Study of Gemcitabine, Abraxane® Plus Placebo Versus Gemcitabine, Abraxane® Plus 1 or 2 Truncated Courses of Demcizumab in Subjects With 1st-Line Metastatic Pancreatic Ductal Adenocarcinoma

Inclusion Criteria: 1. Subjects must have histologically confirmed metastatic pancreatic ductal adenocarcinoma.. Prior chemotherapy and/or radiotherapy either in the adjuvant or neoadjuvant setting or for metastatic disease is not allowed. 2. Availability of formalin-fixed paraffin-embedded (FFPE) tumor tissue (from either the primary tumor, locoregional disease or a metastatic site), either fresh core-needle-biopsied or archived (two FFPE cores preferred whenever possible). If fresh tissue is obtained, the core biopsy must be done at least 7 days prior to randomization. 3. Age ≥21 years 4. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 5. Measurable disease per RECIST v1.1 5. Adequate organ and marrow function 6. Signed Informed Consent Form 7. For women of childbearing potential, agreement to use two effective forms of contraception Exclusion Criteria: 1. Subjects with a neuroendocrine tumor of the pancreas, an acinar tumor of the pancreas or a pancreatic tumor with mixed histologies. 2. Subjects receiving heparin, warfarin, factor Xa inhibitors or other similar anticoagulants. Note: Subjects may be receiving low-dose aspirin and/or non-steroidal anti-inflammatory agents. 3. Subjects with brain metastases, leptomeningeal disease, uncontrolled seizure disorder, or active neurologic disease 4. Subjects with Grade \>2 peripheral neuropathy 5. Subjects with clinically significant ascites 6. Malignancies other than pancreatic cancer successfully treated within 3 years prior to randomization, except for adequately treated carcinoma in situ of the cervix, basal or squamous cell skin cancer, treated superficial bladder cancer, localized prostate cancer treated surgically with curative intent, ductal carcinoma in situ treated surgically with curative intent 7. Significant intercurrent illness that will limit the patient's ability to participate in the study or may result in their death over the next 18 months 8. History of a significant allergic reaction attributed to humanized or human monoclonal antibody therapy 9. Subjects with known clinically significant gastrointestinal disease including, but not limited to, inflammatory bowel disease 10. Pregnant women or nursing women 11. Subjects with known HIV infection 12. Known bleeding disorder or coagulopathy