Ph 3 ADI-PEG 20 Versus Placebo in Subjects With Advanced Hepatocellular Carcinoma Who Have Failed Prior Systemic Therapy

Inclusion Criteria: * Prior diagnosis of HCC confirmed histologically. * Prior treatment with at least 1 systemic agent, with documented progressive disease after systemic agent(s), or adverse event(s)associated with prior systemic agent(s) that resulted in discontinuance of that agent(s). * Cirrhotic status of Child-Pugh grade B7. * Expected survival of at least 3 months. * Adequate hematologic, hepatic, and renal function. Exclusion Criteria: * Candidate for potential curative therapies (i.e., resection or transplantation) or loco-regional approaches (i.e., ablation, embolization). * Significant cardiac disease. * Serious infection requiring treatment with systemically administered antibiotics. * Pregnancy or lactation. * Expected non-compliance. * Uncontrolled intercurrent illness, or psychiatric illness or social situations that would limit compliance with study requirements. * Subjects who have had any anticancer treatment within 2 weeks prior to entering the study. * Subjects who have not fully recovered from toxicities associated with previous HCC loco-regional or systemic therapies. * Subjects with history of another primary cancer, with the exception of: a) curatively resected non-melanoma skin cancer; b) curatively treated cervical carcinoma in situ; or c) other primary solid tumor with no known active disease present in the opinion of the investigator will not affect patient outcome in the setting of current HCC diagnosis. * Allergy to pegylated products. * Bleeding esophageal or gastric varices within the prior three months, except if banded or treated. * Subjects known to be HIV positive. * Uncontrolled ascites (defined as not easily controlled with diuretic treatment). * Having received any blood transfusion, blood component preparation, erythropoietin, albumin preparation, or granulocyte colony stimulating factors (G-CSF) within 7 days prior to screening laboratories or after screening laboratories have been obtained until first dose of study drug or placebo. * Use of traditional medicines approved by local authorities, including but not limited to Chinese herbs within 14 days of first dose of study drug or placebo. * ECOG performance status \> 2. * Prior allograft,including liver transplant.