Gemcitabine, Nab-Paclitaxel, and Bosentan for the Treatment of Unresectable Pancreatic Cancer

Main Inclusion Criteria * Adult patients with unresectable pancreatic carcinoma * Patients must be a candidate to receive one of the following chemotherapy combinations as determined by the treating physician: Arm A2: gemcitabine plus nab-paclitaxel given every 2 weeks (arm A1 is closed per this amendment) Arm B: mFOLFIRINOX given every 2 weeks * Willingness to permit study team to obtain and use archival tissue, if already existing, or, be willing to undergo a fresh tumor biopsy if clinically possible (exceptions may be provided by study PI if medically unsafe to perform biopsy). * Weight ≥ 40 kg * ANC ≥ 1500/mm3; platelets ≥ 100,000/mm3 * AST, ALT ≤ 1.5 x ULN. Patients with liver metastases ≤ 3 x ULN * Total serum bilirubin ≤ 1.5 x ULN * Creatinine clearence ≥ 60 mL/min Main Exclusion Criteria * Current or planned use of Warfarin, Cyclosporine A, Rifampicin, Glyburide (other diabetic medications are allowed) * Current or planned use of agents contraindicated for use with strong CYP3A4 inducers * Strong inhibitors or inducers of CYP2C9 * Strong inhibitors or inducers of CYP3A * Agent or agents that moderately inhibit both CYP2C9 and CYP3A (via a single concomitant agent, or co-administration of concomitant agents) * No other prior malignancy is allowed except for the following: adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, adequately treated Stage I or II cancer from which the patient is currently in complete remission, or any oth…