Inclusion Criteria:

          -  A female subject is eligible to participate if she is not pregnant or lactating and at
             least 1 of the following conditions applies:

               -  Not a woman of childbearing potential (WOCBP) OR

               -  WOCBP who agrees to follow the contraceptive guidance throughout the treatment
                  period and for at least 6 months after the final study drug administration.

          -  Female subject must agree not to breastfeed starting at screening and throughout the
             study period, and for 6 months after the final study drug administration.

          -  Female subject must not donate ova starting at screening and throughout the study
             period, and for 6 months after the final study drug administration.

          -  A male subject with female partner(s) of child-bearing potential must agree to use
             contraception during the treatment period and for at least 6 months after the final
             study drug administration.

          -  A male subject must not donate sperm during the treatment period and for at least 6
             months after the final study drug administration.

          -  Male subject with a pregnant or breastfeeding partner(s) must agree to remain
             abstinent or use a condom for the duration of the pregnancy or time partner is
             breastfeeding throughout the study period and for 6 months after the final study drug
             administration.

          -  Subject agrees not to participate in other interventional studies while receiving
             study drug in present study.

          -  Subject has histologically or cytologically confirmed adenocarcinoma of pancreas.

          -  Subjects must have metastatic pancreatic adenocarcinoma that has not been previously
             treated with chemotherapy.

               -  Prior treatment with fluorouracil (5-FU) or GEM administered as a radiation
                  sensitizer during and up to 4 weeks after radiation therapy is allowed

               -  If a subject received therapy in the adjuvant setting, tumor recurrence or
                  disease progression must have occurred at least 6 months after completing the
                  last dose of adjuvant therapy.

          -  Subject has a measurable lesion(s) on at least 1 metastatic site based on RECIST 1.1
             within 28 days prior to randomization. For subjects with only 1 measurable lesion and
             prior radiotherapy, the lesion must be outside the field of prior radiotherapy or must
             have documented progression following radiation therapy.

          -  Subject's tumor sample has CLDN18.2 expression in ≥ 75% of tumor cells demonstrating
             moderate to strong membranous staining as determined by central immunohistochemistry
             (IHC) testing

          -  Subject has Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

          -  Subject has predicted life expectancy ≥ 12 weeks.

          -  Subject must meet all of the following criteria based on the laboratory tests that
             will be collected within 14 days prior to randomization. In case of multiple
             laboratory data within this period, the most recent data should be used.

               -  Hemoglobin ≥ 9 g/dl (no transfusion within 14 days of start of study treatment)

               -  Absolute neutrophil count ≥ 1.5 x 10^9/L

               -  Platelets ≥ 100 x 10^9/L

               -  Albumin ≥ 2.5 g/dL

               -  Total bilirubin ≤ 1.5 x upper limit of normal (ULN)

               -  Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 x ULN
                  without liver metastases (≤ 5 x ULN if liver metastases are present)

               -  Estimated creatinine clearance ≥ 30 mL/min

               -  Prothrombin time/international normalized ratio (INR) and partial thromboplastin
                  time ≤ 1.5 x ULN (except for subjects receiving anticoagulation therapy)

        Exclusion Criteria:

          -  Subject has received other investigational treatment within 28 days prior to
             randomization.

          -  Subject has received radiotherapy for metastatic pancreatic adenocarcinoma ≤ 14 days
             prior to randomization and has not recovered from any related toxicity.

          -  Subject has received systemic immunosuppressive therapy, including systemic
             corticosteroids within 14 days prior to randomization. Subject using a physiologic
             replacement dose of hydrocortisone or its equivalent (defined as up to 30 mg per day
             of hydrocortisone or up to 10 mg per day of prednisone), receiving a single dose of
             systemic corticosteroids or receiving systemic corticosteroids as premedication for
             radiologic imaging contrast use are allowed.

          -  Subject has prior severe allergic reaction or intolerance to known ingredients of
             zolbetuximab or other monoclonal antibody, including humanized or chimeric antibodies.

          -  Subject has known immediate or delayed hypersensitivity, intolerance or
             contraindication to any component of study treatment.

          -  Subject has a known history of a positive test for human immunodeficiency virus
             infection or known active hepatitis B (positive HBs antigen [Ag]) or hepatitis C
             infection. NOTE: Screening for these infections should be conducted per local
             requirements.

               1. For subjects who are negative for HBs Ag, but hepatitis B core antibody positive,
                  a hepatitis B virus DNA test will be performed and if positive, the subject will
                  be excluded.

               2. Subjects with positive hepatitis C serology but negative hepatitis C virus RNA
                  test results are eligible.

               3. Subjects treated for hepatitis C with undetectable viral load results are
                  eligible.

          -  Subject has a history of interstitial pneumonia or pulmonary fibrosis.

          -  Subject has pleural effusion or ascites ≥ Grade 3.

          -  Subject has an active autoimmune disease that has required systemic treatment in the
             past 3 months prior to randomization.

          -  Subject has active infection requiring systemic therapy that has not completely
             resolved per investigator judgment within 7 days prior to randomization.

          -  Subject has significant cardiovascular disease, including:

               -  Congestive heart failure (defined as New York Heart Association Class III or IV),
                  myocardial infarction, unstable angina, coronary angioplasty, coronary stenting,
                  coronary artery bypass graft, cerebrovascular accident or hypertensive crisis
                  within 6 months prior to randomization;

               -  History of clinically significant ventricular arrhythmias (i.e., sustained
                  ventricular tachycardia, ventricular fibrillation or Torsades de Pointes);

               -  QTc interval > 450 msec for male subjects; QTc interval > 470 msec for female
                  subjects;

               -  Cardiac arrhythmias requiring anti-arrhythmic medications (Subjects with rate
                  controlled atrial fibrillation for > 1 month prior to randomization.)

          -  Subject has a history of central nervous system metastases and/or carcinomatous
             meningitis from pancreatic adenocarcinoma.

          -  Subject has known peripheral sensory neuropathy ≥ Grade 2 unless the absence of deep
             tendon reflexes is the sole neurological abnormality.

          -  Subject has had a major surgical procedure ≤ 28 days prior to randomization.

          -  Subject without complete recovery from a major surgical procedure ≤ 14 days prior to
             randomization.

          -  Psychiatric illness or social situations that would preclude study compliance.

          -  Subject has another malignancy for which treatment is required.

          -  Subject has any concurrent disease, infection or co-morbid condition that interferes
             with the ability of the subject to participate in the study, which places the subject
             at undue risk or complicates the interpretation of data.