A Study of Raludotatug Deruxtecan (R-DXd) in People With Gastrointestinal Cancers (MK-5909-005)

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

• Has one of the following cancers:

• Unresectable or metastatic pancreatic ductal adenocarcinoma (PDAC)

• Unresectable or metastatic adenocarcinoma of the biliary tract [intra- orextrahepatic holangiocarcinoma (CCA) or gallbladder cancer (GBC)]

• Unresectable or metastatic colorectal adenocarcinoma

• Unresectable or metastatic gastric adenocarcinoma

• Gastroesophageal junction adenocarcinoma (GEJAC)

• Esophageal adenocarcinoma (EAC)

• Has received prior therapy for the cancer

• Has a life expectancy of at least 3 months

• If human immunodeficiency virus (HIV) infected, must have well controlled HIV onantiretroviral therapy (ART)

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

• Has a history of (noninfectious) interstitial lung disease (ILD)/pneumonitis thatrequired steroids or has current ILD/pneumonitis, and/or suspected ILD/pneumonitis

• Has clinically severe pulmonary compromise resulting from intercurrent pulmonaryillnesses

• Has uncontrolled or significant cardiovascular disease

• Has a known additional malignancy that is progressing or has required activetreatment within the past 3 years

• Has known active central nervous system (CNS) metastases and/or carcinomatousmeningitis

• Active autoimmune disease that has required systemic treatment in the past 2 years

• Has not adequately recovered from major surgery or has ongoing surgicalcomplications

• HIV-infected participants with a history of Kaposi's sarcoma and/or MulticentricCastleman's Disease