This Phase 3 clinical study is designed to evaluate the safety, tolerability, and efficacy of two dose levels of Infergen (interferon alfacon-1, CIFN) plus Ribavirin administered daily for 48 weeks and no treatment in patients chronically infected with hepatitis C who are nonresponders to previous pegylated interferon alfa plus ribavirin therapy and participated during at least 24 weeks of no treatment in IRHC-001.