A phase II trial of pharmacological ascorbate, gemcitabine, and nabpaclitaxel for metastatic pancreatic cancer.

Abstract

TPS791 Background: FOLFIRINOX or gemcitabine/nab-paclitaxel are both frontline chemotherapy options for patients with metastatic pancreas cancer. For most who cannot tolerate the triplet, the latter doublet is the preferred option. Through previous work by our group, pharmacologic ascorbate is known to synergize with gemcitabine; preliminary in vitro data from our group suggests a similar synergistic response with paclitaxel. Though ascorbate has been utilized in cancer therapy, few robust trials have investigated intravenous delivery of ascorbate to deliver plasma concentrations that are cytotoxic to tumor cells. Our prior studies have demonstrated ascorbate induces oxidative stress and cytotoxicity in pancreatic cancer cells; this cytotoxicity appears to be greater in tumor vs. normal cells. We hypothesize that production of hydrogen peroxide mediates the increased susceptibility of pancreatic cancer cells to ascorbate-induced metabolic oxidative stress, resulting in improved treatment outcomes, which has led to the development of the clinical trial (NCT02905578). Methods: All participants receive gemcitabine (1000 mg/m2 weekly) and nab-paclitaxel (125 mg/m2) on cycle days 1, 8, and 15 of a 28-day cycle. Participants are randomized to ± pharmacologic ascorbate (75-gram infusion 3x weekly) in addition to chemotherapy. Study therapy continues until tumor progression. The primary objective is to determine overall survival in patients when treated with combination gemcitabine, nab-Paclitaxel and high-dose ascorbic acid compared to gemcitabine and nab-paclitaxel in patients with non-resectable pancreatic cancer. Secondary objectives include determining objective response rate as well as progression free survival using RECIST 1.1 criteria employing a blinded reviewer for RECIST measurements. The study opened to accrual in 2018 with a goal of enrolling 65 participants. Oversight.Study is conducted under IND 105715 (J. Cullen, sponsor). The University of Iowa Biomedical IRB (IRB-01) serves as the IRB of record. Clinical trial information: NCT02905578.