First-line chemotherapy with capecitabine/oxaliplatin for advanced gastric cancer: A phase I study

Combination chemotherapy with capecitabine and oxaliplatin for gastric cancer (G-XELOX) is considered as a potentially promising regimen. However, the use of the G-XELOX regimen in Japanese patients has not been investigated to date, and recommended doses of G-XELOX for Japanese patients with metastatic gastric cancer have not been established. The aim of the present study was to determine the maximum tolerated dose (MTD) and recommended dose (RD) for systemic chemotherapy with G-XELOX for metastatic gastric cancer. The enrolled patients received systemic chemotherapy with oxaliplatin 130 mg/m² on day 1 and capecitabine 2,000 mg/m²/day, b.i.d. for 14 days, repeated every 3 weeks. A decrease in oxaliplatin dose was planned from start level 1 (130 mg/m²). A total of 6 patients were enrolled between January and July 2015. MTD was not reached at level 1. Oxaliplatin 130 mg/m² in combination with capecitabine 2,000 mg/m²/day b.i.d. could be administered with acceptable toxicity, and all patients were treated at these doses. One case of grade 3 stomatitis was considered as a dose-limiting toxicity at level 1; however, excluding this case, no grade 3 or 4 non-hematological toxicity was observed. There were no treatment-related deaths. The median relative dose intensity was 71.3% for capecitabine and 92.1% for oxaliplatin. Of the 6 patients, 3 had measurable lesions according to the Response Evaluation Criteria In Solid Tumors; the response rate and disease control rate were both 67%. Therefore, systemic chemotherapy with G-XELOX was well-tolerated by patients with advanced gastric cancer. The RD was defined as oxaliplatin 130 mg/m² in combination with capecitabine 2,000 mg/m²/day b.i.d.