Inclusion Criteria:

- Child-Pugh Class A

- BCLC Stage B or C

- Measurable Liver Cancer

- ECOG Performance Status of 0, 1, or 2

- Age 18 years or older

Exclusion Criteria:

- Received prior investigational or non-investigational agent to treat hepatocellular
carcinoma

- Previously received mapatumumab and/or sorafenib

- Major surgery within 4 weeks before enrollment

- Minor surgery within 2 weeks before enrollment

- Systemic steroids within 1 week of enrollment

- Hepatic encephalopathy

- History of clinically significant gastrointestinal bleeding

- Gastrointestinal disease resulting in the inability to take oral medication

- History of infection requiring hospitalization or IV antibiotics

- Known brain or spinal cord metastases

- Known HIV infection

- Unstable angina, myocardial infarction, or cerebrovascular accident within 6 months
before enrollment

- Cardiac arrhythmias requiring anti-arrhythmic therapy other than beta blockers or
digoxin

- Uncontrolled hypertension

- Using and unable to discontinue use of CYP3A4 inducers

- Pregnant or breast-feeding women

- Acute or chronic severe renal insufficiency

- Hepatitis B virus DNA levels >2,000IU/mL