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.