Multicenter phase II study of trastuzumab in combination with capecitabine and oxaliplatin for advanced gastric cancer

Background Trastuzumab has been approved for use in combination with fluoropyrimidine plus cisplatin for the treatment of human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (AGC). Although capecitabine plus oxaliplatin (XELOX) is a standard first-line regimen for AGC, combination trastuzumab plus XELOX has not been studied. Methods Patients with metastatic or unresectable HER2-positive AGC were diagnosed by either HER2 immunohistochemistry (IHC) 3+ or IHC 2+/fluorescence in-situ hybridisation (FISH)+ received intravenous trastuzumab (8 mg/m² for first cycle and 6 mg/m² for subsequent cycles on day 1) plus oral capecitabine (1000 mg/m² twice daily on days 1-14) and intravenous oxaliplatin (130 mg/m² on day 1), every 3 weeks. The primary end-point was the objective response rate, and secondary end-points included progression-free survival (PFS), overall survival (OS) and toxicity profiles. Results Fifty-five HER2-positive AGC patients were enrolled between August 2011 and February 2013. The median age was 57 years (range = 29-74). The confirmed objective response rate was 67% (95% confidence interval (CI) = 54-80%). After a median follow-up period of 13.8 months (range = 6.1-23.9), the median PFS and OS were 9.8 months (95% CI = 7.0-12.6) and 21.0 months (95% CI = 6.4-35.7), respectively. Frequently encountered grade 3-4 toxicities included neutropenia (18%), anaemia (11%), and peripheral neuropathy (11%). There was a treatment-related death caused by severe diarrhoea and complicated sepsis. Conclusion Combination of trastuzumab and XELOX is well tolerated and highly effective in patients with HER2-positive AGC.