Retreatment of patients with chronic hepatitis C not responding to interferon/ribavirin combination therapy with daily interferon plus ribavirin plus amantadine

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.

Standard interferon-alpha in combination with ribavirin for hepatitis C patients with advanced liver disease and thrombocytopenia

BACKGROUND AND AIM

Patients with advanced liver disease due to thrombocytopenia and chronic infection with hepatitis C virus (HCV) are difficult to treat in view of concerns about the efficacy and safety of interferon-based therapy. Nevertheless, antiviral therapy might have a substantial benefit in these patients as it potentially minimizes disease progression and prevents recurrence after liver transplantation. We evaluated the safety, efficacy and tolerability of standard interferon-alpha in an accelerating dose regimen in combination with ribavirin in patients with HCV-induced liver cirrhosis and thrombocytopenia.

PATIENTS

Nine patients (M=8, age: 48.4 +/- 9.9, mean +/- SD) with HCV-related advanced liver disease and thrombocytopenia were prospectively investigated. The Child-Pugh stage was A in six patients and B in three, the MELD score was 11 [6-17] (median [range]). Four patients were interferon naive. HCV-genotype distribution was 1b (n=3), 3a (n=4) and 4 (n=2). The patients received 1-1.5 MU/d standard interferon-a2b with increasing dose regimen and weight-based ribavirin for 48 weeks (genotype 1), or 24 weeks (genotype 3), or until liver transplantation, respectively.

RESULTS

The baseline platelet count was 64.3 +/- 8.7 (G/l, mean +/- SD) and remained remarkably stable during treatment (58.0 +/- 12.4 G/l at week 4, 51.7 +/- 20.5 G/l at week 8, P=0.1). All patients had adverse events such as weight loss, fever and anorexia. Hospitalization because of decompensation or infection was necessary in three patients. Three patients underwent liver transplantation. A virological response on treatment was achieved in eight patients and sustained in three (33.3%) patients.

CONCLUSION

Treatment with standard interferon-alpha2b/ribavirin could be of benefit in patients with advanced liver cirrhosis and thrombocytopenia however, a vigilant monitoring of these high risk patients is mandatory.

Triple antiviral therapy in HCV positive patients who failed prior combination therapy

AIM: To assess the efficacy of triple therapy (peginte-rferon or high dose standard interferon, plus ribavirin and amantadine) in nonresponders to prior combination therapy.

METHODS: A total of 196 patients were enrolled in a multicenter, open, randomized study. Patients were given 180 μg/wk of peginterferon-alpha-2a (40 kDa) plus ribavirin (800-1000 mg/d) and amantadine (200 mg/d) for 48 wk (group A) or interferon-alpha-2a (6 MU/d for 4 wk, 3 MU/d for 20 wk, and 3 MU tiw for 24 wk) plus ribavirin (800-1000 mg/d) and amantadine (200 mg/d) for 48 wk (group B).

RESULTS: Overall sustained virologic response (SVR) was 26.6% (32.1% and 19.5% in group A and B, P = 0.057). Baseline ALT >120 UI/L (OR 2.4; 95% CI:1.11 to 5.20; P = 0.026) and HCV RNA negativity after 12 wk (OR 8.7; 95% CI: 3.87 to 19.74; P < 0.0001) were independently associated with SVR. Therapy discontinuation occurred less frequently in patients treated with peginterferon than standard interferon (P = 0.036).

CONCLUSION: More than 25% of nonresponders to combination therapy can eradicate HCV infection when retreated with triple therapy, especially if they have a high baseline ALT and are treated with pegylated interferon.

Randomized, double-blind, placebo-controlled study of peginterferon alfa-2a (40KD) plus ribavirin with or without amantadine in treatment-naïve patients with chronic hepatitis C genotype 1 infection

BACKGROUND/AIMS

Amantadine may augment virological response rates to interferon-based therapy in chronic hepatitis C patients. Using a novel design, amantadine was studied in naïve genotype 1 patients treated in combination with peginterferon alfa-2a (40KD)/ribavirin.

METHODS

Patients enrolled in this randomized, placebo-controlled multicenter trial were stratified by single-dose interferon sensitivity (stratum I, 24-h HCV-RNA decline >1.4-log10; II, 0.8-1.39-log10; III, <0.8-log10; a reliable means of identifying nonresponders to interferon/ribavirin) and fibrosis grade (F0/1/2 vs. F3/4) at baseline. All patients received peginterferon alfa-2a (40KD) 180 microg/week plus ribavirin 1000-1200 mg/day and were randomized to receive amantadine 100 mg twice daily (N = 114) or placebo (N = 95) for 48 weeks.

RESULTS

Week-24 virological response rates in strata II and III, the primary outcome, were similar in patients treated with amantadine (63.7%) or placebo (65.7%), as were sustained virological response rates at week 72 (46.5 and 51.6%, respectively). Adverse event profiles were similar and amantadine did not improve health-related quality of life compared with placebo. Interferon sensitivity was the only significant predictor of treatment outcome.

CONCLUSIONS

Adding amantadine to peginterferon alfa-2a (40KD)/ribavirin combination therapy does not augment virological response rates in genotype 1 patients. Virological response was almost exclusively determined by interferon sensitivity at baseline.