A Study of ZW251 in Participants With Advanced Solid Tumors

Inclusion Criteria: * Pathologically or cytologically confirmed diagnosis of HCC with evidence of locally advanced (unresectable, and ineligible for transplant) and/or metastatic disease. Noninvasive methods may be used to confirm diagnosis * Pathologically or cytologically confirmed diagnosis of squamous cell NSCLC with evidence of locally advanced (unresectable) and/or metastatic disease * Pathologically or cytologically confirmed diagnosis of GCT with evidence of yolk sac and/or choriocarcinoma predominant component and locally advanced (unresectable) and/or metastatic disease * Measurable disease per RECIST v1.1 * Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1 * Liver function status of Child-Pugh Class A (for HCC only) * Adequate organ function Exclusion Criteria: * Known additional malignancy that is progressing or that has required active treatment within the last year * History of hepatic encephalopathy within the past 6 months or requirement for medications to control encephalopathy * Participants with HCC experiencing main portal vein tumor invasion require sponsor approval for enrollment * Known gastrointestinal bleeding within 3 months * Acute or chronic uncontrolled renal disease, pancreatitis, or non-malignant liver disease