A Study of CHS-114 (Tagmokitug) in Combination With Toripalimab and/or Other Treatments in Participants With Advanced Solid Tumors

Key Inclusion Criteria: * At least 1 measurable lesion based on RECIST v1.1 as determined by the Investigator. * Resolved acute effects of any prior therapy to baseline severity or Grade 1 in accordance with National Cancer Institute (NCI)-Common Terminology Criteria for Adverse Events (CTCAE) v5.0, except for adverse events (AEs) not constituting a safety risk per Investigator judgement. Cohort A (2L Gastric, Gastro-esophageal-junction \[GEJ\], Esophageal Adenocarcinoma \[EAC\]) Specific Inclusion Criteria: * Histologically or cytologically documented unresectable, locally advanced or metastatic gastric, GEJ, or esophageal adenocarcinoma that is human epidermal growth factor receptor 2 (HER2) - negative and microsatellite stable (MSS)/proficient mismatch repair (pMMR). * Progressed during or after first line systemic therapy that includes a platinum and fluoropyrimidine doublet with or without anti-programmed death receptor 1 (PD-1)/programmed death ligand 1 (PD-L1)-directed therapy (that is, in the second line setting). * Consent to provide tumor tissue samples (baseline and on-treatment) is required for enrollment. Cohort B (2L Esophageal Squamous Cell Carcinoma \[ESCC\]) - Specific Inclusion Criteria: * Histologically or cytologically documented unresectable, locally advanced or metastatic ESCC. * Progressed during or after first line systemic therapy including a doublet of platinum and fluoropyrimidine or paclitaxel with or without anti-PD-1/PD-L1-directed therapy o…