A Phase II Randomized Study of Gemcitabine and Nab-paclitaxel in Combination With S- 1/LV (GASL) or Oxaliplatin (GAP) as First-line Treatment for Metastatic Pancreatic Cancer

Inclusion Criteria:

• A.Cytology or histology confirmed pancreatic adenocarcinoma with evidence of distantmetastasis.Mixed component of other cell type (eg, adenosquamous, adenocarcinomawith neuroendocrine differentiation) is eligible but should notify PI beforeregistration.

• B.No history of prior chemotherapy for pancreatic cancer, except adjuvantchemotherapy that completed at least 6 months before documentation of recurrence byimaging study.

• C.Patients with prior radiotherapy are eligible if there are other measurable targetlesions that is not irradiated.

• D.At least one measurable lesion according to RECIST version 1.1

• E.Ability to understand and willingness to sign a written informed consent document.

• F.ECOG performance status 0-1

• G.Age of 20 years or above

• H.Adequate organ function as defined by the following criteria:

absolute neutrophil count (ANC) ≥ 1,500/mm3 hemoglobin level ≥ 9 g/dL platelet count ≥ 100,000/mm3 total bilirubin ≤ 2 ULN or ≤5 ULN if caused by biliary obstruction and achieving adequate drainage judged by investigator aspartate aminotransferase (AST) / alanine aminotransferase (ALT) ≤ 3 x ULN or ≤ 5.0×ULN in the presence of liver metastases creatinine clearance rate (CCr) ≥ 50 mL/min (24-hour urine collection or calculated by Cockroft-Gault formula; male: [(140 - age) × weight (kg)]/[72 × serum creatinine(mg/dL)];female=male x 0.85

-I.Patients with childbearing potential shall have effective contraception for both the patient and his or her partner during the study.

Exclusion Criteria:

• A. Other malignancy within the past 5 years except for adequately treated localizedcancer or carcinoma in situ;All patients with other malignancy within the past 5years should notify PI before registration.

• B.Active or uncontrolled infection;

• C.Significant medical conditions that is contraindicated to study medication orrender patient at high risk from treatment complications at physician discretion

• D.Pregnant women or nursing mothers, or positive pregnancy test for women ofchildbearing potential.

• E.History of active autoimmune disease within 3 years or use of steroid more thanprednisolone 10mg/day.