A Study of Ramucirumab in Participants With Gastric or Gastroesophageal Junction Adenocarcinoma

The main purpose of this study is to evaluate the effectiveness of S-1 and oxaliplatin with or without ramucirumab as first line therapy in participants with metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma.


Eligibility Criteria:
Inclusion Criteria:

* Have a histopathologically or cytologically confirmed diagnosis of metastatic gastric or GEJ adenocarcinoma. Participants with esophageal cancer are not eligible.
* Have not received any prior first-line systemic therapy for gastric or GEJ adenocarcinoma (prior adjuvant or neoadjuvant therapy is permitted). Participants whose disease has progressed after \>24 weeks following the last dose of systemic treatment in the adjuvant/neoadjuvant setting are eligible.
* Have measurable or nonmeasurable but evaluable disease determined using guidelines in Response Evaluation Criteria in Solid Tumors, Version 1.1 (RECIST v.1.1).
* Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale at baseline.
* Have adequate organ function.
* Have an estimated life expectancy of ≥12 weeks in the judgment of the investigator.
* Eligible participants of reproductive potential (both sexes) must agree to use contraception (hormonal or barrier methods) during the study period and at least 6 months after the last dose of study treatment or longer if required per local regulations.
* Are willing to provide a blood sample for research purposes. Submission of a blood sample is mandatory for participation in this study unless restricted by local regulations or ethical review boards (ERBs); submission of a tumor tissue sample is optional.

Exclusion Criteria:

* Participants with human epidermal growth factor receptor 2 (HER2)-positive status as determined per local standards. Participants with a negative test or having an indeterminate result due to any reason are eligible, provided these participants are not eligible for treatment directed against tumors which overexpress HER2.
* Have radiation therapy within 14 days prior to randomization. Any lesion requiring palliative radiation or which has been previously irradiated cannot be considered for response assessment.
* Have documented brain metastases, leptomeningeal disease, or uncontrolled spinal cord compression.
* Have undergone major surgery within 28 days prior to randomization.
* Are currently enrolled in, or discontinued study drug within the last 28 days from, a clinical trial involving an investigational product or non-approved use of a drug or device (other than the study drug used in this study), or are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study. Participants participating in surveys or observational studies are eligible to participate in this study.
* Are pregnant or breast feeding. Females of childbearing potential must have a negative serum or urine pregnancy test within 7 days prior to first dose of study treatment.
* Have any prior malignancies.
* Have any condition (eg, psychological, geographical, or medical) that does not permit compliance with the study and follow-up procedures or suggest that the participant is, in the investigator's opinion, not an appropriate candidate for the study.