The purpose of this study is to evaluate the efficacy of low-dose vitamin C on improving the quality of life for metastatic pancreatic cancer patients receiving gemcitabine and nab-paclitaxel chemotherapy.

Pancreatic cancer is a highly lethal malignancy with a 5-year survival less than 10%. Approximately 80% of patients with pancreatic cancer are diagnosed at an advanced stage. Chemotherapy is one of the major treatments for advanced pancreatic cancer. The Metastatic PAncreatic Cancer Trial (MPACT) has confirmed the efficacy of gemcitabine combined with nab-paclitaxel as the first-line treatment to metastatic pancreatic cancer. However, the side-effects related to gemcitabine combined with nab-paclitaxel including anemia, hand/foot numbness, fatigue, nausea, and malnutrition have impaired the tolerability of the regimen.

Vitamin C, also called ascorbate, is an essential nutrient for the human body. It modulates metabolism, immune reaction, collagen synthesis, and iron absorption. Some studies have shown that high-dose intravenous Vitamin C may be effective against various types of cancer. Meanwhile, medium or low dose of Vitamin C may enhance the tolerability of chemotherapy by increasing iron absorption, improving anemia, alleviating pain and hand/foot numbness, and thus improving quality of life for patients with pancreatic cancer.

The purpose of this study is to evaluate the efficacy of low-dose vitamin C on improving the quality of life for metastatic pancreatic cancer patients receiving gemcitabine and nab-paclitaxel chemotherapy. One hundred patients will be randomly assigned to the experimental group (gemcitabine combined with nab-paclitaxel, Vitamin C) or the control group (gemcitabine combined with nab-paclitaxel). Rate of anemia, rate of hand/foot numbness, severity of pain, quality of life, and overall survival are measured every four weeks.

Inclusion Criteria:

• Ability to understand and the willingness to sign a written informed consent document.
• Age ≥ 18 years and ≤ 80 years.
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
• Histologically or cytologically confirmed metastatic pancreas adenocarcinoma.
• Adequate organ performance based on laboratory blood tests.
• Presence of at least of one measurable lesion in agreement to Response Evaluation Criteria in Solid Tumours (RECIST) criteria.
• Hemoglobin (Hgb) ≥ 8 g/dL.
• The expected survival ≥ 3 months.
• Women of childbearing potential and men must agree to use adequate contraception prior to study entry and for the duration of study participation.

Exclusion Criteria:

• Patients who have received any form of anti-tumor therapy.
• The diagnosis was confirmed by pathology as non-adenocarcinoma of pancreas.
• Inflammation of the digestive tract, including pancreatitis, cholecystitis, cholangitis, etc.
• Pregnant or nursing women.
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency.
• Severe and uncontrollable accompanying diseases that may affect protocol compliance or interfere with the interpretation of results, including active opportunistic infections or advanced (severe) infections, and diabetes that cannot be controlled after adequate clinical anti-hyperglycemia treatment according to guidelines, uncontrollable hypertension, cardiovascular disease (Class III or IV heart failure as defined by the New York Heart Association classification, congestive heart failure (CHF), myocardial infarction in the past 6 months , unstable arrhythmia or unstable angina, cerebral infarction within 3 months, etc).
• Renal insufficiency or dialysis
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to gemcitabine, nab-paclitaxel, or other agents used in the study.
• Other serious accompanying illnesses, which, in the researcher's opinion, could seriously adversely affect the safety of the treatment.
• Patients who are unwilling or unable to comply with study procedures.