Tislelizumab Consolidation After Liver-Directed Therapy for Hepatocellular Carcinoma

Safety as assessed by number of participants experiencing adverse events

Number of participants experiencing adverse events grade three or higher, as defined by Common Terminology Criteria for Adverse Events version 5.0 (NCI-CTCAE v5.0). Severity is a measure of intensity (eg, grade of a specific AE, mild \[Grade 1\], moderate \[Grade 2\], severe \[Grade 3\], or life-threatening \[Grade 4\]), whereas seriousness is classified by the criteria based on the regulatory definitions. Seriousness serves as the guide for defining regulatory reporting obligations from the Investigator Sponsor to applicable regulatory authorities as described in CTCAE version 5.0.

Response and progression will be evaluated in this trial using the international criteria proposed by the Response Evaluation Criteria in Solid Tumors (RECIST) Committee (v1.1).

Changes in only the largest diameter (uni dimensional measurement) of the tumor lesions are used in the RECIST criteria. Measurable Disease: Tumor lesions: Must be accurately measured in at least 1 dimension (longest diameter in the plane of measurement is to be recorded) with a minimum size of: * 10 mm by CT scan (irrespective of scanner type) and MRI (no less than double the slice thickness and a minimum of 10 mm) * 10 mm caliper measurement by clinical exam (when superficial) * 20 mm by chest X ray (if clearly defined and surrounded by aerated lung) Malignant lymph nodes: To be considered pathologically enlarged and measurable, a lymph node must be ≥ 15 mm in short axis when assessed by CT scan (CT scan slice thickness recommended to be no greater than 5 mm). At baseline and in follow up, only the short axis will be measured and followed.