Inclusion Criteria:
All Subjects
* If female, subject must be either postmenopausal for at least 2 years or surgically sterile (bilateral tubal ligation, bilateral oophorectomy or hysterectomy).
* Females must have negative results for pregnancy test performed:
* At Screening on a urine specimen obtained within 28 days prior to initial study drug administration, and
* On a serum sample obtained on Study Day -1 of Period 1.
* Males must be surgically sterile or practicing at least one of the following methods of birth control (sperm donation within the study period is not allowed):
* Abstinence
* Partner(s) using an Intrauterine Device (IUD)
* Partner(s) using oral, injected, or implanted methods of hormonal contraceptives
* Subject and/or partner(s) using double-barrier method.
Subjects with Normal Hepatic Function
In addition to the inclusion criteria above for all subjects, the following criteria must be met for subjects with normal hepatic function enrolled in Group IV:
* Judged to be in general good health based upon the results of a medical history, physical examination, laboratory profile (including liver function parameters within the limits of normal) and 12-lead electrocardiogram (ECG).
* Negative hepatitis B surface antigen (HBsAg) and hepatitis C virus antibody (HCV Ab) test results.
* Body Mass Index (BMI) is ≥ 18 to \< 38 kg/m2, inclusive.
Subjects with Hepatic Impairment
In addition to the inclusion criteria for all subjects, the following criteria must be met for all subjects with hepatic impairment enrolled in Groups I, II and III:
* Judged to be in stable condition and acceptable for study participation based upon the results of a medical history, physical examination, laboratory profile and ECG.
* BMI is ≥ 18 to \< 38 kg/m2, inclusive, for subjects with hepatic impairment without ascites or subjects with subclinical ascites detected only by ultrasound or other imaging. For subjects with hepatic impairment and clinically significant ascites, BMI is permitted in the range between ≥ 18 to \< 40 kg/m2, inclusive.
* Child-Pugh classification of Categories A (mild), B (moderate), or C (severe).
* Medical history of chronic liver disease including and not limited to chronic hepatitis B, history of alcoholic liver disease and chronic hepatitis C.
* Presence of clinically significant hepatic impairment as indicated by either:
1. Evidence of liver cirrhosis OR
2. Medical history of at least one of the following criteria:
* Clinical diagnosis of liver disease
* Total bilirubin, \> 2 mg/dl, with indirect/direct ratio \< 1 or prolonged prothrombin time elevation \> 1.7 or an albumin value below the lower limit of the laboratory reference range and excluding non-hepatic causes of the previous laboratory abnormalities.
Exclusion Criteria:
- History of significant sensitivity to any drug.
* Pregnant or breastfeeding female.
* Recent (6-month) history of drug or alcohol abuse.
* Positive test result for hepatitis A virus immunoglobulin M (HAV-IgM) or human immunodeficiency virus antibody (HIV Ab). Negative HIV status will be confirmed at Screening and the results will be maintained confidentially by the study site.
* Detectable HCV RNA.
