An Open-Label, Multicenter, Randomized, Phase 3 Study of S-1 and Cisplatin compared with 5-FU and Cisplatin in patients with metastatic diffuse gastric cancer previously untreated with chemiotherapy - ND

INTERVENTION: Trade Name: TS‐1 Pharmaceutical Form: Capsule, hard INN or Proposed INN: Tegafur, combinations Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 15‐ Trade Name: TS‐1 capsule 20 Pharmaceutical Form: Capsule, hard INN or Proposed INN: Tegafur, combinations Concentration unit: mg/ml milligram(s)/millilitre Concentration type: equal Concentration number: 20‐ Trade Name: 5‐FU medac (5 ‐fluoracil) Pharmaceutical Form: Solution for injection INN or Proposed INN: Fluorouracil Concentration unit: mg/ml milligram(s)/millilitre Concentration type: equal Concentration number: 50‐ Pharmaceutical Form: Concentrate for solution for infusion INN or Proposed INN: Cisplatin Concentration type: equal Pharmaceutical Form: Concentrate for solution for injection INN or Proposed INN: Cisplatin Concentration type: equal CONDITION: metastatic diffuse gastric cancer ; MedDRA version: 9.1 Level: LLT Classification code 10063916 PRIMARY OUTCOME: Main Objective: To compare the following endpoints for the S‐1/cisplatin regim (experimental arm) with the 5 FU/cisplatin regim(control arm) in patients with metastatic diffuse gastric casncer: overall survival )OS) Primary end point(s): Overall Survival (OS) Survival is the primary endpoint of this study and is defined as the time from date of randomization to date of death. In the absence of death confirmation or for alive at the time of analisys, survival time will be censored at the date of last study follow‐up, or the cut‐off date, whichever is earlier. Secondary Objective: To copmpare the following endpoints for the S‐1/cisplatin regim (experimental arm) with the 5 FU/cisplatin regim(control arm) in patients with metastatic diffuse gastric casncer: ‐ Progression‐free survival (PFS) • Time to treatment failure (TTF) • Safety and tolerability Other Secondary • Antitumor activity: Overall Response Rate (ORR), duration of response (DR), time to tumor response (TTR) • Clinical benefit: Change in performance status (PS), body weight, and anorexia • Healthcare utilization INCLUSION CRITERIA: A patient must meet all of them following inclusion criteria to be eligible for enrollment in this study: 1. Has given written informed consent. 2. Has histologically confirmed by Central Pathology Review, unresectable, metastatic diffuse gastric cancer including carcinoma of the gastro‐esophageal junction. Patients must only be randomized after central pathology review has confirmed diffuse histologic type. Gastro‐esophageal junction involvement must be documented by endoscopic, radiologic, surgical or pathology report. 3. Has had no prior chemotherapy for gastric cancer; however, adjuvant and/or neo‐adjuvant chemotherapy is permitted if more than 12 months have elapsed between the end of adjuvant or neo‐adjuvant therapy and first recurrence. 4. Has a life expectancy of at least 3 months. 5. Is able to take medications orally. 6. Is =18 years of age. Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18‐