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~Balstilimab~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 Balstilimab 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.
The goal of this research study is to asses the safety and efficacy of the combination of AGEN1423 and Balstilimab with or without chemotherapies, gemcitabine and nab-paclitaxel, for the treatment of advanced pancreatic ductal adenocarcinoma (PDAC) which has progressed after at least one previous line of cancer therapy.~The names of the study drugs involved in this study are:~AGEN1423~Balstilimab~Participants will receive study treatment for about 2 years and will be followed for 1 year after.