Clinical Trial of High-dose Vitamin C for Advanced Pancreatic Cancer

Pharmacological Ascorbate for the Control of Metastatic and Node-Positive Pancreatic Cancer (PACMAN): A Phase II Trial

This is a phase II study. It is designed to provide information about if high-dose ascorbate (vitamin C) increases survival for pancreatic cancer patients. The hypothesis is that vitamin C is well tolerated and increases cancer treatment effectiveness, lengthening survival time for patients with advanced pancreatic cancer.

Adenocarcinoma of the pancreas is the fourth leading cause of cancer death in the United States and is increasing in incidence; the prognosis remains dismal. We propose to investigate an entirely new approach, using pharmacological ascorbate, combined with Gemcitabine, to treat this cancer. Intravenous ascorbate (i.e., ascorbic acid, vitamin C), but not oral ascorbate, produces high plasma concentrations, which are in the range that can be cytotoxic to tumor cells. Though ascorbate has been utilized in cancer therapy, few studies have investigated intravenous deliver of ascorbate. Preliminary studies from our group have demonstrated that 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 H2O2 mediates the increased susceptibility of pancreatic cancer cells to ascorbate-induced metabolic oxidative stress. Gemcitabine is the standard chemotherapy drug used to treat pancreatic cancer.

Inclusion Criteria:

• Patients must have a cytological or histological diagnosis of adenocarcinoma arising in the pancreas. Diagnosis from metastatic sampling is acceptable.

• Disease must be measured radiologically.

• Failed initial therapy or ineligible for definitive curative therapy.

• If prior treatment included radiation therapy, recurrent disease must be outside of the targeted volume.

• Age ≥ 18 years

• ECOG performance status 0-2 (Karnofsky > 50%, see Appendix A).

• Patients must have normal organ and marrow function as defined below:

  • leukocytes ≥ 3,000/mm3
  • absolute neutrophil count ≥ 1,500/mm3
  • platelets ≥ 100,000/mm3
  • total bilirubin < 2x institutional upper limit of normal
  • AST(SGOT) < 3x institutional upper limit of normal OR < 5x institutional upper limit of normal for patients presenting with liver metastases
  • ALT (SGPT) < 3x institutional upper limit of normal OR < 5x institutional upper limit of normal for patients presenting with liver metastases
  • PT/INR within normal institutional limits, unless patient is on warfarin or other antithrombotic agents
  • creatinine < 1.5 X institutional upper limit of normal OR creatinine clearance ≥ 60 mL/min/1.73 m2 for patients with creatinine levels above institutional normal.
  • Not pregnant. Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
  • Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

• Prior chemotherapy to treat metastatic disease.
• Adjuvant therapy (including radiation therapy) within 4 calendar weeks.
• Unresolved toxicities from prior therapy for the malignancy.
• G6PD (glucose-6-phosphate dehydrogenase) deficiency.
• Second malignancy other than non-melanoma skin cancers within the past 5 years.
• Excess consumption of alcohol where an excess of alcohol is defined as more than four of any one of the following per day: 30 mL distilled spirits, 340 mL beer, or 120 mL wine.
• Uncontrolled intercurrent illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, psychiatric illness/social situations, or any other condition that would limit compliance with study requirements as determined by study team members.
• Pregnant or lactating women: The risks of chemotherapy to a fetus/infant are well documented.