A Phase 2 Trial of High-dose Ascorbate for Pancreatic Cancer (PACMAN 2.1)

One of the standard treatments for metastatic pancreatic adenocarcinoma is nab-paclitaxel with gemcitabine. This standard therapy administers chemotherapy once per week for three weeks; patients then get a 'rest week' to complete the cycle (1 cycle = 4 weeks). This study adds 75 grams of ascorbate (vitamin C, sometimes called pharamcological ascorbate because the dose is so high) to standard therapy. The ascorbate is administered intravenously - through a vein in the arm. Participants in the control group will: * receive gemcitabine and nab-paclitaxel chemotherapy, which is standard for their cancer. * undergo imaging which is standard for their cancer and therapy. This can include CT scans, PET scans, and X-rays Participants in the intervention group will: * receive 75 grams of ascorbate 3 times per calendar week for each week of the chemotherapy cycle. * undergo imaging which is standard for their cancer and therapy. This can include CT scans, PET scans, and X-rays * provide blood samples to determine the biological effects, if any, the ascorbate has on the body during therapy. This active therapy portion lasts until the disease progresses and a new treatment needs to be adopted - this can be months to years. If disease progresses, participants go back to standard follow-up for their caner and the new/additional therapy their doctors prescribe. However, it is very important we remain in contact with participants; they will have life-long follow-up for this study.