PRIMUS 001: A Study Looking at Two Different Chemotherapy Regimens in Patients With Metastatic Pancreatic Cancer

Inclusion Criteria: 1. Patient has been enrolled in the Precision-Panc Master Protocol 2. Patient has provided signed information consent for the PRIMUS 001 study 3. Age ≥ 16 years 4. Histologically-confirmed pancreatic ductal adenocarcinoma and its varients 5. Measurable metastatic disease according to RECIST V1.1 6. Eastern Cooperative Oncology Group (ECOG) 0-1 with life expectation of no less than 12 weeks 7. Patients must have received no previous chemotherapy or investigational therapy for the treatment of metastatic disease. Prior treatment with a fluoropyrimidine and/or gemcitabine administered in the adjuvant setting is allowed, provided at least 6 months have elapsed since completion of the last dose and no ongoing toxicities are present 8. Adequate liver/bone marrow function as defined by: 1. Neutrophils (ANC) ≥ 1.5 x 109/l 2. Platelets ≥ 100 x 109/l 3. Haemoglobin ≥ 9.0 g/dL 4. White Blood Cells (WBC) ≥ 3 x 109/l 5. Total bilirubin ≤ 1.5 x institutional ULN unless bilirubin rise is due to Gilbert's syndrome 6. Aspartate transaminase (AST) and alanine aminotransferase (ALT) ≤ 2.5 x ULN ( \<5 ULN in the presence of liver metastases) 7. Estimated creatinine clearance ≥ 60 mL/min (as calculated by Cockcroft and Gault or Wright formula or measured by EDTA clearance) 9. Negative serum or urine Human Chorionic Gonadotropin (HCG) test for females with child bearing potential. Postmenopausal women must have been amenorrhoeic for at least 12 months to be considered of non-childbearing potential 10. Woman of child bearing potential, and men with female partners of child bearing potential, must agree to use adequate contraceptive measures (see s section 8.1.8.1) for the duration of the study and for up to 6 months after the completion of study treatment. 11. Compliant, and can be followed up regularly The following additional inclusion criteria is ONLY required if recommended by the independent Data Monitoring Committee after interim review of study data (sites will have been informed by the Cancer Research UK (CRUK) Clinical Trials Unit (CTU) if this is the case) 12. Patient must be biomarker positive as fed back after central Precision-Panc diagnostic testing Exclusion Criteria: 1. Prior treatment with nab-paclitaxel or oxaliplatin 2. Prior chemotherapy for metastatic pancreatic cancer 3. Known hypersensitivity for any component of any study drug 4. Active infection including Herpes Zoster and chickenpox 5. Current neuropathy ≥ grade 2 6. Uncontrolled brain metastasis 7. Uncontrolled congestive heart failure (CHF), or history of myocardial ischemia (MI), unstable angina, stroke, or transient ischemia within previous 6 months 8. Uncontrolled serious contraindicated medical condition or illness 9. Known or suspected dihydropyrimidine dehydrogenase (DPD) deficiency 10. Pregnant or breastfeeding 11. History of physical or psychiatric disorder that would prevent informed consent and compliance with protocol 12. Administration of any investigational drug within 28 days or 5 half-lives, whichever is longer, of receiving the first dose of trial treatment 13. Any systemic anti-cancer therapy or major surgery within 28 days of randomisation 14. Any minor surgery or radiotherapy within 7 days of randomisation 15. Any psychological, familial, sociological or geographical consideration potentially hampering compliance with the trial protocol and follow up schedule 16. Any patients receiving treatment with brivudin, sorivudin and analogues 17. History of another malignancy in the last 5 years (other than treated squamous/basal cell skin cancer, treated early-stage cervical cancer or treated/biochemically-stable organ-confined prostate cancer) 18. Any patient with severe diarrhoea (defined as ≥grade 3 diarrhoea despite maximum supportive measures and exclusion of underlying infection)