Epacadostat, Pembrolizumab, and CRS-207, With or Without CY/GVAX Pancreas in Patients With Metastatic Pancreas Cancer

Inclusion Criteria (abbreviated): * Documented adenocarcinoma of the pancreas * Have disease progression after prior chemotherapy for metastatic pancreas cancer (or adjuvant or neoadjuvant if progression occurred within 6 months of completing this regimen) * Presence of at least one measurable lesion * Patient acceptance to have a tumor biopsy of an accessible lesion at 2 time points (baseline and on study) * ECOG performance status of 0 or 1 * Life expectancy of greater than 3 months * Adequate organ and marrow function defined by study-specified laboratory tests Exclusion Criteria (abbreviated): * Brain metastases * Clinical or radiographic ascites (some trace amount may be allowed) * Rapidly progressing disease * Live vaccine within 30 days of study treatment (flu vaccine allowed) * Surgery within 28 days of study treatment (some exceptions for minor procedures) * Use of an investigational agent or device within 28 days of study treatment. * Chemotherapy, radiation, or biological cancer therapy within 14 days of study treatment. * Prior treatment with anti-CTLA-4, anti-PD-1, anti-PD-L1, or anti PD-L2, or with IDO inhibitor. * Use of growth factors within 14 days of study treatment * Use of any systemic steroids within 14 days of study treatment or other immunosuppressive agents within 7 days of study treatment. * Use of more than 2 g/day of acetaminophen * Use of any UGT1A9 inhibitor * Use of warfarin * Use of MAOIs or drugs with significant MAOI activity within the 21 days of screening * History of Seratonin Syndome * Known allergy to both penicillin and sulfa * Known or suspected hypersensitivity to any monoclonal antibody or any study drug component * Have artificial joints or implants that cannot be easily removed or a history of infection associated with an implant * Significant or malignant pleural effusion * New pulmonary embolism, extremity deep venous thromboembolism, or portal vein thrombosis within 2 months of study enrollment * History of autoimmune disease (exceptions for Graves or Hashimoto's disease, vitiligo, and type I diabetes mellitus) * Gastrointestinal condition that may affect drug absorption * Significant heart disease or heart disease requiring antibiotic for prevention of endocarditis * History of abnormal electrocardiogram (ECG) that is deemed meaningful by the investigator * History of (non-infectious) pneumonitis that required steroids, evidence of interstitial lung disease or active, non-infectious pneumonitis * Pulse oximetry of \< 92% on room air or the need for supplemental home oxygen * Infection with HIV, hepatitis B or hepatitis C * Other conditions, including alcohol or drug dependence, intercurrent illness, or lack of sufficient peripheral venous access that would affect the patient's ability to comply with study visits and procedures * Pregnant or breastfeeding women * Unwillingness or inability to follow the study schedule for any reason