A Study of ZW191 in Participants With Solid Tumors

Inclusion Criteria:

• Pathologically or cytologically confirmed diagnosis of cancers with evidence oflocally advanced (unresectable), recurrent and/or metastatic disease.

• Measurable disease per RECIST v1.1.

• Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1.

• Adequate cardiac function: Cardiac left ventricular function, as defined by leftventricular ejection fraction (LVEF) ≥ 50% as determined by either echocardiogram (ECHO) or multigated acquisition scan (MUGA).

• Other adequate organ function.

Exclusion Criteria:

• Known additional malignancy that is progressing or requires active treatment or mayinterfere with study endpoints.

• Has received prior Topoisomerase I inhibitor(TOPO1i) antibody drug conjugatetreatment, regardless of washout period.

• Acute or chronic uncontrolled renal disease, pancreatitis, or liver disease.

• Severe chronic or active infections (including known active SARS-CoV-2 infection)requiring systemic therapy, including antibacterial, antifungal, or antiviraltherapy.