Safety & Efficacy Study of Gemcitabine...With High Dose IV Vit. C (HDIVC)

* The combination of gemcitabine and HDIVC is safe and may favorably change the clinical course for an individual patient.
* The combination of gemcitabine and HDIVC is synergistic in anti-tumor effect as seen in preclinical models, where HDIVC creates a pro-oxidative effect that adds to the anti-tumor effect of gemcitabine.
* The combination of gemcitabine and HDIVC may improve Progression Free Survival (PFS).
* The dosage schema of 1.2 g /kg bolus infusion followed by lower dose of 0.3 g / kg infusion may create sustained elevation in Vitamin C plasma levels for increased cytotoxic effect.
* The addition of HDIVC \& oral supplementation of Vitamin C to standard treatment with gemcitabine may improve quality of life for patients with comparison to prior to treatment start of this protocol.
* CA 19-9 and inflammatory markers may show trends for patients in this trial.


Eligibility Criteria:
Inclusion Criteria:

* Patient ≥ 18 years of age
* Biopsy proven adenocarcinoma of the pancreas
* Evidence of metastatic disease
* Received at least 1 prior chemotherapy treatment regimen with disease progression
* May have had any prior chemotherapy regimen including any gemcitabine based regimen or FOLFIRINOX
* May have participated in a prior study protocol
* May have had prior treatment with HDIVC
* Anticipated survival of at least 3 months
* Eastern Cooperative Oncology Group (ECOG) performance status = 0,1, or 2
* The patient must have screening laboratory: ANC ≥ 1,500/mm3, Hemoglobin \> 8g/dL, Platelets ≥ 100,000/mm3, Total Bilirubin \< 1.5mg/dL, Creatinine ≤ 1.5mg/dL, Transaminases \< 2.5 x upper limit of normal, Urine Uric Acid \< 1.000 mg/d, Urine pH \< 6, Urine microscopic negative for oxalates (if positive, reflex urinary oxalates \< 60mg/d), PT INR ≤ 1.5, unless patient is on full dose warfarin
* Glucose-6-phosphate dehydrogenase deficiency (G6PD) normal status via blood test The fluorescent spot test is the simplest, most reliable, and most sensitive of the G6PD screening tests
* Willingness to undergo central line placement and able to manage care of the entry site safely
* Willingness to adhere to supplemental oral dose regimen of ascorbic acid 500mg taken twice daily
* All other nutritional supplements would be discontinued for the duration of the trial except for pancreatic enzymes and probiotics
* Patients must be able to take food orally or have a peg tube for feeding
* Able to give consent for protocol participation

Exclusion Criteria:

* Glucose-6-phosphate dehydrogenase deficiency (G6PD)
* Renal insufficiency : serum creatinine of \> 1.5 mg /dl or evidence of oxalosis by urinalysis prior to enrollment and prior to each HDIVC infusion
* Documentation or report of history of kidney stones or urinary oxalosis.
* Co-morbid condition that would affect survival: congestive heart failure, unstable angina, myocardial infarction within 6 weeks of study, uncontrolled blood sugars of \> 300 mg / dl, patients with known chronic active hepatitis or cirrhosis
* Currently active second malignancy
* Chronic hemodialysis
* Iron overload/ Hemochromatosis: Ferritin \> 500 ng / ml
* Wilson's disease
* Pregnant or lactating female (pre- menopausal females will undergo pregnancy test prior to administration of protocol drugs throughout treatment cycles during this study)
* Aspirin use exceeding 81 mg per day
* Acetaminophen use exceeding 2 g per day
* Known brain metastasis
* Active tobacco smokers
* Treatment with the combination of HDIVC and gemcitabine previously