On the Herceptin-containing arm, Herceptin was administered as an IV infusion at an initial dose of 8 mg/kg followed by 6 mg/kg every 3 weeks until disease progression. On both study arms cisplatin was administered at a dose of 80 mg/m2 Day 1 every 3 weeks for 6 cycles as a 2 hour IV infusion. On both study arms capecitabine was administered at 1000 mg/m2 dose orally twice daily (total daily dose 2000 mg/m2) for 14 days of each 21 day cycle for 6 cycles. Alternatively continuous intravenous infusion (CIV) 5-fluorouracil was administered at a dose of 800 mg/m2/day from Day 1 through Day 5 every three weeks for 6 cycles.

The median age of the study population was 60 years (range: 21-83); 76% were male; 53% were Asian, 38% Caucasian, 5% Hispanic, 5% other racial/ethnic groups; 91% had ECOG PS of 0 or 1; 82% had primary gastric cancer and 18% had primary gastroesophageal adenocarcinoma. Of these patients, 23% had undergone prior gastrectomy, 7% had received prior neoadjuvant and/or adjuvant therapy, and 2% had received prior radiotherapy.

The main outcome measure of Study 7 was overall survival (OS), analyzed by the unstratified log-rank test. The final OS analysis based on 351 deaths was statistically significant (nominal significance level of 0.0193). An updated OS analysis was conducted at one year after the final analysis. The efficacy results of both the final and the updated analyses are summarized in Table 11 Figure 6.

Figure 6
Updated Overall Survival in Patients with Metastatic Gastric Cancer (Study 7)

An exploratory analysis of OS in patients based on HER2 gene amplification (FISH) and protein overexpre