Abstract
BACKGROUND: Chemotherapy with SOX (S-1 and oxaliplatin) regimen showed good efficacy and a favorable safety profile in advanced gastric cancer. Anti-programmed cell death protein 1 (PD-1) antibody camrelizumab also demonstrated antitumor activity in this setting in a phase I study. However, the efficacy and safety of camrelizumab plus SOX for advanced gastric cancer have not been investigated. Thus, this study aimed to address this objective. METHODS: This phase II study evaluated the efficacy and safety of camrelizumab plus SOX in previously untreated advanced gastric cancer. Patients received camrelizumab (200 mg intravenously every 3 weeks) plus SOX (S-1, 40 mg/m(2) orally twice daily on days 1-14; oxaliplatin, 130 mg/m(2) intravenously on day 1 every 3 weeks) until disease progression, death, or intolerable toxicity. Camrelizumab was prescribed for up to a year. The primary endpoint was progression-free survival (PFS). The second endpoints were overall survival (OS), objective response rate (ORR), and disease control rate (DCR). RESULTS: A total of 25 patients were enrolled and received at least 1 dose of study drug. The median PFS was 7.4 months [95% confidence interval (CI): 5.6-16.4]. The median OS was 20.2 months (95% CI: 10.5-29.9); ORR was 36% (95% CI: 18.0-57.5%); DCR was 92% (95% CI: 74.0-99.0%). Among the 25 patients, 22 (88%) experienced any-grade adverse events (AEs), and 7 (28%) patients experienced grade ≥3 AEs. CONCLUSIONS: Camrelizumab plus SOX showed promising efficacy and an acceptable safety profile as the first-line treatment for advanced gastric cancer.