A late phase II study of S-1 for metastatic pancreatic cancer

This study evaluated the antitumor effect and safety of S-1, an oral fluoropyrimidine derivative, in patients with metastatic pancreatic cancer. Chemo-naive patients with pancreatic adenocarcinoma, and measurable metastatic lesions were enrolled. S-1 was administered orally twice daily after meals at a dose of 80, 100, or 120 mg/day for body surface areas (BSAs) of less than 1.25 m², between 1.25 m² and less than 1.5, or 1.5 m² or greater, respectively, for 28 consecutive days, followed by a 14-day rest. Fifteen (37.5%) of 40 patients responded to treatment, including 1 complete response and 14 partial responses. The median time to progression and the overall survival time were 3.7 months (95% confidence interval, 2.2–5.6 months) and 9.2 months (95% confidence interval, 7.5–10.8 months), respectively. The major adverse events were anorexia, fatigue, hemoglobin reduction, nausea and pigmentation change, although most were tolerable and reversible. Although disseminated intravascular coagulation occurred in two patients, the condition resolved with anticoagulant therapy. S-1 is an effective and well-tolerated drug. The effectiveness of this drug should be confirmed in a phase III study.