Study of IDO Inhibitor in Combination With Gemcitabine and Nab-Paclitaxel in Patients With Metastatic Pancreatic Cancer

This is a Phase I/II trial designed to evaluate the combination of the immunotherapeutic agent indoximod and the standard of care chemotherapy gemcitabine plus nab-paclitaxel in subjects with metastatic adenocarcinoma of the pancreas. The phase 1 portion is designed to identify the regimen-limiting toxicity (RLT) and recommended phase 2 dose (RP2D) for the combination. The phase 2 portion of the study will evaluate the potential efficacy of this combination. All subjects will receive the standard 28-day gemcitabine plus nab-paclitaxel regimen. Twice daily oral indoximod will be administered concurrently in continuous 28 day cycles. In the phase 1 portion, dose escalation of indoximod will begin at 600 mg twice a day and potentially escalate to 1200 mg twice a day. There will be no intra-subject dose escalation. Regimen-limiting toxicity will be considered as those toxicities related to indoximod that significantly limit the administration of the backbone chemotherapy gemcitabine plus nab-paclitaxel. The period for determination of dose-limiting toxicities will be the initial 28 days of treatment. The recommended phase 2 dose will include an assessment of toxicities that occur at later time points. Once a RP2D is determined, the phase 2 portion of the study will be initiated. In both phase 1 and phase 2, every 2 cycles subjects will have repeat imaging to assess response. Corollary biomarkers will be assessed at the same interval as will PET-CT after the 1st 8 week cycle. Up to 18 patients will be enrolled in the phase 1 portion of the study and 80 patients will be enrolled in the phase 2 portion.