This proof of concept study is designed to evaluate the safety, tolerability, pharmacokinetics, and antiviral activity of TD-6450 in treatment naïve subjects with GT-1, GT-2 or GT-3 chronic HCV.

Inclusion Criteria:

• Subject is HCV antibody positive
• Subject is treatment naïve, with no history of exposure (single or multiple dose) to interferon, ribavirin or direct acting antivirals.
• Subject has had a liver biopsy within 3 years or Fibroscan evaluation within 6 months prior to Screening that clearly excludes cirrhosis. If not available prior to Screening, the absence of cirrhosis must be confirmed prior to subject enrollment using either Fibroscan or Fibrosure®.
• Subject is negative for hepatitis A (HAV), hepatitis B (HBV), and human immunodeficiency virus (HIV).

Exclusion Criteria:

• Subject has prior histological evidence of cirrhosis or current clinical evidence of cirrhosis in the opinion of the investigator.
• Subject has a history or evidence of non-hepatitis C chronic liver disease.
• Subject has an estimated creatinine clearance of <80 ml/min if 18-60 years of age, inclusive; or <70 ml/min if >60 years of age, calculated using the Cockcroft-Gault equation.