Conditions: Gastric Cancer
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 296
Healthy volunteers: no

Brief summary:
This randomized, open-label, multicenter, international Phase IIIb study will compare the efficacy and safety of two Herceptin dosing regimens in combination with cisplatin/capecitabine chemotherapy in participants with HER2-positive metastatic gastric or gastro-esophageal junction adenocarcinoma. Participants who have not received prior treatment for metastatic disease will be randomized to receive Herceptin intravenously as either an 8-milligram per kilogram (mg/kg) loading dose followed by 6 mg/kg every 3 weeks (q3w) as standard of care or an 8-mg/kg loading dose followed by 10 mg/kg q3w until disease progression. Capecitabine will be administered for 6 cycles at a dose of 800 milligrams per meter-squared (mg/m\^2) orally twice a day on Days 1 to 14 of each 3-week cycle, and cisplatin will be administered intravenously for 6 cycles at a dose of 80 mg/m\^2 on Day 1 of each 3-week cycle. Herceptin will be continued until disease progression occurs.

Detailed description:

Arms:
arm 1: Participants will receive Herceptin at a loading dose of 8 mg/kg on Day 1 of Cycle 1 followed by 6 mg/kg q3w as a standard of care from Day 1 of Cycle 2 until disease progression, occurrence of unacceptable toxicity, or withdrawal from the study for another reason (cycle length = 21 days). Participants will also receive cisplatin 80 mg/m\^2 intravenously q3w plus capecitabine 800 mg/m\^2 orally twice daily for 14 days q3w for up to 6 treatment cycles (Cycles 1 to 6). arm 2: Participants will receive Herceptin at a loading dose of 8 mg/kg on Day 1 of Cycle 1 followed by 10 mg/kg q3w from Day 1 of Cycle 2 until disease progression, occurrence of unacceptable toxicity, or withdrawal from the study for another reason (cycle length = 21 days). Participants will also receive cisplatin 80 mg/m\^2 intravenously q3w plus capecitabine 800 mg/m\^2 orally twice daily for 14 days q3w for up to 6 treatment cycles (Cycles 1 to 6).

Interventions: intervention 1: Capecitabine intervention 2: Cisplatin intervention 3: Herceptin
Intervention descriptions: intervention 1: Capecitabine will be administered at a dose of 800 mg/m\^2 orally twice daily for 14 days q3w for up to 6 cycles (Cycles 1 to 6). intervention 2: Cisplatin will be administered at a dose of 80 mg/m\^2 intravenously q3w on Day 1 of each 3-week cycle for up to 6 cycles (Cycles 1 to 6). intervention 3: Herceptin will be administered at a loading dose of 8 mg/kg on Day 1 of Cycle 1 followed by 6 or 10 mg/kg (depending upon treatment assignment) q3w from Day 1 of Cycle 2 until disease progression, occurrence of unacceptable toxicity, or withdrawal from the study for another reason.

Protocol document: