BGB-15025 Alone and in Combination With Anti-PD-1 Monoclonal Antibody Tislelizumab in Participants With Advanced Solid Tumors

Key Inclusion Criteria:

1. Phase 1a (dose escalation): Participants with histologically or cytologicallyconfirmed advanced, metastatic, and unresectable solid tumors who have previouslyreceived standard systemic therapy or for whom treatment is not available, nottolerated or refused, and who have not received prior therapy targeting HPK1

2. Phase 1b (dose expansion): Participant with histologically or cytologicallyconfirmed advanced, metastatic, and unresectable solid tumors, including non-smallcell lung cancer, esophageal cancer or gastric/Gastroesophageal junction cancer (other solid tumors may be included) who have progressed following systemicanticancer therapies or have no prior systemic treatment for advanced disease

3. At least 1 measurable lesion as defined per RECIST 1.1.

4. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 1

5. Adequate organ function as indicated by the following laboratory values up to firstdose of study treatment: Hemoglobin≥ 90 g/L, Absolute neutrophil count ≥ 1.5 x 109/L , Serum total bilirubin ≤ 1.5 x ULN (< 3 x ULN for participants with Gilbertsyndrome ), AST and ALT≤ 2.5 x ULN

Key Exclusion Criteria:

1. Active leptomeningeal disease or uncontrolled and untreated brain metastasis.

2. Active autoimmune diseases or history of autoimmune diseases that may relapse

3. Any active malignancy ≤ 2 years before the first dose of study treatment except forthe specific cancer under investigation in this study and any locally recurringcancer that has been treated with curative intent

4. Any condition that required systemic treatment with either corticosteroids (> 10 mgdaily of prednisone or equivalent) or other immunosuppressive medication ≤ 14 daysbefore the first dose of study treatment

5. History of interstitial lung disease, noninfectious pneumonitis, or uncontrolledlung diseases including but not limited to pulmonary fibrosis, acute lung diseases,etc.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.