This study will assess the pharmacokinetics of AFQ056 in subjects with mild, moderate, severe hepatic impairment compared with healthy control subjects.

Inclusion Criteria:

• Groups 1, 2, 3 and 4 (all subjects)
• Male and female Caucasian subjects
• Group 1, 2 and 3 (subjects with hepatic impairment)
• Subjects must satisfy the criteria for hepatic impairment as evidenced by a Child-Pugh score of A, B or C at screening
• Group 4 (healthy subjects)
• Each healthy subject must match in age (±8 years), gender, weight (±15%) to an individual subject with hepatic impairment in group 1, 2 or 3.

Exclusion Criteria:

• Groups 1, 2, 3 and 4 (all subjects)
• Use of any tobacco products from 1 week prior to cotinine screening assessments until study completion.
• Group 1, 2 and 3 (subjects with hepatic impairment)
• History of drug or alcohol abuse within 3 months prior to screening
• History or presence of any clinically significant disease of any major system organ class including (but not limited to) cardiovascular, metabolic, renal, neurological or psychiatric diseases within 1 month prior to study drug administration except for hepatic impairment or any other disease associated with this underlying condition.
• Any surgical or medical condition other than hepatic impairment which might significantly alter the absorption, distribution, metabolism, or excretion of drugs, or which may jeopardize the safety of the study subject in case of participation in the study.
• History or presence of encephalopathy within 6 months prior screening (except for subjects in Groups 2 and 3).
• Documented presence of a porto-systemic shunt.
• Documented presence of esophagus varices (stage III or IV).
• Group 4 (healthy subjects)
• History or presence of any clinically significant disease of any major system organ class including (but not limited to) cardiovascular, metabolic, renal, neurological or psychiatric diseases.
• Any surgical or medical condition which might significantly alter the absorption, distribution, metabolism, or excretion of drugs, or which may jeopardize the safety of the study subject in case of participation in the study. History of drug or alcohol abuse within 12 months prior to screening, or evidence of such abuse as indicated by the laboratory assays conducted during screening and baseline.
• History or presence of hepatitis B or C and/or positive Hepatitis B surface antigen (HBsAg) or Hepatitis C test result at screening.

Other protocol-defined inclusion/exclusion criteria may apply