Background: Many patients with chronic hepatitis C have not responded to therapy with pegylated interferon plus ribavirin.
Objective: To evaluate use of peginterferon-alpha2a plus ribavirin to re-treat nonresponders to peginterferon-alpha2b plus ribavirin.
Design: Randomized, parallel-group trial conducted between September 2003 and February 2007. Patients and researchers were not blinded to intervention assignment. Random assignment was centralized, computer-generated, and stratified by geographic region, hepatitis C virus (HCV) genotype, and histologic diagnosis.
Setting: 106 international centers.
Patients: 950 nonresponders to 12 or more weeks of therapy with peginterferon-alpha2b plus ribavirin.
Intervention: Peginterferon-alpha2a, 360 microg/wk, for 12 weeks, then 180 microg/wk to complete 72 weeks (group A) or 48 weeks (group B), or peginterferon-alpha2a, 180 microg/wk for 72 weeks (group C) or 48 weeks (group D). All patients received ribavirin, 1000 or 1200 mg/d.
Measurements: Sustained virologic response (SVR), defined as undetectable (<50 IU/mL) HCV RNA levels 24 weeks after the end of treatment.
Results: The SVR rates in groups A (n = 317), B (n = 156), C (n = 156), and D (n = 313) were 16%, 7%, 14%, and 9%, respectively (relative risk [RR] for group A vs. group D [the primary comparison], 1.80 [95% CI, 1.17 to 2.77]; P = 0.006). Extended treatment duration increased SVR rates (16% for 72 weeks [groups A and C] vs. 8% for 48 weeks [groups B and D]; RR, 2.00 [CI, 1.32 to 3.02]; P < 0.001). Complete viral suppression (HCV RNA level <50 IU/mL)at week 12 was achieved in 21% of patients in groups A and B and 13% of those in groups C and D. Rates of SVR were 49% (77 of 157 patients) and 4% (32 of 719 patients) among those with and without complete viral suppression at week 12, respectively.
Limitation: Nonresponders to peginterferon-alpha2a plus ribavirin were not evaluated.
Conclusion: Re-treating nonresponders to therapy with peginterferon-alpha2b plus ribavirin for 72 weeks significantly increases SVR rates compared with re-treating them for 48 weeks. The overall SVR rate was low, but patients who are most likely to respond to re-treatment can be identified at week 12.
Primary funding source: Roche.