Evaluation of efficacy of antiviral therapy for chronic hepatitis C: a EUROHEP Consensus Report on response criteria

Interferon-alpha plus amantadine in chronic hepatitis C resistant to interferon alone: a pilot randomized study

The optimal therapy for patients with chronic hepatitis C who have not responded to interferon (IFN) is still an unsolved issue. The aim of this study was to evaluate the efficacy and tolerability of a high dose of IFN-alpha2a plus amantadine for chronic hepatitis C patients who were non-responders to a previous course of IFN. Forty consecutive patients with chronic hepatitis C, genotype 1b, who had not responded to IFN-alpha, were randomized to receive: (i) IFN 4.5 MU daily plus amantadine 200 mg/day for 4 weeks and then IFN 6 MU thrice weekly plus amantadine 200 mg/day for an additional 5 months (group A) or (ii) IFN alone at the same dosage and duration (group B). After 1 month of therapy, normal alanine aminotransferase (ALT) values were observed in three of 21 (14.3%) patients in group A and in three of 19 (15.8%) in group B; serum hepatitis C virus (HCV)-RNA clearance was observed in one patient (4.8%) in group A and in six (31.6%) in group B. At the end of treatment, six patients (28.6%) in group A and three (15.8%) in group B had normal ALT levels; however, HCV-RNA in serum was detectable in all of them at levels comparable to the basal values; an ALT relapse occurred within 3 months of stopping therapy. The combination of daily IFN plus amantadine was ineffective in this setting.

Methodological issues in papers on IFN therapy: time for reappraisal

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

New treatment strategies in non-responder patients with chronic hepatitis C

There is solid evidence that retreatment of non-responders with standard regimens of interferon monotherapy is of no clinical value. On the other hand, combination therapy with interferon and ribavirin now produces sustained response rates in non-responders similar to those of interferon monotherapy in untreated patients. Consequently, retreatment of non-responders with the combination of interferon-ribavirin appears to be a valid treatment option. The efficacy of retreatment with the interferon-ribavirin combination can probably be increased by modifying the first weeks of interferon therapy from standard (3 MU tiw) to induction (10 MU daily), and by extending the treatment period to 12 months. In the next few years, the additive value of amantadine to interferon or to interferon-ribavirin combination in inducing sustained viral clearance should be explored. For the many patients who still do not respond with viral clearance despite these new approaches, the goal of therapy might be shifted towards persistent ALT normalization in order to reduce the progression of liver disease. Drugs that can normalize serum ALT such as interferon, ursodeoxycholic acid, ribavirin and glycyrrhizin should be evaluated for this objective.

Importance of pretreatment viral load and monitoring of serum hepatitis C virus RNA in predicting responses to interferon-alpha2a treatment of chronic hepatitis C. Hanshin Chronic Hepatitis C Study Group

The aim of this study was to determine what factors correlate with a favorable response to interferon-alpha2a (IFN-alpha2a) treatment in chronic hepatitis C. Fifty patients with chronic hepatitis C who received a 26-week treatment with IFN-alpha2a (474 million units in total) were assessed for pretreatment parameters and biochemical and virologic events during the treatment. According to biochemical and virologic responses to the treatment, 16 patients (32%) were categorized as sustained complete responders (SR), 13 (26%) as initial complete responders (IR), and 21 (42%) as nonresponders (NR). By multivariate analysis, a low viremia level was the only independent predictor of SR among pretreatment parameters (p = 0.0088). The percentage of patients showing hepatitis C virus RNA negativity at 2 and 12 weeks of treatment was significantly higher in SR (94% and 100%, respectively) or IR (69% and 92%, respectively) than in NR (14% and 33%, respectively) (p = 0.001). In contrast, the normalization of serum alanine aminotransferase levels at both time points failed to differentiate among SR, IR, and NR. These results indicate that monitoring of serum hepatitis C virus RNA at an appropriate time during treatment in addition to determination of pretreatment viral load is important in predicting responses to IFN-alpha2a treatment.