Trastuzumab in combination with capecitabine and oxaliplatin for advanced gastric cancer Multicenter phase II clinical study BACKGROUND: Trastuzumab has been approved for fluorouracil in combination with cisplatin for human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (AGC). Although capecitabine combined with oxaliplatin (XELOX) is the standard first-line treatment regimen for AGC, trastuzumab combined with XELOX regimen has not been studied. Methods: Patients with metastatic or advanced HER2-positive gastric cancer with a diagnosis based on HER2 immunohistochemistry (IHC) 3 +, or IHC 2 + and fluorescence in situ hybridization (FISH) +. The treatment regimen consisted of intravenous trastuzumab (8 mg/m2 first cycle and 6 mg/m2 subsequent cycles, day 1) plus oral capecitabine (1000 mg/m2 twice daily, days 1-14) and intravenous oxaliplatin (130 mg/m2, day 1) in cycles of 3 weeks. The primary endpoint was objective remission rate (ORR), and secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. RESULTS: A total of 55 HER2-positive patients with AGC between August 2011 and February 2013 with a mean age of 57 years (range 29-74 years) were recruited. The objective response rate was 67% (95% confidence interval (CI) = 54-80 %). 13.8 months median follow-up period (6.1-23.9 months) with median PFS and OS of 9.8 months (95% CI = 7.0-12.6) and 21 months (95% CI = 6.4-35.7), respectively. Common grade 3-4 toxic reactions included neutropenia (18%), anemia (11%), and peripheral neuropathy (11%). There was one treatment-related death of severe diarrhea and concurrent sepsis. CONCLUSION: The combination of trastuzumab and XELOX regimen was well tolerated and very effective in HER2-positive AGC patients.