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

Purpose: 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).
Methods: 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.
Results: 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.
Conclusions: 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.