Phase 2 Trial of Oral S-1 Combined with Low-dose Cisplatin for Unresectable Advanced Pancreatic Cancer

Objectives: A phase 2 trial of S-1 combined with cisplatin was conducted for unresectable pancreatic cancer. Patients and Methods: S-1 was administered for 28 days followed by a rest of 14 days. Cisplatin was infused on days 1-5, 8-12, 15-19 and 22-26 of the first course. After the second course, S-1 was administered as maintenance chemotherapy. Results: Thirty patients were enrolled and the responses observed were 0 complete response, 5 partial response, 22 stable disease and 3 progressive disease, with an overall response rate of 17% (95% confidence internal (CI), 6-35%). Toxicity was tolerable, with grade 3 toxicities observed for leukocytopenia (10%), neutropenia (7%), anemia (3%), thrombocytopenia (3%), anorexia (13%), and nausea and vomiting (7%). The median survival time (MST) and the 1-year survival rate were 9.0 months (95% CI, 6.0-14.5 months) and 35.7% (95% CI, 19-55%), respectively. Conclusion: S-1 with low-dose cisplatin is well tolerated and effective for advanced pancreatic cancer.