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

PRIMARY OBJECTIVE: I. To assess the safety, toxicity and feasibility of administering bosentan with nab-paclitaxel and gemcitabine. SECONDARY OBJECTIVES: I. To assess the response rate associated with this combination therapy in first line pancreatic cancer patients. II. To assess the progression-free survival and overall survival of all patients who start protocol therapy, and describe the outcomes based on measures of compliance during the lead-in week, and compliance with supplement during chemotherapy. EXPLORATORY OBJECTIVES: I. To determine the impact of bosentan on the mass transport in the tumor (surrogate of alterations in tumor stroma and blood flow). (Pharmacodynamic Investigations) II. To describe the pharmacokinetic profile of nab-paclitaxel and bosentan and compare to historic single-agent profile. (Pharmacokinetic Investigations) III. To explore the association between hepatotoxicity to study agents and organic anion-transporting polypeptide (OATP) polymorphisms. (Pharmacogenomic Investigations) IV. To explore biomarkers on pre-treatment biopsy samples and peripheral blood samples for correlations of predictive of response. V. To describe quality of life utilizing the Functional Assessment of Cancer Therapy: General (FACT-G) questionnaire. OUTLINE: Patients receive bosentan orally (PO) twice daily (BID) on days -7 to 21 or 8-21 of cycle 1 and days 1-21 of subsequent cycles. Patients also receive nab-paclitaxel intravenously (IV) over 30 minutes and gemcitabine IV over 30 minutes on days 1, 8, and 15. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days. Patients who complete study treatment without disease progression are followed up every 2 months until disease progression and then biannually thereafter. Patients who complete study treatment with disease progression are followed up biannually.