- Arm B: Patients receive low-dose cyclophosphamide IV on day 0 and GVAX pancreatic cancer vaccine ID on day 1. Patients undergo pancreaticoduodenectomy on day 15. Approximately 6-10 weeks after surgery, patients receive low-dose cyclophosphamide IV on day 0 and the vaccine on day 1. Beginning approximately 1 month after vaccination, patients receive standard adjuvant chemoradiotherapy comprising gemcitabine, fluorouracil or capecitabine, and radiotherapy over 26-28 weeks. Beginning approximately 4-8 weeks after the completion of chemoradiotherapy, patients receive low-dose cyclophosphamide IV on day 0 and the vaccine on day 1. Treatment with cyclophosphamide and the vaccine repeats every 28 days for 4 courses.