A First-in-Human Study Using BDC-4182 as a Single Agent in Advanced Gastric and Gastroesophageal Cancer

Key Inclusion Criteria:

* Has disease that is measurable by Response Evaluation Criteria in Solid Tumors (RECIST) v.1.1.
* Subjects must have histologically/cytologically confirmed gastric or gastroesophageal cancer that is metastatic (Stage 4) or unresectable (Stage 3).
* Subjects must have received at least 1-2 prior lines of locally available standard therapies or must be intolerant of standard therapies.
* For subjects in escalation: If prior Claudin 18 IHC expression is known, the subject must have some degree of Claudin 18 expression as defined as Positive or have expression ≥ 1% of tumor cells IHC ≥ 2+. Consult with Medical Monitor as needed.
* Adequate organ function
* Agree to have a biopsy prior to enrollment, at acceptable risk in the judgement of the Investigator. If a biopsy is not safely accessible or clinically feasible, an adequate archival tumor sample must be submitted.

Key Exclusion Criteria:

* Known central nervous system (CNS) metastases except for disease that is asymptomatic, clinically stable, and has not required steroids for at least 14 days before starting study treatment.
* Cardiac disease, pulmonary disease, or hepatic disease
* Active infection
* History of inflammatory eye disease
* Residual toxicity from a previous treatment
* Any investigational agent or standard anti-cancer therapies within 28 days before starting study treatment or within 5 estimated elimination half-lives, whichever is shorter.