This single-arm, Phase II clinical trial is to evaluate the efficacy and safety of nab-paclitaxel plus S-1 in locally advanced pancreatic cancer who were borderline resectable or unresectable .

This single-arm, Phase II clinical trial is to evaluate the efficacy and safety of nab-paclitaxel plus S-1 in locally advanced pancreatic cancer who were borderline resectable or unresectable . Nab-paclitaxel was administered at 125mg/m2 intravenously on day 1 and 8, S-1 （80, 100, or 120 mg/d according to body-surface area on days 1 through 14 of a 21-day cycle for 4-6 cycles.

During the study, if the subject's weight change was ≤10% from baseline, the dose was calculated based on the measured value at baseline. If the change was >10%, the body surface area of the subject should be recalculated and the dose administered should be adjusted. .

Study treatment period Borderline resectable: According to the results of imaging examination, MDT discussed to determine the surgical resectability and timing of surgery. The chemotherapy time was 4-6 cycles.

Unresectable: Chemotherapy for up to 6 cycles. According to the results of imaging examination, MDT determined the resectability of the operation. It was decided by the investigator and the patient to continue chemotherapy (S-1 maintenance), surgery or radiotherapy.

Inclusion Criteria:

• patient compliance is good, the research process of this study can be understood, and written informed consent is signed;
• Age ≥ 18 years old, ≤ 75 years old;
• Histologically or cytologically confirmed pancreatic adenocarcinoma；
• no prior treatment;
• Based on imaging findings, MDT decided patients intoborderline resectable (group A) or unresectable (group B) (according to the resectability assessment criteria in the 2018 Pancreatic Cancer Comprehensive Care Guidelines);
• ECOG<2;
• Bone marrow function: hemoglobin (HGB) ≥ 90g / L; absolute neutrophil count (ANC) ≥ 1.5 × 109 / L; platelets (PLT) ≥ 100 × 109 / L;
• Liver function: ALT, AST ≤ 2.5 × upper limit of normal (ULN), if there is liver metastasis, ALT, AST ≤ 5 × ULN; serum total bilirubin < 1.5 × ULN;
• Renal function: serum creatinine is within normal range;
• Patients without biliary obstruction, patients requiring biliary stent implantation must be completed at least 7 days prior to enrollment;
• Non-pregnant and lactating women, women of reproductive age/male should take effective contraceptive measures during the study period and within 6 months after the end of the study treatment;
• No contraindication to the use of S-1and albumin-bound paclitaxel.

Exclusion Criteria:

• Patients who have had other malignant tumors within 5 years (except for cured cervical cancer in situ or non-melanoma skin cancer);
• Interstitial pneumonia or pulmonary fibrosis;
• Severe pleural effusion or ascites;
• Watery diarrhea;
• There are serious concomitant diseases: such as HIV-positive,chronic HBV/HCV in active period, people who have diabetes and poorly controlled by hypoglycemic drugs, clinically severe (ie, active) heart disease, uncontrolled epilepsy, central nervous system disease or mental disorder;
• Current or previous patients with grade II peripheral neuropathy;
• Abnormal digestive tract or metabolic function, which may affect the s-1 absorber;
• Participated in other clinical researchers within 4 weeks prior to enrollment;
• Patients who have undergone organ transplantation;
• Patients considered by the investigator to be unfit for this trial.