Paclitaxel Protein Bound Plus Cisplatin Plus Gemcitabine and Paricalcitol for Pancreatic Adenocarcinoma (NABPLAGEMD)

Inclusion Criteria:

1. Age ≥18 years of age; male or female.
2. Histologically or cytologically confirmed metastatic pancreatic ductal adenocarcinoma.
3. Capable of providing informed consent and complying with trial procedures including obtaining paired biopsies during therapy
4. Karnofsky Performance Status (KPS) of ≥ 70%.
5. Life expectancy ≥ 12 weeks.
6. Measurable tumor lesions according to RECIST 1.1 criteria.
7. Women must agree not to become pregnant (e.g. post-menopausal for at least 1 year, surgically sterile, or practicing adequate birth control methods) for the duration of the study and until 90 days after last dose of study treatment. Women of child bearing potential must have a negative serum or urine pregnancy test at the Screening Visit and be non-lactating. Both male and female patients of reproductive potential must agree to use a reliable method of birth control during the study.

Exclusion Criteria:

1. Patients must have received no previous radiotherapy, surgery, chemotherapy or investigational therapy for the treatment of metastatic disease. Prior treatments in the adjuvant setting with gemcitabine and/or Fluorouracil (5-FU) or gemcitabine administered as a radiation sensitizer are allowed, provided at least 6 months have elapsed since completion of the last dose and no lingering toxicities are present.
2. Palliative surgery and/or radiation treatment less than 4 weeks prior to initiation of study treatment.
3. Exposure to any investigational agent within 4 weeks prior to initiation of study treatment.
4. Evidence of central nervous system (CNS) metastasis (negative imaging study, if clinically indicated, within 4 weeks of Screening Visit).
5. History of other malignancies (except cured basal or squamous cell carcinoma, superficial bladder cancer, prostate cancer in active surveillance, or carcinoma in situ of the cervix) unless documented free of cancer for ≥2 years.
6. Laboratory values: Screening serum creatinine \>1.5 mg/dL; total bilirubin \> (ULN); alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≥ 2.5x ULN or ≥ 5.0×ULN if liver metastases are present; absolute neutrophil count \<1,500/mm3, platelet concentration \<100,000/mm3, hematocrit level \<27% for females or \<30% for males, or coagulation tests (prothrombin time \[PT\], partial thromboplastin time \[PTT\], International Normalized Ratio \[INR\]) \>1.5×ULN unless on anticoagulation agents.
7. Current, serious, clinically significant cardiac arrhythmias as determined by the investigator.
8. History of HIV infection.
9. Active, clinically significant serious infection requiring treatment with antibiotics, antivirals or anti-fungals.
10. Any condition that might interfere with the patient's participation in the study or in the evaluation of the study results.