Hepatocellular Carcinoma Study Comparing Vaccinia Virus Based Immunotherapy Plus Sorafenib vs Sorafenib Alone

Inclusion Criteria:

   - Histological/cytological diagnosis of primary HCC

   - Advanced stage HCC (Barcelona Clinic Liver Cancer [BCLC] Stage C or B per American
   Association for the Study of Liver Disease [AASLD] guidelines)

   - At least one measurable viable tumor in the liver, ≥1 cm longest diameter (LD), using
   a dynamic imaging technique (arterial phase of triphasic computerized tomography [CT]
   scan, or dynamic contrast-enhanced magnetic resonance imaging [MRI]), and injectable
   under imaging-guidance (CT and/or ultrasound)

   - Child-Pugh Class A

   - Performance status 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale

   - Adequate hematological, hepatic, and renal function:

   - Additional inclusion criteria exist

Exclusion Criteria:

   - Histological diagnosis of cholangiocarcinoma, hepatocholangiocarcinoma, fibrolamellar
   carcinoma and hepatoblastoma

   - Symptomatic cardiovascular disease, including but not limited to significant coronary
   artery disease (e.g., requiring angioplasty or stenting) or congestive heart failure
   within the preceding 12 months

   - Current or past history of cardiovascular disease (e.g.. past history of myocardial
   infarction, ischemic cardiomyopathy) unless cardiology consultation and clearance has
   been obtained for study participation

   - History of moderate or severe ascites, bleeding esophageal varices, hepatic
   encephalopathy or pleural effusions related to liver insufficiency within 6 months of
   screening

   - Bulky disease patients - tumors encompassing >50% of the liver volume and / or
   inferior vena cava invasion

   - Known significant immunodeficiency due to underlying illness (e.g., HIV/AIDS) and/or
   immune-suppressive medication including high-dose corticosteroids

   - Ongoing severe inflammatory skin condition (as determined by the Investigator)
   requiring medical treatment

   - History of severe eczema (as determined by the Investigator) requiring medical
   treatment

   - Additional exclusion criteria exist