• Written informed consent obtained from the patient prior to performing any protocol-related procedures, including screening evaluations.

• Willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up.

• Histologically or cytologically proven Pancreatic Ductal Adenocarcinoma (PDAC).

• Metastatic disease.

• Measurable or evaluable lesions according to RECIST v1.1 criteria.

• First-line therapy (previous neoadjuvant/adjuvant chemotherapy not allowed).

• Age ≥ 18 years (no upper limit, patients ≥ 75 years old must have a G8 score ≥ 14).

• 3\. Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0-1.

• Availability of tumor tissue sample from the primary pancreatic tumor or liver metastasis (chemo-naïve) before inclusion in step 1.

⁃ Adequate organ function, as defined by the following (blood test ≤ 7 days prior to inclusion):

∙ Serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) ≤ 3 x upper limit of normal (ULN) (≤ 5 ULN in case of liver metastases)

‣ Total serum bilirubin ≤ 1.5 ULN

‣ Serum albumin ≥ 28 g/L

‣ Hemoglobin ≥ 9.0 g/dl

‣ Absolute neutrophil count (ANC) ≥ 1,500/μL

‣ Platelets ≥ 100,000/μL

‣ Creatinine clearance ≥ 50 mL/min (MDRD).

⁃ No Dihydropyrimidine dehydrogenase (DPD) deficiency (normal uracil level).

⁃ Life expectancy ≥ 3 months.

⁃ a. Evidence of post-menopausal status b. (or) negative urinary or serum pregnancy test for female pre-menopausal patients.

⁃ Registration in a National Health Care System.