a study of pertuzumab in combination with trastuzumab and chemotherapy in participants with human epidermal growth factor receptor 2 (her2)-positive metastatic gastroesophageal junction or gastric cancer

Conditions: Gastric Cancer

Summary: this double-blind, placebo-controlled, randomized, multicenter, international, parallel arm study will evaluate the efficacy and safety of pertuzumab in combination with trastuzumab, fluoropyrimidine and cisplatin as first-line treatment in participants with her2-positive metastatic gastroesophageal junction (gej) or gastric cancer (gc). participants will be randomized to receive pertuzumab 840 milligrams (mg) or placebo intravenously every 3 weeks (q3w) in combination with trastuzumab (initial dose of 8 milligrams per kilogram \[mg/kg\] intravenously \[iv\] followed by 6 mg/kg iv q3w) and cisplatin and fluoropyrimidine (capecitabine or 5-fluorouracil) for the first 6 treatment cycles. participants will continue to receive pertuzumab or placebo and trastuzumab until disease progression occurrence of unacceptable toxicity or withdrawal from the study for another reason.


Eligibility criteria:
inclusion criteria: * histologically confirmed metastatic adenocarcinoma of the stomach or gej * measurable or evaluable non-measurable disease as assessed by the investigator according to recist v1.1 criteria * eastern cooperative oncology group (ecog) performance status 0 or 1 * life expectancy greater than equal to (\>/=) 3 months exclusion criteria: * previous cytotoxic chemotherapy for advanced (metastatic) disease * evidence of disease progression documented within 6 months after completion of prior neoadjuvant or adjuvant cytotoxic chemotherapy, or both, or radiotherapy for gej adenocarcinoma * previous treatment with any her2-directed therapy, at any time, for any duration * previous exposure to any investigational treatment within 30 days before the first dose of study treatment * radiotherapy within 30 days before the first dose of study treatment (within 2 weeks if given as palliation to bone metastases, if recovered from all toxicities) * history or evidence of brain metastases * clinically significant active gastrointestinal (gi) bleeding (grade \>/=2 according to national cancer institute \[nic\]-common terminology criteria for adverse events version 4.0 \[ctcaev.4.0\]) * residual toxicity resulting from previous therapy (for example, hematologic, cardiovascular, or neurologic toxicity that is grade \>/=2). alopecia is permitted * other malignancy (in addition to gastric cancer \[gc\]) within 5 years before enrollment, except for carcinoma in situ of the cervix or squamous or basal cell carcinoma of the skin that has been previously treated with curative intent * inadequate hematologic, renal or liver function * pregnant or lactating women * history of congestive heart failure of any new york heart association (nyha) criteria * angina pectoris requiring treatment * myocardial infarction within the past 6 months before the first dose of study drug * clinically significant valvular heart disease or uncontrollable high-risk cardiac arrhythmia * history or evidence of poorly controlled hypertension * baseline left ventricular ejection fraction (lvef) value less than (\<) 55 percent (%) * any significant uncontrolled intercurrent systemic illness * positive for hepatitis b, hepatitis c or human immunodeficiency virus (hiv) infection