This is a phase I, single center, open label, non-randomized, dose-escalation phase I study performed in the ambulatory setting in patients receiving first line chemotherapy for unresectable pancreas cancer with gemcitabine weekly and the investigational agent IMP321. IMP321 will be given at D2 and D16 of a 4-week cycle, for a period of 6 months. The hypothesis of this study is that IMP321 is safe for human administration. Additionally we hypothesize that IMP321 elicits an immunomodulatory effect that is therapeutic in the treatment of pancreas cancer.