A phase I trial of gemcitabine, S-1 and LV combination (GSL) therapy in advanced pancreatic cancer.

Abstract

In our previous randomized controlled trial, the addition of S-1 to gemcitabine for advanced pancreatic cancer did not prolong overall survival (OS) significantly, despite its higher response rate and longer progression-free survival (PFS). Leucovorin is known to enhance efficacy of S-1, and we conducted this phase I trial of combination therapy of gemcitabine, S-1 and leucovorin (GSL). Patients with advanced pancreatic cancer who had received no prior chemotherapy were eligible for this study. Gemcitabine was administered at an escalating dose of 600, 800 and 1,000 mg/m(2) over 30 min on day 1, and oral S-1 at a dose of 40 mg/m(2) twice daily and oral leucovorin at a dose of 25 mg twice daily on days 1-7, every 2 weeks. A standard "3 + 3" phase I dose escalation design was utilized. Fifteen patients were enrolled across three dose levels. Three patients developed DLTs: two patients in level 1 (grade 3 anorexia in 1 and grade 3 anorexia, stomatitis and diarrhea in 1) and one patient in level 2 (grade 3 deep vein thrombosis). No DLT was observed in level 3. Response rate and the disease control rate were 33 and 93 %, respectively. The median PFS and OS were 5.4 and 16.6 months. Ten of 12 patients (83 %) with elevated CA19-9 at baseline had a ≥ 50 % decline. RD of gemcitabine in GSL was determined as 1,000 mg/m(2). GSL was well tolerable and showed promising results in advanced pancreatic cancer.