Conditions: Metastatic Diffuse Gastric Cancer Including Carcinoma of the Gastro-esophageal Junction
Keywords: Gastric Cancer , S-1, Phase 3
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 361
Healthy volunteers: no

Brief summary:
The purpose of this study is to evaluate the safety and efficacy of S-1 and Cisplatin compared to 5-FU and Cisplatin in treatment of patients with metastatic diffuse gastric and gastro-esophageal junction cancer previously untreated with chemotherapy.

Detailed description:
This is an open-label, international, Phase 3 study evaluating the efficacy and safety of the S-1/cisplatin regimen versus the 5-FU/cisplatin regimen in chemotherapy-naïve patients with metastatic diffuse gastric carcinoma including carcinoma of the gastro-esophageal junction. Patients will be randomly assigned to S-1/cisplatin (experimental regimen, Arm A) or 5-FU/cisplatin (control regimen, Arm B).

Arms:
arm 1: Participants received S-1 25 milligrams per meter square (mg/m\^2) orally twice daily (BID) every 12 hours from Day 1 through Day 21, 1 hour before or after meal with a glass of water; followed by a 7-day rest period from Day 22 to Day 28 in a 28-day cycle. Participants received a single dose of cisplatin 75 mg/m\^2 as a 1- to 3-hour intravenous (IV) infusion on Day 1 following the morning dose of S-1 for a maximum of 8 cycles (each cycle of 28 days). Participants received study medication until progression of disease (PD), adverse event (AE), withdrawal of consent, or other reason for discontinuation, whichever happened earlier. arm 2: Participants received 5-Fluorouracil (5-FU) 800 mg/m\^2 per 24 hours as continuous IV infusion over 120 hours from Day 1 through Day 5 followed by a 16-day rest period on Days 6 through 21 in a 21-day cycle. Participants received a single dose of cisplatin 80 mg/m\^2 as a 1- to 3-hour IV infusion on Day 1 prior to the start of the 5-FU infusion on Day 1 for a maximum of 8 cycles (each cycle of 21 days). Participants received study medication until PD, AE, withdrawal of consent, or other reason for discontinuation, whichever happened earlier.

Interventions: intervention 1: S-1 (Tegafur+Gimeracil+Oteracil) /cisplatin (investigational arm) intervention 2: Fluorouracil/cisplatin (control arm)
Intervention descriptions: intervention 1: 25 mg/m² body surface area (BSA) orally 2 times daily from Days 1 through 21 followed by a 7 day rest period, plus cisplatin 75 mg/m2 BSA on Day 1 each 28 day cycle Number of Cycles: until progression or unacceptable toxicity develops. Treatment with cisplatin is limited to a maximum of 8 cycles. intervention 2: 5-FU: 800 mg/m2 BSA/24 hours by continuous intravenous infusion (CIV) from Days 1 through 5 plus cisplatin 80 mg/m2 BSA on Day 1 each 21 day cycle.

Number of Cycles: until progression or unacceptable toxicity develops. Treatment with cisplatin is limited to a maximum of 8 cycles.

Protocol document: