A Study of BG-C477 in Participants With Advanced Solid Tumors

Inclusion Criteria: * Participants must sign the informed consent form (ICF) and be capable of giving written informed consent * Participants must consent to provide an archival tumor tissue sample or a fresh baseline biopsy * Phase 1a (Dose Escalation): Histologically confirmed advanced, metastatic, or unresectable solid tumors, that were previously treated with at least 2 lines of standard systemic therapy or for whom no standard treatment is available in the medical judgment of the investigator * Phase 1b (Dose Expansion) Part A: Histologically confirmed advanced or metastatic select solid tumors that were previously treated with and progressed from at least 1 line of standard systemic therapy * Phase 1b (Dose Expansion) Part B: Histologically confirmed advanced or metastatic select solid tumors who have previously received 0 or 1 line of systemic therapy for advanced disease * ≥ 1 measurable lesion as assessed by RECIST v1.1 * Stable Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 1 * Adequate organ function * Female participants of childbearing potential must be willing to use a highly effective method of birth control and refrain from egg donation for the duration of the study and for ≥ 8 months after the last dose of BG-C477, for ≥ 6 months after the last dose of chemotherapy, and for ≥ 4 months after the last dose of tislelizumab,whichever comes later * Nonsterile male participants must be willing to use a highly effective method of birth control an…