Inclusion Criteria:

- Adult patients, >/= 18 years of age

- Histologically confirmed adenocarcinoma of the stomach or gastro-esophageal junction

- Metastatic disease involving at least 2 organs (at least liver or lung or both)

- HER2-positive primary or metastatic tumor

- Adequate renal function

- Eastern Cooperative Oncology Group (ECOG) performance status 2

Exclusion Criteria:

- Previous chemotherapy for locally advanced or metastatic disease

- Prior gastrectomy (partial or total) for the underlying malignant disease under
investigation

- Prior therapy with an anti-HER2 agent and/or platinum-based chemotherapeutic agent

- Lack of physical integrity of the upper gastrointestinal tract or malabsorption
syndrome

- Current gastrointestinal bleeding

- Other malignancy within the last 5 years, except for carcinoma in situ of the cervix
or squamous cell carcinoma of the skin

- History of clinically significant cardio-vascular disease or disorder

- Chronic high-dose corticosteroid therapy

- History or clinical evidence of brain metastases

- Pregnant women

- Active infection with HIV, hepatitis B, hepatitis C, or HIV-positive