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

Key Who May Qualify: - 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. - your organs (liver, kidneys, etc.) are working well enough based on blood tests - 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 Who Should NOT Join This Trial: - 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. Always talk to your doctor about whether this trial is right for you.