Maintenance therapy with ribavirin in patients with chronic hepatitis C who fail to respond to combination therapy with interferon alfa and ribavirin. Evaluation of ribavirin efficacy and tolerance in subjects with chronic hepatitis C virus infection. Antiviral action of ribavirin in chronic hepatitis C. Ribavirin treatment for patients with chronic hepatitis C: results of a placebo-controlled study. Retreatment of hepatitis C non-responsive to interferon. A placebo controlled randomized trial of ribavirin monotherapy versus combination therapy with Ribavirin and Interferon in 121 patients in the Benelux [ISRCTN53821378]. A prospective and randomized study using ribavirin as monotherapy for the treatment of naïve patients with chronic hepatitis C. Modulation of hepatitis C virus quasispecies heterogeneity by interferon-alpha and ribavirin therapy. Tolerance and efficacy of oral ribavirin treatment of chronic hepatitis C: a multicenter trial. The effect of interferon alfa and ribavirin combination therapy in naive patients with chronic hepatitis C. Ribavirin and interferon alfa-2b in chronic hepatitis C: assessment of possible pharmacokinetic and pharmacodynamic interactions. 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.
To assess the efficacy and safety of maintenance therapy with ribavirin alone in chronic hepatitis C, 108 patients were treated with the combination of interferon alfa and ribavirin for 24 weeks; those who failed to have a virologic response were offered enrollment in a randomized, double-blind, controlled trial of ribavirin (1,000-1,200 mg daily) versus placebo for the subsequent 48 weeks. Patients were monitored at regular intervals with symptom questionnaires, serum aminotransferase levels, hepatitis C virus (HCV) RNA levels, and complete blood counts and underwent liver biopsy at the completion of therapy. Among 108 patients, 50 were still HCV RNA positive after 24 weeks of treatment, of whom 34 agreed to be randomized to continue either ribavirin monotherapy or placebo. Among 17 patients who received placebo, there was no overall improvement in symptoms, serum alanine aminotransferase (ALT) levels, HCV RNA levels, or hepatic histology. Among the 17 patients who received ribavirin, serum ALT levels and necroinflammatory features of liver histology were improved, whereas symptoms, HCV RNA levels, and hepatic fibrosis scores were not changed significantly from baseline. Responses to ribavirin seemed to be categorical, such that 8 patients (47%) had definite improvement in liver histology. Patients with improved histology had improvements in serum ALT levels both on combination therapy and after switching to ribavirin monotherapy. In conclusion, continuation of ribavirin monotherapy may maintain serum biochemical improvements that occur during interferon-ribavirin combination therapy in some patients and that these improvements are often associated with decreases in necroinflammatory changes in the liver. Whether these improvements will ultimately result in prevention of progression of hepatitis C requires further study. Reports by hepatologists indicated that anti-HCV antibodies might be detected in 71% to 84% of cases of post-transfusion hepatitis and in up to 50% of cases of sporadic non-A non-B hepatitis. Anti-HCV antibodies were detected in 0.05-1% of blood donors with normal alanine transaminase (ALT) levels and negative anti-HBc screening. Anti-HCV antibodies were found in 67% of patients with a history of intravenous drug abuse or autoimmune hepatitis, and in 10-30% of patients with hepatocellular carcinoma. This indicated that hepatitis C virus was a major cause of the acute and chronic hepatitis throughout the world.
                This was a multicenteric, international, double-blind, randomized, placebo-controlled study. After the eight-week screening period, patients were randomized to receive daily ribavirin 1200 mg or placebo, during the 48-week treatment period. Follow-up observations were performed during a 16 week post-treatment period. Up to 80 male and female outpatients with mild to moderate chronic active hepatitis C virus infection were enrolled in this study.
                During the treatment period ALT values were significantly lower in the ribavirin group. Neither in the ribavirin group, nor in the placebo group significant statistical differences of the HCV RNA values were found. Significantly lower portal inflammation was noticed in ribavirin group after the treatment. Analysis of laboratory data demonstrated that ribavirin therapy was associated with mild to moderate reversible anemia. Investigator's evaluation of the effect of the therapy on patient's well being showed statistically significant differences in the benefit of the ribavirin group.
                In this study ribavirin was more effective than placebo in reducing ALT levels during the treatment period of the applied therapy in patients with chronic active hepatitis C. In the patients with chronic hepatitis C, the addition of ribavirin to interferon (IFN)-alpha significantly increases the virologic responses. Our aim was to assess the antiviral action of ribavirin on hepatitis C virus (HCV) as a function of ribavirin pharmacokinetics and to evaluate the influence of this antiviral effect on IFN-alpha efficacy.
                Forty-five patients with chronic hepatitis C (genotype 1b) received various schedules of IFN-alpha and/or ribavirin administration. Frequent blood sampling was performed for HCV RNA kinetics and ribavirin pharmacokinetics assessment.
                Ribavirin monotherapy induced a significant, moderate, early, and transient viral load decrease in approximately half of the patients. The occurrence of this effect was associated with longer ribavirin clearance half-lives and higher serum ribavirin concentrations. Ribavirin antiviral effect partly reduced the rebound preceding the second IFN-alpha injection in patients receiving standard IFN-alpha 3 times per week plus ribavirin. The magnitude of the rebound was inversely related to ribavirin concentrations. These patients subsequently experienced a slow, but significant, second slope of viral decrease and cleared HCV RNA. The addition of ribavirin to daily IFN-alpha monotherapy did not have any impact on the second phase of viral decline.
                Ribavirin exerts a significant, moderate, and transient antiviral effect in a significant proportion of patients with chronic hepatitis C. The antiviral effect of ribavirin correlates with ribavirin pharmacokinetics and is partly responsible for the improved efficacy of the combination of standard IFN-alpha and ribavirin compared with IFN-alpha monotherapy by increasing the incidence of the initial response. Small, uncontrolled studies of ribavirin for patients with chronic hepatitis C have reported efficacy in chronic hepatitis C. We have evaluated the efficacy and safety of a 24-week course of oral ribavirin in patients with chronic hepatitis C, compared to placebo.
                A total of 114 patients were randomised to ribavirin or placebo. Ribavirin was administered in doses of 1000 or 1200 mg/day for 24 weeks. Efficacy was determined in the intention-to-treat population: 76 received ribavirin and 38 placebo.
                Ribavirin was significantly more effective than placebo in reducing and normalising serum ALT levels: 42/76 (55%) of ribavirin-treated patients vs 2/38 (5%) placebo recipients had either normalisation of the ALT levels or a reduction from baseline of at least 50% (p < 0.001). ALT levels were normal in 22/76 (29%) of ribavirin-treated patients vs 0/38 placebo recipients (p < 0.001). Twenty-four weeks after stopping ribavirin, the majority of patients had abnormal ALT levels. There was no difference between the treatment groups in reduction or disappearance of HCV-RNA levels. HCV RNA disappeared during treatment in 3% of ribavirin-treated patients and 3% of placebo recipients. More ribavirin than placebo patients showed improvement in total Knodell score (45% vs 31%), but these differences were not statistically significant. Analysis of each component of a histology activity index revealed no statistically significant differences between treatment groups. Ribavirin patients had fewer lymphoid aggregates than did placebo recipients at the post-treatment assessment (p = 0.05). Ribavirin was associated with reversible haemolytic anaemia: a fall in haemoglobin occurred in 3% of placebo- and 32% (25/78) of ribavirin-treated patients, respectively (p < 0.001).
                These data indicate that ribavirin was no more effective than placebo in reducing or eliminating HCV-RNA levels, and was not significantly more effective than placebo in improving hepatic histology after 6 months of treatment. The role of a 6-month treatment of chronic hepatitis C with ribavirin alone, without a significant effect on HCV RNA, is therefore limited. Evidence based medicine depends on unbiased selection of completed randomized controlled trials. For completeness it is important to publish all trials. This report describes the first large randomised controlled trial where combination therapy was compared to placebo therapy and to ribavirin monotherapy, which has not been published until now.
                One hundred and twenty one patients with chronic hepatitis C and elevated transaminases who did not respond to previous treatment with standard interferon monotherapy, were included from 16 centers in Belgium, the Netherlands and Luxembourg between 1992 and 1996. Patient poor-response characteristics were: genotype 1 (69%), HCV RNA above 2 x 10(6) copies/ml (55%) and cirrhosis (38%). Patients were randomized to 6 months combination therapy with interferon alpha-2b (3 MU tiw) and ribavirin (1000-1200 mg/day), 6 months ribavirin monotherapy (1000-1200 mg/day) or 6 months ribavirin placebo. The study was double blinded for the ribavirin/placebo component. One patient did not fit the entry criteria, and 3 did not start. All 117 patients who received at least one dose of treatment were included in the intention to treat analysis.
                At the end of treatment, HCV RNA was undetectable in 35% of patients on combination therapy and in none of the patients treated with ribavirin monotherapy or placebo. The sustained virological response rate at 6 months after therapy was 15% for patients treated with interferon and ribavirin. During the 6 months treatment period 13% of patients on interferon ribavirin combination therapy, 13% of patients on ribavirin monotherapy and 11% of patients on placebo withdrew due to side effects or noncompliance. At 24 weeks of treatment the mean Hb level was 85% of the baseline value, which means a mean decrease from 9.1 mmol/l to 7.8 mmol/l. The Hb levels at the end of treatment were not significantly different from patients treated with ribavirin monotherapy (p = 0.76). End of treatment WBC was significantly lower in patients treated with combination therapy, compared to ribavirin (p < 0.01) as well as for patients treated with ribavirin monotherapy compared to placebo (p < 0.01).
                This belated report on the only placebo controlled study of interferon ribavirin combination therapy in non responders to standard doses of interferon monotherapy documents the effectiveness, be it limited, of this approach as well as the dynamics of the effects on blood counts. In order to evaluate the response to ribavirin in previously untreated patients with chronic hepatitic C, 39 patients were selected for a double-blind prospective and randomized trial, and divided into two groups: ribavirin-group (19 patients) and placebo-group (20 patients). Ribavirin was administered orally for 24 weeks (600 mg/day, followed by 1,000 mg/day and 1,200 mg/day each one for 8 weeks). After 3 months of drug administration, the patients were evaluated by measuring biochemical, virologic and histologic responses. After this phase, ribavirin was offered to the patients who had received placebo (second phase). The results showed that the patients who received ribavirin showed a higher reduction in serum alanine aminotransferase (ALT) activity than patients in the placebo group. Among the patients in the ribavirin-group, a complete biochemical response (ALT levels normalized) was observed in 3 patients (16%), and a partial response (reduction greater than 50% of the initial value of ALT activity) in 4 (21%). In the 20 patients in the placebo group, only 1 showed a partial response (5%). In the second phase of the study, among 16 patients who received ribavirin, 4 (25%) showed a complete and 5 (31%) a partial biochemical response. HCV-RNA did not become negative in any patient during the two phases. A reduction in the score of portal and lobular activity was observed in patients who received ribavirin, but statistical analysis did not identify differences. This study showed that ribavirin alone induces a biochemical response (ALT reduction) in some patients with chronic hepatitis C, which may be associated with a reduction in hepatic inflammatory activity reduction, but the changes are not sufficient to recommend initial monotherapy with ribavirin. To determine the effects of interferon-alpha (IFN-alpha) and ribavirin therapy on hepatitis C virus (HCV) quasispecies heterogeneity, 29 patients with chronic HCV infection treated with either IFN-alpha (n = 15), ribavirin (n = 7) or placebo (n = 7) were studied. HCV quasispecies heterogeneity was determined by single-strand conformational polymorphism (SSCP) analysis of the HCV E2 hypervariable region 1 (HVR1). For patients receiving IFN-alpha, HVR1 was amplified in 14 of 15 patients before, and in six of seven patients after therapy. After controlling the amount of amplicon loaded, a reduction in the number of SSCP bands was observed with IFN-alpha therapy (median number of SSCP bands per patient was eight before therapy and two after therapy). In the seven patients within each of the ribavirin- and placebo-treated groups, there was no significant difference in the viraemia level, number of SSCP bands per patient or the SSCP band pattern, before and after therapy. These findings suggest that at the doses given, IFN-alpha, but not ribavirin, exerts a selective pressure on HCV quasispecies heterogeneity. Hepatitis C is a common cause of chronic liver disease that may progress to cirrhosis. We conducted a multicenter double-blind placebo-controlled trial of ribavirin 600 mg given orally twice daily for 36 weeks with follow-up off therapy for an additional 16 weeks. Fifty-nine patients with compensated chronic hepatitis C were entered. Efficacy was measured at the end of therapy and after follow-up by normalization of alanine aminotransferase (ALT), improvement in liver histology, reduction in hepatitis C virus (HCV) RNA level and improvement of symptoms. Among the ribavirin recipients, 12 of 29 (41.4%) had normal ALT values at 36 weeks compared with only 1 of 30 (3.3%) placebo recipients (P < .001). No patient maintained a normal ALT when therapy was stopped. No significant decrease in level of HCV RNA was observed during the study. Histological improvement among subjects who normalized ALT (-1.67 Knodell index) was significantly greater than that in other treated patients (+0.33 Knodell index; P < .05). Fatigue improved in 19.2% of ribavirin-treated subjects and in 8.3% of placebo recipients whereas no worsening of fatigue was reported by ribavirin recipients compared with 16.7% of controls. This difference in fatigue was significant at weeks 36 and 52 (P < .05; .02, respectively). Adverse events were generally comparable between treatment groups except for a reversible hemolytic anemia experienced by ribavirin recipients. Chest pain was noted in four patients on ribavirin. Ribavirin was well tolerated and improved aminotransferase values and reduced fatigue in patients with hepatitis C viral infection while treatment was being administered. Because this action was produced without change in viral level, the mechanism of action of this agent requires further investigation. Chronic hepatitis C may lead to cirrhosis and hepatocellular carcinoma in a subset of patients. Because response rates with interferon alfa therapy are unsatisfactory, new therapies are needed.
                We conducted a three-arm, randomized trial in 45 interferon-naive men (mean age 40.6 +/- 12 years) with chronic hepatitis C to compare treatments: group A, ribavirin alone (15 mg/kg daily for 6 months); group B, interferon alone (3 MU thrice weekly for 6 months); and group C, interferon plus ribavirin at the above doses. Histologic outcomes of therapy were assessed by pretreatment and post-treatment liver biopsies.
                In group A, alanine aminotransferase levels normalized during therapy in 66% of those with HCV-1b and 34% of those with HCV-2a, but all patients relapsed after treatment ended. In group B, alanine aminotransferase levels normalized during treatment in 66%, 75%, and 100% of patients infected with HCV-1b, HCV-2a, and HCV-3, respectively; however, a sustained response was noted in only 25% of those with HCV-3. In group C, a sustained normalization of alanine aminotransferase with negative serum HCV RNA was seen in 20% of those with HCV-1b, 40% of those with HCV-2a, and 75% of those with HCV-3 12 months after therapy. One year after therapy ended, group C demonstrated a significant sustained response (47%) as well as a significant reduction in piecemeal necrosis and portal inflammation (p < 0.05).
                Combination therapy was significantly superior to ribavirin or interferon monotherapy in producing a sustained response in interferon-naive patients with chronic hepatitis C (p < 0.05). The results of our study suggest that ribavirin potentiates the effect of interferon therapy in chronic hepatitis C. The primary objective of this study was to determine whether pharmacokinetic interactions occurred between interferon alpha-2b (IFN) and ribavirin in patients with chronic hepatitis C infections. Additionally this study assessed the single and multiple-dose pharmacokinetics of ribavirin and IFN, and compared the safety, tolerability and antiviral pharmacodynamics of IFN plus ribavirin compared with either drug alone.
                In this open label parallel group study, patients with chronic hepatitis C were randomized to receive IFN 3 million IU thrice weekly s.c. alone, ribavirin 600 mg twice daily p.o. alone or both drugs in combination over 6 weeks. Single and multiple dose pharmacokinetics and indices of antiviral pharmacodynamics were assessed during weeks 1 and 6, along with safety assessments during the study.
                The range of mean ribavirin terminal phase half-lives after single doses was 44-49 h. Comparison of week 1 and week 6 AUC(0,12h) values showed accumulation in plasma of approximately 6-fold. The range of mean washout half-lives after week 6 was 274-298 h, reflecting release of ribavirin from deep compartment stores. The range of single and multiple dose IFN terminal phase half-lives was 5-7 h. IFN demonstrated an increase in bioavailability (approximately 2-fold) upon multiple dose administration. Ribavirin and IFN pharmacokinetic parameters for combined ribavirin and IFN were similar to those during monotherapy with either compound, although the power of this study to detect differences was low. Serum HCV-RNA titers and ALT concentrations were reduced by IFN alone, ribavirin alone reduced ALT concentrations only, and combined IFN plus ribavirin produced numerically greater falls in both measurements than either treatment alone. Serum concentrations of neopterin and activity of 2',5'-oligoadenylate synthetase (2'5'-OAS) were increased by IFN alone and in combination with ribavirin, whereas serum 2'5'-OAS activity was decreased and neopterin concentrations unaltered by ribavirin monotherapy. IFN and ribavirin monotherapy produced characteristic changes in safety laboratory tests (IFN--reductions in white cells, neutrophils and platelets; ribavirin--reduced haemoglobin) and characteristic adverse event profiles (IFN--headache, flu-like symptoms, fatigue, anorexia, nausea, myalgia, and insomnia; ribavirin--headache, fatigue, myalgia, and pruritus). There was no additive effect of combination therapy on safety laboratory tests or reported adverse events. All changes were fully reversible upon treatment cessation.
                There was no evidence of pharmacokinetic interactions between IFN and ribavirin in this study. There were numerical trends indicating that the combination of IFN and ribavirin reduced titers of HCV-RNA to a greater extent than did either treatment alone, and the safety profile of combination therapy was similar to those of both monotherapy treatments. 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.
Ribavirin seems without beneficial effects on serum virological response and liver-related morbidity or mortality, and significantly increased the risk of adverse reactions. Ribavirin monotherapy seems significantly inferior to interferon monotherapy. The total number of included patients is small, and more trials are perhaps needed. The use of ribavirin monotherapy for chronic hepatitis C cannot be recommended outside randomised trials.