A Study to Evaluate the Safety, Tolerability, and Preliminary Efficacy of BRII-5395 in Combination With Sintilimab and Bevacizumab in Advanced Hepatitis B Virus Related Hepatocellular Carcinoma

Inclusion Criteria: 1. Diagnosis of locally advanced or metastatic HCC that is deemed unsuitable for surgical resection or transplant. 2. BCLC stages Intermediate (B) or Advanced (C). 3. Failed at least first-line systemic therapy, including ICIs; and disease is not amenable to curative surgical and/or locoregional therapies. 4. Adequate bone marrow and organ function status. 5. Life expectancy \> 3 months. 6. HBsAg \> 0.05 IU/mL at screening. Exclusion Criteria: 1. Any systemic anticancer therapy within specified period prior to the first dose of study treatment. 2. Any localized anticancer therapy within specified period prior to the first dose of study treatment. 3. History of anaphylactic hypersensitivity prior to the first dose of study treatment. 4. Known hypersensitivity to polyethylene glycol or any component of sintilimab or bevacizumab formulation, or any contraindications to sintilimab or bevacizumab. 5. Presence of cancer or metastasis in the central nervous system with clinical symptoms. 6. Remaining ≥ NCI-CTCAE grade 2 toxicities from previous anticancer therapy, unless otherwise specified. 7. Current or past history of infection with HIV, HCV, or active tuberculosis.