- Subjects must be previously treated with pegylated interferon (PEG) or interferon (INF) with or without ribavirin (RBV) and either did not achieve a sustained viral response (undetectable HCV RNA) six months after cessation of anti-viral therapy, or did not tolerate PEG or INF with or without RBV therapy. Subjects who have contraindications to receiving PEG or INF with or without RBV may also be eligible.