Paricalcitol and Hydroxychloroquine in Combination With Gemcitabine and Nab-Paclitaxel for Advanced Pancreatic Cancer

PRIMARY OBJECTIVE: I. To evaluate the anti-tumor activity of the combination of paricalcitol plus hydroxychloroquine (PH) when added to gemcitabine and nab-paclitaxel treatment by assessing the overall response rate (ORR) by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. SECONDARY OBJECTIVES: I. To evaluate the safety and tolerability of the combination of paricalcitol plus hydroxychloroquine (PH) when added to gemcitabine and nab-paclitaxel treatment in patients with advanced pancreatic cancer. II. To evaluate the anti-tumor activity of the combination of paricalcitol plus hydroxychloroquine (PH) when added to gemcitabine and nab-paclitaxel treatment by assessing progression-free survival (PFS) and overall survival (OS). TERTIARY/EXPLORATORY OBJECTIVES: I. Evaluate the effects of PH on cancer-associated fibroblasts (CAF) and immune cells using mass cytometry (CyTOF) to characterize the presence and distribution of these cells. II. Multiplex immunohistochemistry (IHC) to evaluate these pathways including TGF-beta1, TGF-beta1 RII, SMAD4, LC3 in addition to markers of fibrosis (collagen) and tumor (cytokeratin). OUTLINE: Beginning day -14, patients receive paricalcitol intravenously (IV) three times weekly and hydroxychloroquine orally (PO) twice daily (BID). Patients also receive gemcitabine IV over 30 minutes and nab-paclitaxel IV over 30 minutes on days 1, 8, 15. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 28 days and every 12 weeks thereafter.