AGEN1423 and Botensilimab w/ or w/o Chemo in PDAC

The research study procedures include screening for eligibility and study treatment including evaluations and follow up visits. * Participants will receive study treatment for about 2 years and will be followed for 1 year. If the combination is considered to be safe and tolerable, and objective response is achieved in at least 2 patients, the study will proceed to Cohort 2. * This research study involves immunotherapy. The names of the study drugs involved in this study are: * AGEN1423 * Botensilimab It is expected that about 24 people will take part in this part of this research This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational drug to learn whether the drug works in treating a specific disease. "Investigational" means that the drug is being studied. The U.S. Food and Drug Administration (FDA) has not approved AGEN1423 as a treatment for any disease. The U.S. Food and Drug Administration (FDA) has not approved Botensilimab as a treatment for any disease. Agenus, a pharmaceutical company, is supporting this research study by providing funding and study drug for the research study.