Efficacy and Safety of S-1 Plus Oxaliplatin in Advanced Gastric Cancer: A Randomized Phase III Study

Researchers at the University of Tsukuba in Japan have published a study evaluating the efficacy and safety of S-1 plus oxaliplatin (SOX) as an alternative to cisplatin plus S-1 (CS) in first-line chemotherapy for advanced gastric cancer. The study, which involved 685 patients, found that SOX was noninferior to CS in terms of progression-free survival and overall survival, with a favorable safety profile.

Key Takeaways:

• The study involved 685 patients with advanced gastric cancer who were randomly assigned to receive either SOX or CS.
• The primary end points were noninferiority in progression-free survival (PFS) and relative efficacy in overall survival (OS) for SOX using adjusted hazard ratios (HRs) with stratification factors.
• In the per-protocol population, SOX was noninferior to CS in PFS [median, 5.5 versus 5.4 months; HR 1.004, 95% confidence interval (CI) 0.840-1.199; predefined noninferiority margin 1.30].
• The median OS for SOX and CS were 14.1 and 13.1 months, respectively (HR 0.958 with 95% CI 0.803-1.142).
• The most common grade 3 adverse events (SOX versus CS) were neutropenia (19.5% versus 41.8%), anemia (15.1% versus 32.5%), hyponatremia (4.4% versus 13.4%), febrile neutropenia (0.9% versus 6.9%), and sensory neuropathy (4.7% versus 0%).

Sources:

• Phase III study comparing oxaliplatin plus S-1 with cisplatin plus S-1 in chemotherapy-naive patients with advanced gastric cancer. Annals of Oncology, 2015;26(1):141-148.