Inclusion Criteria:

- Histologically confirmed hepatocellular carcinoma

- Confirmed by needle aspirate, biopsy, or prior surgical resection specimen

- Clinically confirmed hepatocellular carcinoma defined as follows:

- Cirrhosis or chronic hepatitis B or C virus infection, with 1 or more
hypervascular liver masses more than 2 cm

- Alpha-fetoprotein (AFP) greater than 400 ng/mL OR greater than 3 times normal
and doubling in value during the past 3 months

- Deemed unresectable

- Prior surgical resection allowed

- Recurrence after hepatic resection or other procedure allowed

- Tumor that extends into branches of the portal or hepatic veins allowed

- No tumor invading the main portal vein (portal trunk) or inferior vena cava

- No tumor occupying more than 50% of the liver volume

- Enlargement/involvement of regional (porta-hepatis) lymph nodes allowed

- At least 1 unidimensionally measurable lesion at least 20 mm

- No poorly defined lesions

- No vague hypervascular patches

- Child-Pugh class A or compensated Child-Pugh class B liver dysfunction

- No Child-Pugh class C or uncompensated class B indicated by active
encephalopathy, persistent ascites, or prothrombin time greater than 1.5 times
normal

- Prior ascites allowed if manageable with diuretics alone

- No repeated paracentesis (more than 1 per month)

- No extrahepatic metastasis

- No documented brain metastases

- No history or clinical evidence of CNS disease (e.g., primary brain tumor, seizures
uncontrolled with standard medical therapy, or history of stroke)

- Performance status - ECOG 0-2

- Absolute neutrophil count greater than 1,500/mm^3

- Hemoglobin at least 8 g/dL

- Platelet count at least 75,000/mm^3

- No prior serious bleeding event (unrelated to liver disease)

- No bleeding diathesis

- No coagulopathy

- Bilirubin no greater than 3 mg/dL

- Transaminases less than 5 times upper limit of normal (ULN)

- Albumin at least 2.5 mg/dL

- PTT less than 4 seconds above ULN

- INR less than 1.5 (for patients receiving warfarin)

- Creatinine less than 1.5 g/dL

- Urine protein less than 500 mg/24hrs*

- No thromboembolic event within the past 12 months including the following:

- Stroke

- Myocardial infarction

- Transient ischemic attack

- Angina

- No clinically significant cardiovascular disease including the following:

- Uncontrolled hypertension

- Unstable angina

- Congestive heart failure (New York Heart Association grade II-IV)

- Serious cardiac arrhythmia requiring medication

- Grade II or greater peripheral vascular disease within the past year

- No deep vein thrombosis within the past year

- No pulmonary embolus within the past year

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No active infection requiring parenteral antibiotics

- No serious non-healing wound/ulcer or bone fracture

- No variceal bleeding within the past 6 months

- Prior esophageal varices allowed provided the following criteria are met:

- Specific therapy (i.e., banding or sclerotherapy) has been received

- No bleeding within the past 6 months

- Varices remaining obliterated, minimal, or grade 1 (involving less than 33%
of luminal diameter)* by re-endoscopy within the past 4 weeks

- No malignancy within the past 5 years except localized nonmelanoma skin cancer

- No ongoing psychiatric or social situation that would preclude study compliance

- No known hypersensitivity to Chinese hamster ovary cell products

- No known hypersensitivity to other recombinant human antibodies

- No more than 1 prior biologic therapy

- No concurrent interferon

- No concurrent interleukin-2

- No more than 1 prior antineoplastic chemotherapy

- At least 4 weeks since prior invasive surgery, including open biopsy

- At least 2 weeks since prior needle biopsy (core or fine-needle aspirate)

- No concurrent hepatic transplant

- At least 4 weeks since prior anticancer therapy

- No concurrent platelet-stimulating factors (e.g., oprelvekin)

- No concurrent full-dose anticoagulants or thrombolytic agents (except as required to
maintain patency of pre-existing, permanent indwelling IV catheters)

- No chronic daily antiplatelet drugs (e.g., aspirin doses of 325 mg/day or higher or
non-steroidal anti-inflammatory drugs)