Exploratory Platform Trial to Evaluate Immunotherapy Combinations With Chemotherapy for the Treatment of Patients With Previously Untreated Metastatic Pancreatic Adenocarcinoma

Core Inclusion Criteria 1. Participant has histologically or cytologically documented diagnosis of pancreatic adenocarcinoma with metastatic disease. Participants with locally advanced disease are not eligible. a. Participants with recurrent locally advanced disease are eligible, provided: i. the last dose of chemotherapy and/or radiotherapy occurred \> 4 months prior to the first dose of study intervention, and; ii. no systemic or radiotherapy has been administered in the metastatic setting. 2. Participant must have measurable disease by RECIST v1.1. 3. Participant must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 4. A baseline tumor tissue sample is mandatory for enrollment. If archival tumor tissue is not available, then a fresh tumor biopsy must be provided. 5. Participant must be age 18 years or older. 6. Participant must have adequate organ function. Core Exclusion Criteria 1. Participant must not have received any prior treatment, including chemotherapy, biological therapy, or targeted therapy for mPDAC, with the following exceptions and notes: 1. Participants who have received prior neoadjuvant or adjuvant therapy for pancreatic adenocarcinoma are eligible if neoadjuvant and adjuvant therapy (including chemotherapy and/or radiotherapy) was completed more than 4 months before the start of study intervention. 2. Prior surgical resection is permitted. 3. Participants who have received treatment with any other enadenotucirev-based therapy or anti-CD40 antibody at any time are not eligible for the study (cohort C only). 2. Prior malignancy active within the previous 2 years except for locally curable cancers that have been apparently cured, such as basal or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the prostate, cervix, or breast. 3. Participants with an active, known or suspected autoimmune disease. Participants with: type I diabetes mellitus; hypothyroidism only requiring hormone replacement; a history of Hashimoto syndrome, within 3 years of the first dose of study intervention, which resolved to hypothyroidism alone; skin disorders (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment; or conditions not expected to recur in the absence of an external trigger are permitted to enroll.