RecruitingPhase 1Drug trialA First-in-Human (FIH) Study of BG-C137, an Anti-Fibroblast Growth Factor Receptor 2b (FGFR2b) Antibody Drug Conjugate, in Participants With Advanced Solid TumorsThe purpose of this study is to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and preliminary antitumor activity of BG-C137 alone and in combination with anticancer agents in participants with advanced solid tumors. The study will be conducted in two phases: Phase 1a (Monotherapy Dose Escalation, and Safety Expansion; Combination Dose Confirmation and Safety Expansion) and Phase 1b (Dose Expansion).