This is a study designed to identify a dose of NIM811 that has a good safety profile, is well tolerated when co-administered with SOC, and provides a clinically meaningful effect in viral load reduction compared to SOC alone. This information will be used to support doses selected for future studies.

Inclusion criteria:

Patients eligible for inclusion in this study have to fulfill all of the following criteria:

• chronic hepatitis C genotype-1
• HCV-RNA should be ≥ 4 x 105 IU/mL at screening
• Recipient of prior long acting interferon and ribavirin treatment for at least 12 weeks, with documented negative serum HCV RNA on treatment, who subsequently becomes serum HCV RNA positive after stopping treatment ("relapser"). Patients must have been off all treatment for at least 3 months prior to start of study (Visit

Exclusion criteria:

• Use of any HCV treatment ≤ 3months prior to study start
• Prior receipt of any investigational anti-HCV therapy which is not IFN or RBV
• Women of child-bearing potential unless they are post-menopausal or use predefined acceptable methods of contraception
• Pregnant or breastfeeding women
• Evidence of cirrhosis, hepatic decompensation, other than HCV liver disease, HBV or HIV infection
• Specified abnormalities in lab values of amongst others hemoglobin, WBC, ANC, platelets
• History of treatment for depression
• Steroid/immunosuppression drug use 3 months prior to study start Other protocol-defined inclusion/exclusion criteria may apply