A Study of Multiple Immunotherapy-Based Treatment Combinations in Participants With Metastatic Pancreatic Ductal Adenocarcinoma (Morpheus-Pancreatic Cancer)

Inclusion Criteria: * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Histologically or cytologically confirmed metastatic pancreatic ductal adenocarcinoma * For patients in Cohort 1: no prior systemic treatment for PDAC * For patients in Cohort 2: disease progression during administration of either 5-FU- or gemcitabine-based first-line chemotherapy * Life expectancy greater than or equal to 3 months * Availability of a representative tumor specimen that is suitable for determination of programmed death-ligand 1 (PD-L1) and/or additional biomarker status via central testing * Measurable disease (at least one target lesion) according to RECIST v1.1 * Adequate hematologic and end-organ function test results * Tumor accessible for biopsy * For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures, and agreement to refrain from donating eggs, as outlined for each specific treatment arm * For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures, and agreement to refrain from donating sperm, as outlined for each specific treatment arm Exclusion Criteria: * Uncontrolled pleural effusion, pericardial effusion, or ascites requiring drainage procedure (i.e., more than one time per month) * Symptomatic, untreated, or actively progressing central nervous system (CNS) metastases * History of leptomeningeal disease * Active or histor…