A Study Comparing CO-1.01 With Gemcitabine as First Line Therapy in Patients With Metastatic Pancreatic Adenocarcinoma (LEAP)

Inclusion Criteria: * Metastatic pancreatic ductal adenocarcinoma (i.e., Stage 4). * Histological/cytological confirmation of metastatic tissue (not primary tumor) by a central pathology laboratory (H\&E stain) to ensure sufficient material is available for later hENT1 analysis. * Adjuvant chemotherapy/radiotherapy ≥ 6 months prior to randomization. * Palliative radiotherapy (if administered) ≥ 1 month prior to randomization. * CT scan ≤30 days prior to randomization * Performance Status (ECOG) 0 or 1. * Estimated life expectancy ≥ 12 weeks. * Age ≥ 18 years. * Adequate hematological and biological function. * Written consent on an Institutional Review Board/Institutional Ethics Committee-approved Informed Consent Form prior to any study-specific evaluation. Exclusion Criteria: * Prior palliative chemotherapy for pancreatic cancer. * Radical pancreatic resections (e.g., Whipple procedure) are not allowed \< 6 months prior to randomization. Exploratory laparotomy, palliative (e.g., bypass) surgery, or other procedures (e.g., stents) are not allowed \< 14 days prior to randomization. In both cases the patient must be sufficiently recovered and stable. * Symptomatic brain metastases. * Participation in other investigational drug clinical studies ≤ 30 days prior to randomization. * Concomitant treatment with prohibited medications. * History of allergy to gemcitabine or eggs. * Presence of any serious or unstable concomitant systemic disorder incompatible with the clinical study (e.g., substance abuse, uncontrolled intercurrent illness including active infection, arterial thrombosis, symptomatic pulmonary embolism). * Any disorder that would hamper protocol compliance. * Prior nonpancreatic malignancy treated with chemotherapy. Prior malignancies treated with surgery or radiotherapy alone must be in remission ≥ 3 years. The following prior malignancies are allowable irrespective of when they occurred: in situ carcinoma of the cervix, in situ ductal breast cancer, low-grade local bladder cancer, and nonmelanotic skin cancer. * Females who are pregnant or breastfeeding. * Refusal to use adequate contraception for fertile patients (females and males during the study and for 6 months after the last study treatment). Adequate forms of contraception are double-barrier methods (condoms or diaphragm with spermicidal jelly or foam); oral, depot, or injectable contraceptives; intrauterine devices; tubal ligation. * Any other reason the investigator considers the patient should not participate in the study.