Phase II study of S-1 plus docetaxel as first-line treatment for elderly patients with advanced gastric cancer (OGSG0902).

Abstract

129 Background: There is not enough evidence for the treatment of elderly patients with advanced gastric cancer. S-1 plus CDDP is one of the standard treatment for advanced gastric cancer in japan, but the efficacy remains insufficient due to the drug toxicity such as renal function disorders. The efficacy and safety of S-1 plus docetaxel as first-line treatment for elderly patients with unresectable advanced or recurrent gastric cancer were investigated. Methods: 75 years or older patients with unresectable advanced or recurrent gastric cancer were enrolled. Docetaxel was administered i.v. (40mg/m2) on day 1, while S-1 was administered orally (80mg/m2/day, b.i.d.) for 14 days followed by a 7-day rest. This schedule was repeated every 3 weeks. The primary endpoint was response rate (RR) of S-1 plus docetaxel; secondary endpoints were safety, progression free survival (PFS), time to treatment failure (TTF) and overall survival (OS). Sample size was set to be 30, which was determined to reject the response rate of 20% under the expectation of 40% with the power of 90% and two-sided alpha of 5%. Results: 31 patients were enrolled and assessable for efficacy. The response rate was 45.2% (95%CI 27.3-64.0, p = 0.001), and disease control rate was 77.4%. The median progression-free survival time was 5.8 months, the 1-year survival rate was 58.1%, and the median survival time was 16.1months. In 31 patients assessed for safety, the major grade 3/4 toxic effects were neutropenia (58%), febrile neutropenia (13%), anemia (10%), anorexia (10%), and fatigue (6%). Conclusions: These findings indicate that S-1 plus docetaxel as first-line treatment for elderly patients is feasible and shows promising efficacy against advanced gastric cancer. Clinical trial information: UMIN000002785.