This expanded access program provides a potential pathway for eligible patients with resected pancreatic ductal adenocarcinoma (PDAC) to receive PCNAT-01, an investigational, personalized tumor neoantigen peptide vaccine, outside of the ongoing clinical trial when participation in the clinical trial is not possible or feasible. PCNAT-01 is intended for use in disease-free patients following surgical resection and completion of standard adjuvant therapy to reduce the risk of recurrence. Access is subject to Sponsor review, regulatory authorization, institutional review board approval, physician oversight, successful patient-specific vaccine manufacture, and confirmation that treatment under expanded access will not interfere with the ongoing clinical development program.