop-out rates during therapy were 6.3% (1/16) and 33.3% (4/12) in group I and II, respectively (p=0.176). Age less than 50 years was the only independent factor that was shown by multivariate logistic model analysis to be associated with a sustained virological response. Although randomization failed to produce and equal age distribution in the two groups in this study, our results suggest that induction therapy with twice-daily IFN-beta has no beneficial effect on the efficacy of monotherapy with consensus interferon, probably because of the higher drop-out rates and incidence of adverse reactions with induction therapy.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of peginterferon and ribavirin is the most effective therapy for patients with chronic hepatitis C virus (HCV) infection. Although more than half of all patients are able to achieve a sustained virologic response (SVR), a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. The management of these patients creates a formidable challenge. This article outlines various strategies for patients who have failed to achieve SVR and discusses the merits of different approaches to management.

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Efficacy and Safety of Intravenous Iron Therapy for HCV-Positive Haemodialysis Patients

BACKGROUND

Iron supplementation is the cornerstone of anaemia management in haemodialysis (HD) patients. However, efficacy and safety of intravenous (IV) iron therapy in hepatitis C virus (HCV)-positive HD patients is yet to be elucidated.

METHODS

Sixty-six maintenance HD patients with suboptimal response to recombinant human erythropoietin (rh-EPO) were administered IV iron. Each patient received 100 mg/session IV iron sucrose for ten consecutive HD sessions and then the dose was decreased to 50-100 mg weekly or biweekly. Patients were followed for haemoglobin (Hb), ferritin, rh-EPO dose requirements, transaminase levels, and adverse drug reactions.

RESULTS

Baseline demographic and clinical characteristics, as well as Hb, ferritin, transaminase levels, rh-EPO and iron doses were similar between HCV-positive (n = 32) and HCV-negative patients (n = 29). After 5 months of follow-up, a significant increase in ferritin and Hb levels and decrease in rh-EPO doses were observed in both groups. The incidence of adverse drug reactions was not associated with HCV serology. Significant elevation in both alanine and aspartate aminotransferase levels were detected in HCV-positive patients.

CONCLUSION

This study has shown that IV iron administration reverses suboptimal response to rh-EPO administration in HD patients regardless of HCV serology. There is however subtle increase of transaminase levels in HCV-positive patients. Further studies are warranted to reveal the impact of variation in serum transaminase levels during IV iron administration in HCV-positive HD patients.

[Therapy of acute hepatitis C infection]

BACKGROUND

Hepatitis C viral infection is a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. The progression of acute to chronic infection occurs in 50-90% of cases. There is no standard therapy for acute HCV infection. Comparative studies are required to verify the optimal doses, dosage schedules and the treatment duration, and to establish the optimal treatment for acute hepatitis C. Recent reports have demonstrated that early application of interferon alpha was a treatment of choice for acute HCV infection. The addition of ribavirinin in the treatment of acute HCV infection, and HCV genotype, did not improve the end-of-treatment responses. It is important to consider the treatment of acute HCV infection before it progresses to chronic state.

CASE REPORT

Beneficial effect of interferon therapy in a patient with acute hepatitis C is presented. Early treatment with 3 MIU interferon alpha, three times a week, within six-months, resulted in the normal serum aminotransferases, and good virological response in our patient.

CONCLUSION

Interferon therapy significantly increased the probability of obtaining normal serum aminotransferases and undetectable HCV RNA, following acute HCV infection.

Leucoytapheresis with Adacolumn® enhances HCV-specific proliferative responses in patients infected with hepatitis C virus genotype 1

The most important aim in controlling virus infections is to destroy infected cells. Impaired cellular immunity in HIV and HCV infection leads to chronic infection. This study examined the effect of cytapheresis on the subsequent response to interferon/ribavirin treatment in patients infected with HCV. Adacolumn cytapheresis was carried out once a day for 5 consecutive days in patients who relapsed or did not respond to previous peginterferon and ribavirin combination treatment (n = 14: relapsers = 3, non-responders = 11). Peginterferon and ribavirin combination treatment was started after cytapheresis. During combination treatment, the proliferative response of peripheral blood mononuclear cells to HCV proteins (core, NS3, NS4, and NS5), tetanus toxoid, and phytohemagglutinin was measured, and compared to the early virological response. After treatment by leucocytapheresis, the proliferative response of peripheral blood mononuclear cells to HCV-core and tetanus toxoid increased significantly over the baseline (P < 0.05). A marked increase in the phytohemagglutinin response was observed after peginterferon and ribavirin combination treatment was started (P < 0.01 at week 5 and P < 0.005 at week 13). There were, however, no clear changes in the proliferative response to other antigens. Among the 14 patients, 12 (85.7%) achieved an early virological response by week 13 (12 weeks after the start of combination treatment). After treatment, nine patients (64.3%) had a significant proliferative response to HCV core antigen. Among the nine patients, eight patients (88.9%) achieved early virological response. The results indicate that activation of cellular immunity by leucocytapheresis facilitates an early virological response rate in HCV patients. This new therapy may, therefore, become an additional therapeutic measure for HCV.

Chronic hepatitis C and no response to antiviral therapy: potential current and future therapeutic options

A significant proportion of chronic hepatitis C patients fails to achieve sustained virologic response even after treatment with the current, more potent, combination of pegylated interferon-alpha (IFNa) plus ribavirin. Such patients represent a rather heterogeneous group and may be divided initially into relapsers and nonresponders. Both the type of previous therapy and of previous response are very important factors for the indication and the type of re-treatment. The combination of pegylated IFNa and ribavirin seems to be a rational approach for patients who failed to respond to IFNa monotherapy. Pegylated IFNa-based regimens appear to induce sustained responses in 40-68% of relapsers but in only 11% of nonresponders to previous therapy with standard IFNa plus ribavirin. Thus, new therapeutic approaches are needed for the latter subgroup of patients as well as those who fail to respond to pegylated IFNa-based regimens. Such new approaches currently under evaluation include the triple combination of pegylated IFNa, ribavirin, and amantadine, alternative types of IFN, use of agents with ribavirin like activity but lesser degrees of side-effects, inhibitors of hepatitis C virus (HCV) replication, mainly inhibitors of NS3 protease or helicase, antisense oligonucleotides, and ribozymes, and several immunomodulators. Moreover, maintenance antifibrotic therapy, mostly with low doses of pegylated IFNa, are under evaluation in patients with advanced fibrosis. Thus, even in the current era of the potent pegylated IFNa-based regimens, the management of these difficult-to-treat patients represents an increasingly frequent problem and perhaps the most challenging therapeutic task in chronic hepatitis C.

A randomized trial of consensus interferon in combination with ribavirin as initial treatment for chronic hepatitis C

BACKGROUND/AIMS

The aim of the present, open-labeled, randomized study was to determine the efficacy and safety of different doses of consensus interferon plus ribavirin in the initial treatment of chronic hepatitis C.

METHODS

One hundred and one genotype 2/3 patients were randomized to receive 9 mcg (group A, n=48) or 18 mcg (group B, n=53) of consensus interferon thrice weekly plus ribavirin (1000/1200 mg/daily) for 24 weeks and 92 genotype 1 patients to receive 9 mcg (group C, n=47) or 18 mcg (group D, n=45) of consensus interferon plus ribavirin for 48 weeks.

RESULTS

In an intention-to-treat analysis, the sustained virologic response at 24-week follow-up was 69% and 66% for group A and B (P=0.77) and 40% and 36% for group C and D (P=0.63). The overall sustained response was 67% and 38% in patients with genotype 2/3 and 1, respectively. Among genotype 1 patients the sustained virologic response was 39% and 41% for high or low baseline viremia levels.

CONCLUSIONS

Higher consensus interferon dose does not increase sustained virologic response. Naive genotype 1 patients may achieve significant response rate of approximately 40% if treated with 9 mcg of consensus interferon plus ribavirin for 48 weeks.

Comparison of three commercially available assays for HCV RNA using the international unit standard: implications for management of patients with chronic hepatitis C virus infection in clinical practice

OBJECTIVES

The present study was performed to evaluate the impact of the international unit standard for measuring HCV RNA in the management of patients with chronic hepatitis C virus (HCV) infection.

METHODS

The three assays used were Amplicor Monitor PCR, the National Genetics Institute PCR assay, and branched chain DNA. HCV RNA was measured at four time points (baseline, 3 months after the start of therapy, at the end of treatment, and 6 months after discontinuation of therapy) in 106 consecutive patients who received interferon and ribavirin for chronic HCV.

RESULTS

The mean age of the patients was 44 yr. Of the patients, 62% were male, 24% were African American, 38% had bridging fibrosis or cirrhosis, and 75% were HCV genotype 1. Of the 424 samples analyzed, 82-89% of values were within 1 log unit and 85-92% were within 2 log units by the various assays. This variability was not dependent upon HCV genotype. HCV RNA was undetectable in 1.4-6.8% of samples when virus was detected by another assay. The mean HCV RNA in these discordant samples was 1.47-6.33 log IU/ml (30-2,100,000 IU/ml).

CONCLUSIONS

These data demonstrate that approximately 90% of serum values for HCV RNA were within 1 log unit by the international unit standard regardless of which virological assay was used. However, false positive and false negative results as well as variations in the HCV RNA level of more than 1 to 2 log units can occur with any of the assays, and these results may have an impact upon the management of patients receiving interferon therapy. It is therefore unwise in clinical practice to base important treatment decisions upon a single HCV RNA determination.

Efficacy of prolonged 5 million units of interferon in combination with ribavirin for relapser patients with chronic hepatitis C

summary. Retreatment of relapser patients with chronic hepatitis C with the standard dose of interferon (IFN) of 3 million units (MU) thrice weekly (tiw) plus ribavirin for 24 weeks achieves a sustained response in 30 and 73% of patients with genotype 1 and 2 or 3, respectively. The aim of this study was to evaluate the efficacy and safety of IFN alpha-2b induction therapy, followed by prolonged treatment with a high dose of IFN alpha-2b plus ribavirin in relapser patients. A total of 119 patients were randomized to receive IFN alpha-2b 5 MU daily (Group A: 59 patients) or IFN alpha-2b 5 MU tiw (Group B: 60 patients) for 4 weeks followed by IFN (5 MU tiw) and ribavirin (1000-1200 mg/day) for 48 weeks in both groups. The primary end point was hepatitis C virus (HCV)-RNA clearance at week 24 after the end of treatment. A sustained virological response (SVR) was achieved in 68 and 60% of Group A and B patients, respectively (P = 0.37). Logistic regression analysis identified genotype 2 or 3 as the only independent factor associated with response, whereas induction regimen and baseline viraemia levels did not affect the response. The overall SVR was 53 and 72% in patients with genotype 1 or 4 and 2 or 3, respectively. In conclusion, induction IFN therapy does not enhance the SVR to a 48-week combination therapy. Our study suggests that relapsed patients with genotype 1 or 4 may achieve significant response rates of approximately 50%, if retreated with 5 MU tiw IFN plus ribavirin for 48 weeks.

Treatment of chronic hepatitis C in nonresponders to previous therapy

About 55% to 60% of treatment-naïve patients fail to achieve a sustained virologic response after therapy with standard interferon and ribavirin. The use of polyethylene glycol-enhanced interferon (PEG-IFN) plus ribavirin for retreatment of this challenging group is currently being evaluated by several investigators. Although no sustained virologic response rates have been reported yet from these trials, reported on-treatment response rates for previous nonresponders range from 25% to 30%, and an early estimate of the sustained virologic response rate is about 11%. Outcomes for treatment of relapsers and interferon monotherapy nonresponders have been significantly better than those for combination nonresponders. On-treatment responses of 40% to 43% in previous combination therapy nonresponders are now being seen with the addition of amantadine (triple therapy), and sustained response rates with this regimen are awaited. Large trials are underway to evaluate the role of maintenance therapy for virologic nonresponders with advanced liver disease.

Synergistic antiviral effect of a combination of mouse interferon-alpha and interferon-gamma on mouse hepatitis virus

Although interferon (IFN)-alpha and IFN-gamma have been reported to exhibit a synergistic antiviral effect through the different signaling pathways in vitro, their therapeutic efficacy is not well defined in vivo. The current study was carried out to investigate the combined antiviral effect in a model of mouse hepatitis virus Type 2 (MHV-2) infection, in which fulminant hepatitis is developed. MHV-2 was injected intraperitoneally into 4-week-old ICR mice, IFN or the vehicle was administered intramuscularly for 5 days, and the antiviral effect was evaluated based on survival periods, liver histology, serum alanine transaminase (ALT) levels, and MHV-2 virus titers in the liver tissues. The animals in the group treated with a combination of IFN-alpha and IFN-gamma survived for longer periods than the groups treated with IFN-alpha alone and IFN-gamma alone (IFN-alpha 10(3) (IU/mouse)/-gamma 10(3) vs. IFN-alpha 10(3), P < 0.005; IFN-alpha 10(3)/-gamma 10(3) vs. IFN-gamma 10(3), P < 0.001). This is consistent with the lower levels of hepatocellular necrosis and serum ALT and the decreased titers of MHV-2 virus in the liver tissues (48 hr, P < 0.001; 72 hr, P < 0.001). These findings indicate that a combination of IFN-alpha and IFN-gamma exhibits a synergistic antiviral effect on MHV-2 infection. The biology of MHV-2 is quite different from that of human hepatitis viruses; however, these results suggest the beneficial combined therapy of IFN-alpha and IFN-gamma for the treatment of human viral hepatitis.

First phase hepatitis c viral kinetics in previous nonresponders patients

A large proportion of patients fails to respond to treatment for hepatitis C. Initiation of interferon therapy is associated with a rapid first phase decline in viremia, reflecting inhibition of viral production or release from infected cells. We characterized first phase viral kinetics in previous nonresponder patients and compared the antiviral efficacy of interferon in nonresponders to that observed in naive patients. Twenty nonresponders with genotype 1 infection were evaluated. Ten received a single 15 mcg dose of interferon alfacon-1 and ten were given a 30 mcg dose. Viral kinetic data from previously untreated historical control patients with genotype 1 infection who received 9 mcg (n = 12) or 15 mcg (n = 13) of interferon alfacon-1 provided a basis for comparison. Antiviral efficacy was evaluated by calculating the reduction in HCV RNA levels during the first 24 h after interferon administration (log effectiveness). Hepatitis C virus levels decreased exponentially in previous nonresponder patients. Non-responders treated with 30 mcg of interferon alfacon-1 exhibited a greater log drop than non-responders receiving 15 mcg (P = 0.01). The log effectiveness of 15 mcg of interferon alfacon-1 in nonresponders was similar to 9 mcg in naives and was significantly < 15 mcg (P = 0.04) in naïve patients. The 30 mcg dose provided similar log effectiveness in nonresponders compared with 15 mcg in naive patients and exceeded the log effectiveness of 9 mcg in previously untreated patients (P = 0.035). Nonresponders who had greater than a 50% decrease in HCV RNA level from baseline at the end of previous treatment had a larger reduction in viral load at 24 h compared with those who had not achieved that level of response with prior therapy (P = 0.04). In conclusion, the log effectiveness of interferon was lower in nonresponders compared with treatment naive patients. The difference in antiviral effectiveness in previous nonresponders was overcome by higher interferon doses.

[Interferon alfacon-1 (Advaferon): a novel synthetic interferon for the treatment of hepatitis C, its pharmacological and clinical profile]

Interferon alfacon-1 (Advaferon, also referred to as consensus interferon) is a novel synthetic recombinant type-I interferon (IFN) developed by comparing the amino acid sequences of several natural IFN-alpha subtypes and assigning the most frequently observed amino acid in each corresponding position to generate a consensus molecule. Interferon alfacon-1 binds with high affinity to type-I IFN receptors and has greater biological activity than naturally occurring IFN-alpha as assessed by its increased antiviral, anti-proliferative, and natural killer cell activities, as well as its stronger IFN-stimulated gene induction. In a multicenter, randomized, controlled study, the safety and efficacy of interferon alfacon-1 in comparison with lymphoblastoid interferon-alpha [IFN-alpha (NAMALWA)] was evaluated in patients infected with high-titer chronic hepatitis C virus (HCV). Interferon alfacon-1 (18 MIU) was superior in efficacy without additional toxicity to IFN-alpha (NAMALWA) (9 MIU) in high-titer chronic HCV patients, particularly those infected with genotype 1b. A multicenter open-label study showed that treatment with interferon alfacon-1 (12 MIU) was an effective and tolerable therapy in chronic HCV patients with low viral titers. Another multicenter open-label study showed that re-treatment with interferon alfacon-1 (18 MIU) was an effective and tolerable therapy in chronic HCV patients who relapsed after traditional IFN therapy. Collectively, these clinical studies indicate that interferon alfacon-1, as a novel synthetic interferon, may be a useful therapeutic alternative for the effective treatment of hepatitis C.

A randomized 4-arm multicenter study of interferon alfa-2b plus ribavirin in the treatment of patients with chronic hepatitis C relapsing after interferon monotherapy

To determine whether a higher dosage of interferon (IFN) and/or a prolonged time of administration may improve the efficacy of combination therapy, we conducted a 4-arm randomized trial on patients with chronic hepatitis C relapsing after 1 or more previous treatment courses with IFN monotherapy. Group A (n = 70) received 3 MU IFN alfa-2b 3 times per week plus ribavirin 1,000 mg/d for 12 months; group B (n = 70) received 5 MU 3 times per week plus ribavirin for 12 months; group C (n = 82) received 3 MU 3 times per week plus ribavirin for 6 months, and group D (n = 73) received 5 MU 3 times per week plus ribavirin for 6 months. The primary end point was the clearance of viremia at the end of 6-month follow-up: test results for hepatitis C virus (HCV)-RNA were negative in 54% of group A, 56% of group B, 40% of group C, and 49% of group D patients (P = NS). Among patients with genotype 1 and 4, the sustained response was significantly higher in groups A and B than in group C (45%, 49% vs. 22%, P =.03; group D = 33%, P = NS). In patients with genotype 2 and 3, the sustained virologic response was not affected by the different regimens (group A = 69%, group B = 68%, group C = 62%, group D = 71%, P = NS). In conclusion, duration of therapy rather than IFN dosage is more important in increasing the sustained virologic rate among HCV-positive patients with genotype 1 and 4 relapsing after IFN monotherapy; patients with genotypes 2 and 3 can be effectively retreated with a 6-month course of combination therapy, avoiding unnecessary side effects and waste of resources.

Consensus interferon for chronic hepatitis C patients with genotype 1 who failed to respond to, or relapsed after, interferon alpha-2b and ribavirin in combination: an Italian pilot study

OBJECTIVE

To evaluate the long-term efficacy of consensus interferon in the treatment of chronic hepatitis C patients with genotype 1 who failed to respond to, or relapsed after, combination therapy with interferon alpha-2b and ribavirin.

DESIGN

Open label pilot study.

METHODS

Twenty-four chronic hepatitis C outpatient non-responders to (12 cases), or relapsers after (12 cases), standard combination therapy were treated with consensus interferon (9 microg five times per week) for 36 weeks. The patients were followed up for a further 24 weeks. The primary end-point of the study was the rate of sustained virological response.

RESULTS

Sustained virological response was observed in 33% of previous non-responders and in 42% of previous relapsers. Improvement of the histological score was documented in 80% of previous non-responders and in all previous relapsers who showed undetectable levels of hepatitis C virus RNA at the end of treatment. Logistic regression analysis showed that sustained virological response was associated with a hepatitis C viral load of 2 x 106 copies/ml or less, with an inflammation score of 7 or less and with an estimated duration of disease of 10 years or less. The treatment was well tolerated with an 83% compliance.

CONCLUSIONS

Consensus interferon given at a dose of 9 microg five times per week for 36 weeks may offer a good chance of sustained virological response in a subset of patients who failed to respond to, or relapsed after, standard combination therapy. However, a larger randomized trial is required to assess the efficacy of consensus interferon before its use can be advocated for the treatment of such patients.

A randomized trial of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon

BACKGROUND

Conventional interferon monotherapy fails to achieve virological clearance in most hepatitis C-infected patients. The use of high-dose induction regimens may improve the initial clearance of virus, while the addition of ribavirin appears to improve the rates of sustained response once clearance is achieved.

AIM

To compare the efficacy and safety of re-treatment with an induction regimen of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon monotherapy.

METHODS

Previous virological non-responders to standard dose interferon (3-5 MU three times weekly for > or = 12 weeks) were randomized to receive, unblind, either 10 MU interferon alpha-2b daily for 10 days, then 5 MU daily for 74 days, then 5 MU three times weekly for 24 weeks (total 36 weeks) (group A), or the above regimen with the addition of ribavirin, 1000-1200 mg/day, at day 11 (group B). All patients were followed up for 24 weeks after completion of therapy.

RESULTS

End of treatment virological response was noted in one of 10 (10%) patients in group A and in eight of 15 (54%) patients in group B (P=0.04). The sole end treatment responder in group A and three in group B relapsed on follow-up. The apparent improvement in response in group B compared to group A nearly reached statistical significance (group B 5/15 vs. group A 0/10; P=0.06).

CONCLUSIONS

In this small pilot study, a 36-week high-dose induction interferon monotherapy protocol did not yield sustained responses in previous non-responders to standard dose interferon. However, the same regimen with ribavirin yielded a 33% sustained response rate, nearly reaching statistical significance. The therapy was well tolerated, despite the higher doses of interferon used and the addition of ribavirin. High-dose interferon with ribavirin appears to be a therapeutic option for non-responders to conventional interferon monotherapy.

Interferon alfacon-1: a review of its pharmacology and therapeutic efficacy in the treatment of chronic hepatitis C

Interferon alfacon-1 (consensus interferon) is a non-naturally occurring, synthetic, type 1 interferon (IFN)alpha that is used for the treatment of patients with chronic hepatitis C. The efficacy of subcutaneously administered interferon alfacon-1 has been demonstrated in clinical trials during the treatment of LFN-naive patients (interferon alfacon-1 9microg 3 times a week for 24 weeks) and retreatment of nonresponders and relapsers to previous interferon therapy (interferon alfacon1 15 microg 3 times a week for up to 48 weeks). Higher and more frequent interferon alfacon-1 dosages have also been investigated. Results from a pivotal double-blind randomised trial in 704 patients with chronic hepatitis C showed that interferon alfacon-19 microg 3 times a week achieved virological and biochemical response rates of 34.9 and 42.2%, respectively, at treatment end-point (week 24). Sustained virological and biochemical responses (week 48) were reported in 12.1 and 20.3% of the patients, respectively. In general, response rates in recipients of interferon alfacon-1 9 microg 3 times a week were similar to those achieved with IFN-alpha2b 3 MIU 3 times a week. However, interferon alfacon-1 was more effective in the subgroup of patients infected with hepatitis C virus (HCV) genotype 1 at end-point (virological response, 24 vs 15%; p < 0.05) and post-treatment observation period (8 vs 4%) although the difference between treatment groups was statistically significant only at treatment end-point. The sustained virological response rate achieved in patients with high baseline levels of serum HCV RNA receiving interferon alfacon-1 was statistically superior to that exhibited in the IFN-alpha2b treatment group (7 vs 0%; p < Interferon alfacon-1 also showed efficacy during the retreatment of non-responders and relapsers to previous IFN therapy in a large nonblind multicentre trial. Sustained virological response (week 72) was observed among 13 and 58% of nonresponders and relapsers, respectively, after 48 weeks of treatment with interferon alfacon-1 15 microg 3 times a week. Interferon alfacon-1 has been generally well tolerated in clinical trials. As with other IFNs, adverse events were reported frequently but were usually considered of mild to moderate severity, decreased with time and caused a small percentage of patients to withdraw from the treatment. Fever, fatigue, arthralgia, myalgia, headache and rigors were the most frequently reported adverse events. Psychiatric adverse events appeared to be dose-related and caused the majority of treatment withdrawals.

CONCLUSION

Interferon alfacon-1 is generally well tolerated and is an effective agent in the treatment of patients with chronic hepatitis C. Comparative data from a pivotal randomised trial indicate that the drug has at least equivalent efficacy to IFNalpha-2b, and a statistically significant advantage was demonstrated at treatment end-point in patients infected with HCV genotype 1. A number of ongoing trials with interferon alfacon-1 are evaluating issues such as the optimal dosage regimen and duration of therapy in an effort to improve sustained virological response to therapy, a goal for IFNs in general.

Interferon for interferon naive patients with chronic hepatitis C

BACKGROUND

A previous meta-analysis of interferon therapy in naive patients with chronic hepatitis C has documented its efficacy in achieving virologic clearance, and improving liver biochemistry and histology; however, since its publication additional trials have been reported.

OBJECTIVES

To evaluate the response to interferon in interferon naive patients with chronic hepatitis C. The effect of treatment dose and duration, and the response in patients with cirrhosis and those with normal aminotransferases was also investigated.

SEARCH STRATEGY

The Cochrane Controlled Trials Register (Cochrane Library Issue 1, 1999), MEDLINE (January 1966 to December 1999), and reference lists were searched, and pharmaceutical companies were contacted for unpublished trials.

SELECTION CRITERIA

Randomised clinical trials comparing interferon with placebo, no treatment, or different regimens of interferon were selected. Abstracts were excluded.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was sustained disappearance of serum HCV RNA (virologic sustained response (SR)). Biochemical and end of treatment responses, liver histology, and adverse events were also recorded. Assessment of drug efficacy used the methods of Peto and Der Simonian and Laird.

MAIN RESULTS

Fifty-four trials enrolling 6545 patients were included. Compared with no treatment, interferon 3 MU thrice weekly for 12 months increased the probability of a virologic SR (Peto odds ratio (OR) 4.60; 95% confidence interval (CI) 1.53 to 13.85). At this dosage and duration of therapy, the rate of virologic SR was 17% (95% CI 10 to 28%) in interferon-treated patients versus 3% (95% CI 1 to 10%) in controls. A dose of 6 MU was more effective than 3 MU thrice weekly (OR for 12 months treatment, 2.21; 95% CI 1.10 to 4.45), as were durations of 12 months or greater versus six months (OR 1.87; 95% CI 1.30 to 2.67). Adverse events were more common with higher doses and prolonged durations of treatment. Compared with no therapy, interferon increased the probability of histologic improvement (OR 9.22; 95% CI 5.69 to 14.94). The response to interferon in cirrhotic patients (virologic SR, 17%; 95% CI 11 to 26%) was similar to that in non-cirrhotic patients. However, interferon was no more effective than control in patients with normal aminotransferases.

REVIEWER'S CONCLUSIONS

Interferon is effective in achieving viral clearance and improving liver biochemistry and histology in interferon naive patients with chronic hepatitis C. Higher doses and prolonged durations are more effective, but associated with more frequent adverse events. Interferon is associated with similar benefits in patients with cirrhosis, but the efficacy in patients with normal aminotransferases is unproven.

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.

An analysis of acute changes in interleukin-6 levels after treatment of hepatitis C with consensus interferon

Cytokine production has been implicated in the antiviral response to interferon-alpha (IFN-alpha) in hepatitis C and in the development of IFN-alpha-related side effects. We characterized acute changes in serum cytokine levels following administration of a single dose of consensus IFN (IFN-con1) and during continuous treatment of chronic hepatitis C patients. Serum samples were collected at baseline, at multiple times early after IFN administration, and weekly thereafter. Viral RNA titers were assessed by RT-PCR, and viral kinetics were followed. ELISA assays were used to measure IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, and IL-16. Serum cytokine levels were low at baseline. IL-6 was detected in patients with hepatitis C but not in healthy control subjects by either ELISA or RT-PCR, indicating that low levels of circulating IL-6 were associated with hepatitis C infection. None of the cytokines measured increased significantly after IFN administration except for IL-6. IL-6 levels rose rapidly, peaked at 6-15 h in a dose-dependent manner, and returned to baseline by 48 h in both patients receiving a single dose of IFN and those receiving continuous treatment. This was confirmed by RT-PCR. Pretreatment IL-6 levels were directly correlated with area under the curve (AUC) for IL-6 during the 24 h after IFN dosing (r = 0.611, p = 0.007). Viral titers decreased within 24-48 h after a single dose of IFN-con1. Changes in hepatitis C RNA titers were not significantly associated with pretreatment IL-6 levels or with changes in IL-6 levels. In conclusion, (1) baseline serum cytokine levels, except for IL-6, were low or within the normal range in patients with hepatitis C, (2) IL-6 levels were detected in some patients with hepatitis C before treatment but not in healthy controls, (3) IL-6 levels increased acutely after a single dose of IFN-alpha, and IL-6 induction was related to baseline IL-6 level, and (4) changes in IL-6 levels did not correlate with the early virologic response to IFN.

Management of interferon therapy nonresponders

Despite improvements in the therapies for chronic hepatitis C virus (HCV) over the past several years, many patients still fail to become hepatitis C virus ribonucleic acid (HCV-RNA) undetectable during treatment and are classified as nonresponders. Providing treatment recommendations for these patients requires that the likelihood of achieving any benefit from another course of therapy be balanced with the natural history of chronic HCV. The management of nonresponders represents the most challenging of all aspects in the care of patients with chronic HCV. Retreatment of interferon non-responders with interferon and ribavirin has yielded a long-term virologic benefit in only 10% to 25% of patients. The efficacy of peginterferon and peginterferon with ribavirin for nonresponders has yet to be defined.