Phase II study of S-1 plus oxaliplatin 130 mg/m 2 in Japanese patients with advanced gastric cancer.

Purpose: Although oxaliplatin 130 mg/m ² every 3 weeks was approved for advanced gastric cancer in Japan, data regarding S-1 plus oxaliplatin 130 mg/m ² (SOX130) are limited in Japanese patients with advanced gastric cancer. We investigated the feasibility and safety of SOX130 in Japanese patients with advanced gastric cancer.
Methods: Patients with unresectable or recurrent gastric adenocarcinoma, no previous chemotherapy, and Eastern Cooperative Oncology Group Performance Status of 0-1 were treated with SOX130. The primary endpoint was the 3-cycle completion rate, defined as the proportion of patients who completed the first three cycles with ≥ 80% relative dose intensity of oxaliplatin.
Results: Twenty-five patients were enrolled from April 2015 to 2016. The 3-cycle completion rate was 72.0% (90% confidence interval: 53.8-86.1), which was higher than the predetermined threshold rate of 50%. With the median number of cycles being 6 (range, 1-19+), grade 3 or 4 adverse events occurred in 10 patients (40%). Major grade 3 adverse events were anorexia (24%), thrombocytopenia (16%), and neutropenia (12%). No febrile neutropenia or treatment-related deaths occurred. Among 12 patients with measurable lesions, the overall response rate was 58.3%. Median progression-free and overall survival were 5.7 months (95% confidence interval 2.9-8.5) and 13.1 months (95% confidence interval 7.4-19.0), respectively.
Conclusion: Results indicated that SOX130 was feasible in Japanese patients with advanced gastric cancer.