Neoantigen Vaccines in Pancreatic Cancer in the Window Prior to Surgery

This is a randomized phase 1 clinical trial to evaluate the safety of an optimized neoantigen synthetic long peptide (SLP) vaccines in pancreatic cancer patients following neoadjuvant chemotherapy. The neoantigen SLP vaccines will incorporate prioritized neoantigens and will be co-administered with poly-ICLC. Patients will be randomized to one of two arms: Arm 1 (neoantigen vaccine following neoadjuvant chemotherapy and surgery) or Arm 2 (neoantigen vaccine following neoadjuvant chemotherapy in the window prior to surgery). Those who are ineligible for vaccine administration including those whose disease progresses or recurs during neoadjuvant chemo or who are otherwise unable to complete surgical resection but who had a personalized neoantigen vaccine manufactured, or significant progress has been made as determined by treating physician, are permitted to receive vaccine injections on study.