This is a multi-center,open-label study to evaluate the efficacy and safety of anti-PD-1 antibody HX008 plus bevacizumab or lenvatinib in the first-line treatment of patients with unresectable hepatocellular carcinoma.

Inclusion Criteria:

• Understood and signed an informed consent form.
• Age ≥ 18 and ≤ 75 years old, male or female.
• Has histologically- or cytologically-confirmed diagnosis of unresectable hepatocellular carcinoma.
• Has Barcelona Clinic Liver Cancer (BCLC) Stage C disease, or BCLC Stage B disease not amenable to locoregional therapy or refractory to locoregional therapy, and not amenable to a curative treatment approach.
• Child-Pugh class A and B (≤7 points).
• Has not received any systematic treatment for HCC.
• Has a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Score.
• Life expectancy ≥ 3 months.
• Has at least one measurable disease based on RECIST 1.1.
• Has adequate organ function as defined in the protocol.
• Female participants of childbearing potential should have a negative pregnancy within 7 days before the randomization. Male and female participants should agree to use an adequate method of contraception during the experiment and 1 year after the last administration of the test drugs.

Exclusion Criteria:

• Histologically or cytologically documented fibrolamellar hepatocellular carcinoma, sarcoma-like hepatocellular carcinoma, cholangiocarcinoma, etc.
• Diagnosed additional malignancy within 3 years prior to the first dose of trial, with the exception of curatively treated basal cell carcinoma of the skin, squamous cell carcinoma of the skin,curatively resected in situ cervical or non-muscle invasive bladder cancers.
• Has received locoregional therapy or surgery within 4 weeks prior to the first dose of trial treatment; received palliative radiotherapy or herbal medicine within 2 weeks prior to the first dose of trial treatment;
• Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis.
• HBV-DNA>2000 IU/mL or 10^4 copy/mL; HCV-RNA>10^3 copy/mL.
• Has had esophageal or gastric variceal bleeding within the last 6 months.
• Portal vein tumor thrombus (PVTT) involves both the main trunk and contralateral branch or upper mesenteric vein. Inferior vena cava tumor thrombus.
• Other obvious hemorrhagic tendency or evidence on important coagulation disorder.
• Serious cardiovascular and cerebrovascular diseases.
• Inability to swallow tablets, malabsorption syndrome or any other condition that affects gastrointestinal absorption.
• Serious, uncured wound, active ulcer or untreated bone fracture.
• Uncontrolled pericardial effusion, uncontrolled pleural effusion or clinically obvious moderate peritoneal effusion at screening.
• Has active autoimmune disease that has required systemic treatment in past 2 years.
• Has received a major surgery within 4 weeks prior to the first dose of tiral treatment.
• Has received system treatment with corticosteroids (dose >10mg/day prednison or other therapeutic hormones) within 2 weeks prior to the first dose of trial treatment.
• Has a history of non-infectious pneumonitis that required steroids or has current pneumonitis.
• Has known active tuberculosis (Bacillus tuberculosis)
• Has a history of testing positive for human immunodeficiency virus (HIV), or known acquired immunodeficiency syndrome (AIDS), or stem cell transplantation or organ transplantation.
• Co-infection of HBV and HCV.
• Any serious acute and chronic infection within 4 weeks prior to the first dose of trial treatment, or infection requiring systemic antibacterial, antifungal or antiviral therapy within 2 weeks prior to the first dose of trial treatment.
• Has participated in other anticancer drug clinical trials within 4 weeks.
• Has received a live vaccine within 30 days prior to the first dose of trial treatment.
• According to the judgement of the investigators, there are other factors that may lead to the termination of the study.