A Study to Evaluate the Efficacy and Safety of Ifinatamab Deruxtecan (I-DXd) in Subjects With Recurrent or Metastatic Solid Tumors (IDeate-PanTumor02)

Participants must meet all of the following criteria to be included in the study: Common Inclusion Criteria for All Participants 1. Participants must consent to provide a pretreatment tumor sample which has not been previously irradiated. Fresh biopsies are strongly preferred, however, if a fresh pretreatment biopsy is not feasible or the procedure is unsuccessful, an appropriate archival sample must be provided. The most recent archival sample obtained up to 5 years prior to consent is acceptable. 2. Participants ages ≥18 years (follow local regulatory requirements if the legal age of consent for study participation is \>18 years). 3. At least 1 measurable lesion on computed tomography (CT) or magnetic resonance imaging (MRI) according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1), as assessed by the investigator. 4. Documentation of radiological disease progression on or after the previous standard-of-care regimen. For NEC participants for which the standard therapy does not exist OR for which the standard therapy is not appropriate by the investigator: presence of advanced/metastatic disease without previous regimen is acceptable. 5. Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. Additional Inclusion Criteria for EC Participants 1. Pathologically or cytologically documented EC of any histological carcinoma subtype or endometrial carcinosarcoma, irrespective of microsatellite instability or mismatch repair status. 2. Relapse or progression after a platinum-containing systemic treatment and an immune checkpoint inhibitor (ICI)-containing regimen (combined or sequential). Participants with actionable target tumor mutation should have been previously treated with targeted therapy, with a maximum of 3 prior lines of therapy for endometrial carcinoma or carcinosarcoma. Neoadjuvant/adjuvant therapy may count as 1 line of therapy if the subject progressed within 6 months after completion of therapy. Additional Inclusion Criteria for HNSCC Participants 1. Pathologically or cytologically documented unresectable or metastatic squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx, excluding nasopharynx, nasal cavity and paranasal sinuses, and unknown primary. 2. Has disease progression after platinum-based and ICI treatment, whether administered in combination or separately. Participants with actionable target tumor mutation should have been previously treated with targeted therapy, with a maximum of 2 prior therapy lines for unresectable or metastatic HNSCC. 3. Participants without radiographic evidence of major blood vessel invasion/infiltration or tumor demonstrating a greater than (\>)90-degree abutment or encasement of a major blood vessel. 4. Participants with no prior history of Grade greater than or equal to (≥)3 bleeding as per the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0 within 28 days prior to the start of study drug related to the current head and neck cancer may be included in the study. 5. Documented p16 status for oropharyngeal cancer (historical results are acceptable if available). Additional Inclusion Criterion for PDAC Participants 1\. Pathologically or cytologically documented unresectable or metastatic pancreatic adenocarcinoma that has relapsed or progressed after 1 prior line of gemcitabine-based systemic therapy in the locally advanced/metastatic setting or after 2 lines of therapy if the participant has actionable target tumor mutation and has been previously treated with targeted therapy. a. No prior treatment with topoisomerase I inhibitors, such as irinotecan or topotecan. Additional Inclusion Criteria for CRC Participants 1. Pathologically or cytologically documented unresectable or metastatic CRC with microsatellite stable status (MSS). 2. Relapse or progression after 1 prior line of systemic therapy including a fluoropyrimidine plus oxaliplatin with or without anti-vascular endothelial growth factor (VEGF) monoclonal antibody (mAb) or anti-epidermal growth factor receptor mAb therapy, as clinically indicated, or relapse or progression after 2 lines of therapy if the subject has received targeted therapy. Note: Prior adjuvant/neoadjuvant systemic cytotoxic chemotherapy will count as 1 line of prior systemic therapy if there is documented disease progression during therapy or within 6 months of chemotherapy completion. 3. No prior treatment with topoisomerase I inhibitors, such as irinotecan or topotecan. Additional Inclusion Criteria for HCC Participants 1. Pathologically or cytologically documented unresectable or metastatic HCC (fibrolamellar and mixed hepatocellular/cholangiocarcinoma subtypes are not eligible) or noninvasive diagnosis of HCC as per the American Association for the Study of Liver Diseases (AASLD) criteria in participants with a confirmed diagnosis of cirrhosis. 2. Relapse or progression after 1 prior line of an ICI-containing regimen (combination or monotherapy) in the locally advanced/metastatic setting, or relapse or progression after 2 lines of therapy if the participant has an actionable target tumor mutation and has been treated with targeted therapy. 3. Barcelona Clinic Liver Cancer (BCLC) Stage B or C. 4. Liver function status should be Child-Pugh (CP) Class A. 5. Albumin-Bilirubin (ALBI) Grade 1 within 7 days prior to the first dose of study drug. 6. Participants with large esophageal varices at risk of bleeding must be treated with conventional medical intervention: beta blockers or endoscopic treatment. Additional Inclusion Criteria for Ad-eso/GEJ/Gastric Participants 1. Pathologically or cytologically documented unresectable or metastatic Ad-eso/GEJ/Gastric that has relapsed or progressed after 1 prior line of systemic therapy in the locally advanced/metastatic setting. a. Participants with PD-(L)1+ or MSI-H/dMMR should receive ICI treatment if ICIs are standard of care in the count