No Standard therapy has been approved for third-line therapy of advanced pancreatic cancer. K001 is peptidoglycan prepared from the marine microorganism, with an anti-tumor activity. Previously, the phase I study of K001 has shown that K001 was safety and had some effectiveness for pancreatic patients. Now, we would like to lunch a randomized, blinded, parallel-controlled, multi-center phase II/III study to compare the best support care (BSC) plus K-001 versus BSC plus placebo for the third-line and later treatment of patients with advanced pancreatic cancer.

Inclusion Criteria:

1. Older than 18 years.
2. Metastatic or locally advanced pancreatic ductal adenocarcinoma which is confirmed by primary and/or metastatic pathology/cytology examination.
3. Had received at least 2 lines chemotherapy regimen, and the disease is progression or the toxicity could not be tolerated.
4. At least 28 days after the last chemotherapy.
5. Had a disease status that was measurable or evaluable as defined by Response Evaluation Criteria in Solid Tumors (RECIST, version1.1).
6. Had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0, 1, or 2.
7. Adequate hepatic, renal, and hematologic functions (neutrophils ≥1.5×10^9/L, platelets ≥ 80×10^9/L,hemoglobin ≥90g/L, total bilirubin within 2.0×the upper limit of normal(ULN), albumin≥30g/L, and ALT and AST≤3×the ULN (If liver metastases, serum transaminase≤5×the ULN), serum creatine ≤ 1.5 x ULN and creatinine clearance rate > 30ml/min (Cockcroft-Gault).
8. For women of child-bearing age, the pregnancy test results (serum or urine) within 14 days before enrolment must be negative. They will take appropriate methods for contraception during the study until the 60 days post the last administration of study drug. For men (previous surgical sterilization accepted), will take appropriate methods for contraception during the study until the 60 days post the last administration of study drug.
9. Signed and dated informed consent.Willingness and ability to comply with scheduled visits, treatment plans, laboratory tests, and other study procedure

Exclusion Criteria:

1. Patients is not confirmed by pathology/cytology examination as pancreatic ductal adenocarcinoma.

2. Target lesions were once treated locally and does not exhibit progression recently.

3. Patients with already diagnosed central nervous system metastasis. Patients with clinical symptoms of central nervous system metastasis should be examined by MRI.

4. Patients with Vater 's ampullary carcinoma or biliary adenocarcinoma.

5. Subject with partial or complete intestinal obstruction,or complete biliary obstruction who are unable to be relieved by active treatment

6. Subject has more than an average of intra-abdominal effusion, or the intra-abdominal effusion could not be control in 2 weeks.

7. Subject has a second malignancy other than curatively resected basal cell carcinoma of the skin, squamous cell carcinoma of the skin, in situ carcinoma of the cervix, or other cancers treated with curative intent and no known active disease within 5 years before planned start of study therapy.

8. Female subjects who are pregnant, planning a pregnancy or breast feeding during the study.

9. Subject has an active infection, or a hypertension could not be controlled by drugs, or angina diagnosed within 3 months, or unstable angina pectoris, or myocardial infarction diagnosed within 1 year, or with congestive heart failure (New York Heart Association [NYHA] Class II or III or IV), or with schizophrenia, or with the history of psychotropic substance abuse.

10. Subject has an active infection of hepatitis B (HBV), hepatitis C (HCV) or human immunodeficiency virus (HIV).

11. Subject has received any of the following treatment within the framework of a specific time frame prior to entry:

    1. received operation greater than grade II within 4 weeks;
    2. received extended range radiotherapy within 4 weeks, or locally radiotherapy within 2 weeks;
    3. participated in other therapeutic/interventional clinical trials within 4 weeks;
    4. received locally anti-tumor therapy within 4 weeks；

12. All toxic effects of any prior antitumor therapy resolved to Grade < 2 before the start of study therapy (with the exception of alopecia and pigmentation of skin).

13. Subject has known to be allergic or intolerant to K-001 and its excipients.

14. Other situations that the researchers considered inappropriate for inclusion in this study.

Double Blinded