Background: To date, chemotherapy remains the only effective treatment of unresectable pancreatic adenocarcinoma. In the last few years, the interest in the use of immunological anticancer strategies is greatly increased. AGIG is a novel chemo-immunotherapy regimen that combines nab-paclitaxel + gemcitabine chemotherapy with sequential recombinant interleukin-2 and granulocyte-macrophage colony stimulating factor (GM-CSF) therapy. We conducted a single-arm prospective phase II study to determine the efficacy and safety of the first-line treatment of advanced pancreatic cancer with AGIG regimen. Methods: Nab-paclitaxel (120 mg/m²) and gemcitabine (1000 mg/m²) were administered intravenously to all patients on days 1 and 8 triweekly, interleukin-2 and GM-CSF (100 µg) were administered subcutaneously on days 3-5 after chemotherapy. The primary end point was ORR by the Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary end points included safety profile, progression-free survival (PFS), overall survival (OS). Patients’ conditions and the efficacy and safety were assessed every 4 cycles. Results: Between 11/2018 and 01/2020, 64 patients were enrolled. In the 64 evaluable patients, the ORR and DCR were 43.75% and 76.6%, respectively. The median follow-up time was 12.1 (range 7.1–22.4) months, the median PFS was 5.7 (range 1.63–15.8) months, and the median OS was 14.2 (range 2.9–22.0) months. The most common adverse event was fever (75%). The incidence of grade 3/4 neutropenia was 4.69%. In subgroup analyses, we found that eosinophil count in the blood elevated three times higher than baseline level predicted a longer survival. Conclusions: The AGIG Chemo-immunotherapy regimen has presented encouraging ORR, OS, and manageable toxicities as first-line therapy for advanced pancreatic cancer. This regimen may be a novel reliable therapeutic option for patients with preserved performance status. The improvement of treatment efficiency may be related to the activation of non-specific immune response. Clinical trial information: NCT0376867. Research Sponsor: The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School.