Exclusion criteria
Torsades de Pointes)QTc interval, malignancy, ≤28, autoimmune disease, coronary stenting, allergic reaction, toxicity, ventricular arrhythmias, cancer, infections, gastric outlet syndrome, persistent/recurrent vomiting, infection, adenocarcinoma, long QT syndromeCardiac arrhythmias, peripheral sensory neuropathy grade, psychiatric illness, human immunodeficiency virus (HIV) infection, coronary angioplasty
DIHYDROPYRIMIDINE DEHYDROGENASE DEFICIENCY, CARCINOMATOUS MENINGITIS, CARDIOVASCULAR DISEASE, UNSTABLE ANGINA, HEART, AUTOIMMUNE DISEASE, ALLERGIC REACTION, GASTRIC BLEEDING, VENTRICULAR ARRHYTHMIA, CANCER, INFECTIONS, HEPATITIS C INFECTION, HEPATITIS B, GASTRIC ULCERS, INFECTION, HEPATITIS C, ADENOCARCINOMA, METASTASES, CONGESTIVE HEART FAILURE, HYPERTENSIVE CRISIS, FIBRILLATION, VIRUS, MYOCARDIAL INFARCTION, DISEASE, CEREBROVASCULAR ACCIDENT, DELAYED HYPERSENSITIVITY, CONTROLLED ATRIAL FIBRILLATION
Prohibited treatment or therapies:Patient has received prior systemic chemotherapy for locally advanced unresectable or mG/GEJ adenocarcinoma. However, patient may have received either neoadjuvant or adjuvant chemotherapy, immunotherapy or other systemic anti-cancer therapies as long as it was completed at least 6 months before randomization.Patient has received radiotherapy for locally advanced unresectable or mG/GEJ adenocarcinoma ≤14 days before randomization and has not recovered from any related toxicity.Patient has received treatment with herbal medications or other treatments that have known anti-tumor activity within 28 days before randomization.Patient has received systemic immunosuppressive therapy, including systemic corticosteroids, within 14 days before randomization. Patient 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 is eligible.Patient has received other investigational agents or devices within 28 days before randomization.Medical history or concurrent disease:Patient has prior severe allergic reaction or intolerance to known ingredients of zolbetuximab or other monoclonal antibodies, including humanized or chimeric antibodies.Patient has known immediate or delayed hypersensitivity, intolerance or contraindication to any component of study treatment.Patient has prior severe allergic reaction or intolerance to any component of CAPOX.Patient has known dihydropyrimidine dehydrogenase deficiency. (Note that screening for dihydropyrimidine dehydrogenase deficiency should be conducted per local requirements.)Patient has a complete gastric outlet syndrome or a partial gastric outlet syndrome with persistent/recurrent vomiting.Per investigator judgment, patient has significant gastric bleeding and/or untreated gastric ulcers that exclude the patient from participation.Patient has a known history of a positive test for human immunodeficiency virus (HIV) infection or known active hepatitis B (HB; positive HB surface antigen (HBs Ag)) or hepatitis C infection. (Note: Screening for these infections should be conducted per local requirements.)For patients who are negative for HBs Ag but HB core antibody (HBc Ab) positive, an HB DNA test will be performed, and, if positive, the patient will be excluded.Patients with positive hepatitis C virus (HCV) serology but negative HCV RNA test are eligible.Patients treated for HCV with undetectable viral load results are eligible.Patient has an active autoimmune disease that has required systemic treatment within the past 3 months before randomization.Patient has an active infection requiring systemic therapy that has not completely resolved within 7 days before randomization.Patient has significant cardiovascular disease, including any of the following.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 before randomizationHistory of clinically significant ventricular arrhythmias (that is, sustained ventricular tachycardia, ventricular fibrillation or Torsades de Pointes)QTc interval >450 ms for male patients; QTc interval >470 ms for female patientsHistory or family history of congenital long QT syndromeCardiac arrhythmias requiring anti-arrhythmic medications (patients with rate controlled atrial fibrillation for >1 month before randomization are eligible)Patient has history of central nervous system (CNS) metastases and/or carcinomatous meningitis from G/GEJ cancer.Patient has known peripheral sensory neuropathy grade >1 unless the absence of deep tendon reflexes is the sole neurological abnormality.Patient has had a major surgical procedure ≤28 days before randomization.Patient without complete recovery from a major surgical procedure ≤14 days before randomization.Patient has psychiatric illness or social situations that would preclude study compliance, per investigator judgment.Patient has another malignancy for which treatment is required, per investigator judgment.Patient has any concurrent disease, infection or comorbid condition that interferes with the ability of the patient to participate in the study, which places the patient at undue risk or complicates the interpretation of data, in the opinion of the investigator.