A Multicenter, Open-Label, Phase 1a/b First-in-Human Study to Investigate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Antitumor Activity of BG-C477 in Patients With Selected Advanced Solid Tumors

This new study will check how safe and helpful a potential anticancer drug called BG-C477 is. This drug will be tested by itself or combined with other anticancer agents. The purpose of this study is to test if BG-C477 is safe and if it works in people with your disease when it is given on its own and in combination with other anticancer agents.

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 or cytologically confirmed advanced, metastatic, or unresectable solid tumors, who 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
• ≥ 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 and for ≥ 6 months after the last dose of chemotherapy, whichever comes later
• Nonsterile male participants must be willing to use a highly effective method of birth control and refrain from sperm donation for the duration of the study and for ≥ 5 months after the last dose of BG-C477, and for ≥ 3 months after chemotherapy, whichever comes later.

Exclusion Criteria:

• Prior treatment with any carcinoembryonic antigen (CEA)-targeted ADCs or ADCs containing topoisomerase 1 (TOP1) inhibitor as payload
• History of severe allergic reactions, severe reaction to infusion, or hypersensitivity to the active ingredient and excipients of the study drug(s) or protein-based therapeutics
• Active leptomeningeal disease or uncontrolled, untreated brain metastasis
• Any malignancy ≤ 2 years before the first dose of study drug(s) except for the specific cancer under investigation in this study and any locally recurring cancer that has been treated curatively (eg, resected basal or squamous cell skin cancer, superficial bladder cancer, carcinoma in situ of the cervix or breast)