Final analysis of survival outcomes in the KSCC1501A trial of up-front therapy for HER2-negative advanced gastric cancer

Abstract

Background: According to the results of the randomized phase III study, G-SOX, the combination of S-1 and oxaliplatin (SOX) is as effective as the combination of S-1 and cisplatin for the treatment of HER2-negative advanced gastric cancer (AGC), and also has a favorable safety profile. In this trial, the dose of oxaliplatin tested was 100 mg/m2; however, the dose of 130 mg/m2 is covered by insurance in Japan, based on the results of the pivotal global study. Therefore, the efficacy and safety of the SOX regimen with oxaliplatin 130 mg/m2 (SOX130) remains to be elucidated. In this study, we conducted the final analysis of the survival outcomes in a phase II trial to assess the efficacy and safety of SOX130 in HER2-negative AGC. Method(s): Patients with HER2-negative AGC or recurrent gastric cancer received 80 mg/m2 S-1 per day orally on days 1-14, and 130 mg/m2 oxaliplatin intravenously, on day 1 of each 21-day cycle, until criteria for treatment withdrawal were fulfilled. The primary endpoint was the response rate (RR), and the secondary endpoints were progression-free survival (PFS) and overall survival (OS). Adverse events (AE) were recorded according to CTCAE version 4.0. Result(s): In this study, 71 patients were enrolled from June 2015 to November 2016, but 8 patients were excluded owing to ineligibility. Therefore, the efficacy and safety analyses were finally conducted among 63 patients. The confirmed RR, assessed by an independent review committee, was 46.0% (95% confidence interval CI]: 34.3-58.2), and the disease control rate was 77.8% (95% CI: 66.1-86.3). The median PFS and OS were 4.9 months (95% CI: 4.2-7.1) and 14.8 months (95% CI: 11.1-18.9), respectively. The incidence rates of grade 3 or 4 AE were as follows: neutropenia, 9.5%; thrombocytopenia, 11.1%; anemia, 6.3%; sensory neuropathy, 12.7%; anorexia, 19.0%; and diarrhea, 6.3%. Conclusion(s): SOX130 showed favorable survival outcomes and an acceptable safety profile in the treatment of HER2-negative AGC.Copyright © 2019 European Society for Medical Oncology