Study of Novel Immunomodulators as Monotherapy and in Combination With Anticancer Agents in Participants With Advanced Hepatobiliary Cancer

Inclusion Criteria: * Age ≥18 years at the time of signing the ICF. * Provision of a signed and dated written ICF. * Confirmed locally advanced or metastatic solid tumor specified in substudy based on histopathology. * Adequate organ and bone marrow function. * At least 1 measurable not previously irradiated lesion per RECIST 1.1 * Life expectancy of at least 12 weeks at the time of screening. * Willing and able to provide an adequate tumor sample. Exclusion Criteria: * History of allogeneic organ transplantation. * Active or prior documented autoimmune or inflammatory disorders. * Uncontrolled intercurrent illness. * History of another primary malignancy, leptomeningeal carcinomatosis, and active primary immunodeficiency. * Active infection, brain metastases or spinal cord compression. * Participants co-infected with HBV and hepatitis D virus (HDV). * Previous treatment in the present study. * For substudy 1, history of hepatic encephalopathy within 12 months prior to treatment allocation.