Nab-paclitaxel Plus S-1(AS) Versus Nab-paclitaxel Plus Gemcitabine(AG) in Patients With Advanced Pancreatic Cancer

Inclusion Criteria:

1. Signed informed-consent form.
2. Age no less than 18 years.
3. Histologically confirmed locally advanced or metastatic pancreatic ductal adenocarcinoma, with RECIST measurable lesions.
4. Eastern Cooperative Oncology Group (ECOG) 0-1 with life expectation of no less than 12 weeks.
5. Patients must have received no previous chemotherapy or investigational therapy for the treatment of locally advanced or metastatic disease.
6. At least 4 weeks since completion of the last operation except for diagnostic biopsy.
7. At least 4 weeks since completion of radiotherapy to lesions.
8. Not suitable for local treatment.
9. Adequate liver/bone marrow function.
10. Human Chorionic Gonadotropin (HCG) test negative for female with contraception measure until 3 months after study end.
11. Compliant, and can be followed up regularly.

Exclusion Criteria:

1. Received chemotherapy or investigational therapy for the treatment of locally advanced or metastatic disease.
2. Pregnant or breast-feeding female, or not willing to take contraception measures during study.
3. Serious infection requiring antibiotics intervention during recruitment.
4. Allergic to study drug.
5. More than grade 1 neuropathy.
6. Uncontrolled brain metastasis or mental illness.
7. Congestive heart failure, uncontrolled cardiac arrhythmia, etc.
8. Other malignancy within 5 years.
9. Can't be followed up or obey protocol.
10. Ineligible by the discretion of the investigator.