Conditions: Chronic Hepatitis C
Keywords: Hepatitis C interferon alfa ribavirin interferon alfacon-1 antiviral therapy
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 64
Healthy volunteers: no

Brief summary:
Data have suggested that consensus interferon (CIFN) has greater antiviral activity in vitro compared with interferon alfa-2a or alfa-2b. Several clinical studies also suggest that CIFN has greater antiviral activity in patients with genotype 1 hepatitis C infection, particularly if given as a daily injection. These data indicate that the use of a regimen of daily CIFN and ribavirin will lead to greater virologic response rates compared with pegylated interferon alfa-2b and ribavirin in patients with genotype 1 infection, with comparable adverse events. Emerging data indicate that HCV genotype 1 patients with a delayed virologic response to initial therapy may benefit from an extended duration of therapy. Therefore, the goals of this pilot study are to determine the tolerability and efficacy of daily CIFN plus ribavirin when given for 52 weeks or an extended duration of therapy. The target population will consist of "difficult-to-treat" patients, defined as having the following characteristics: genotype 1, a North American patient population, predominantly male gender, and no specific exclusions for pre-existing psychiatric or substance abuse co-morbidities.

Detailed description:
Current treatment for hepatitis C is a pegylated interferon alfa plus ribavirin. This treatment is inadequate for patients with HCV genotype 1, since the majority of patients do not respond (termed non-responders) or respond but relapse (termed relapsers) following termination of these treatments. Data from the Veterans Health Administration (VHA) Hepatitis C Registry and community hospitals indicate that the large majority of patients identified with hepatitis C have characteristics associated with a poor treatment response and remain untreated at this time. Data have suggested that consensus interferon (CIFN, CIFN or interferon alfacon-1) has greater antiviral activity in vitro compared with interferon alfa-2a or alfa-2b. Preliminary data indicate that more patients with genotype 1 can respond to CIFN and ribavirin than current standard treatments, due to the fact that approximately 25% of patients who are nonresponders to pegylated interferon and ribavirin may have a sustained response to a regimen of daily CIFN and ribavirin. Furthermore, difficult to treat patients may benefit from a longer duration of therapy than the standard 48 week regimen based on when an initial virologic response to therapy occurs.

Aims: To determine the safety and efficacy of (A) daily CIFN (15 mcg/d sq) and ribavirin (1-1.2 gm/d PO) given for 52 weeks, vs (B) daily CIFN (15 mcg/d sq) and ribavirin (1-1.2 gm/d PO) given for 52 to 72 weeks for treatment-naïve patients with hepatitis C genotype 1, with treatment duration based on the virologic response during the initial 24 weeks.

Methods: Patients who meet eligibility criteria will be stratified by race and randomized to one of two treatment arms, and all patients will have viral kinetics measured by quantitative PCR at weeks 4,8,12,16,20 and 24. Patients in treatment arm A will follow "standard" stopping rules, i.e., if there is not a 2-log drop in viremia by 12 weeks the treatment will be discontinued, otherwise they will all receive 52 weeks of treatment if they also are qualitative PCR negative by week 24. In treatment arm B the patients will be monitored monthly until they have a virologic response (defined as \>2 log drop in viral levels from baseline) by quantitative PCR for up to 24 weeks. Once they have a virologic response by quantitative PCR their treatment will be continued for an additional 48 weeks. In both groups, treatment will be stopped if the patients do not become negative for HCV RNA by qualitative PCR by 24 weeks on therapy. A total of 192 patients at up to 10-20 sites will be recruited. The primary endpoint would be the number who achieve a sustained virologic response; secondary endpoints are the percentage of patients who complete therapy, have significant adverse events, and the relationship of early virologic response at each 4 week period between 4 and 24 weeks and those who achieve a sustained virologic response.

Sample size determination: To detect an absolute difference of 20% or more in sustained virologic response between treatment arms A and B; the Log-rank test is performed at the alpha level of .05 and the test is maintained at least 80 percent statistical power; it is estimated that a total of 96 patients in each treatment arm will be required.

Analysis: Univariate and multivariate analysis will be used to determine factors associated with final endpoints. Subgroup analyses will be done based on time to early virologic response and duration of therapy each stratification. The primary and secondary endpoints will be determined on an intention-to-treat basis starting with all patients that receive at least one dose of study medications. The primary and secondary endpoints will also be determined in a per-protocol analysis on those patients who take 80% of the prescribed CIFN and 80% of the prescribed ribavirin for 80% of the time.

Significance: The current initial treatment of pegylated interferon alfa and ribavirin for patients with hepatitis C who are genotype 1 and have other "difficult-to-treat" characteristics is inadequate. The results of this trial are needed to demonstrate the safety and efficacy of two regimens of daily CIFN and ribavirin. Since the large majority of hepatitis C patients in VA and other community hospitals fall into this category, the results of this trial may influence the potential treatments recommended for these patients.

Arms:
arm 1: Daily CIFN (15 mcg/day SQ) and RBV (1-1.2 g/d PO) given 52 weeks (group A) arm 2: CIFN (15 mcg/day SQ) and RBV (1-1.2 g/d PO) given for 52-72 weeks (from time of viral response +48 weeks) (group B)

Interventions: intervention 1: consensus interferon (Interferon Alfacon-1) and ribavirin intervention 2: Consensus Interferon alfa (CIFN) and ribavirin
Intervention descriptions: intervention 1: CIFN (15 mcg/day SQ) and RBV (1-1.2 g/d PO) given for either 52 weeks (group A, n = 33) or 52-72 weeks (from time of viral response +48 weeks) (group B) intervention 2: CIFN (15 mcg/day SQ) and RBV (1-1.2 g/d PO) given for either 52 weeks (group A, n = 33) or 52-72 weeks (from time of viral response +48 weeks) (group B)

Protocol document: