A Study of T-DXd as Monotherapy or in Combination With Anti-cancer Agents in Patients With Selected HER2-expressing Tumors

Inclusion Criteria: * At least 18 years of age. * Locally advanced, unresectable, or metastatic solid tumors based on most recent imaging. * HER2 expression. * ECOG performance status of 0-1. * Must provide an adequate FFPE tumor sample to centrally determine HER2 status and other correlatives. * Has measurable target disease assessed by the investigator based on RECIST 1.1. * Adequate organ function and bone marrow within 14 days before enrollment. * Contraceptive use by males or females should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. * Capable of giving signed informed consent. * Provision of signed and dated written ICF prior to mandatory study-specific procedures, sampling, or analyses. * Evidence of post-menopausal status or negative serum pregnancy test for females of childbearing potential who are sexually active with a non-sterilized male partner. Exclusion Criteria: * Primary diagnosis of adenocarcinoma of the breast, adenocarcinoma of the gastric body or gastroesophageal junction. * Has substance abuse or any other medical conditions that may interfere with the patient's participation in the clinical study or evaluation of the clinical study results. * A pleural effusion, ascites or pericardial effusion that requires drainage, peritoneal shunt, or Cell-free and concentrated ascites reinfusion therapy. * History of another primary malignancy except for malignancy treated with curative …