Inclusion Criteria:

          1. Male or female subjects

          2. 18 years and older (Japan-20 years and older)

          3. Confirmed HCC based on histopathological findings from tumor tissues. Advanced HCC
             with diagnosis confirmed pathologically or with noninvasive methods.

          4. Immunotherapy-naïve

          5. Have either progressed on, are intolerant to, or refused treatment with sorafenib or
             another approved TKI. For arm 5 only: Have not received any prior systemic therapy for
             HCC.

        Exclusion Criteria:

          1. Prior exposure to immune-mediated therapy

          2. Hepatic encephalopathy within past 12 months or requirement for medications to prevent
             or control encephalopathy

          3. GI Bleeding (eg, esophageal varices or ulcer bleeding) within 12 months

          4. Ascites requiring non-pharmacologic intervention (eg, paracentesis) to maintain
             symptomatic control, within 6 months prior to the first scheduled dose.

          5. Main portal vein thrombosis (Vp4) as documented on imaging

          6. Any concurrent chemotherapy, immunotherapy, or biologic or hormonal therapy for cancer
             treatment

          7. Active or prior documented autoimmune or inflammatory disease with some exceptions

          8. Current or prior use of immunosuppressive medication within 14 days with some
             exceptions