BACKGROUND: Only a few clinical trials have been conducted in patients with advanced pancreatic cancer after failure of first-line gemcitabine-based chemotherapy. Therefore, there is no current consensus on the treatment of these patients. We conducted a randomised phase II study of the modified FOLFIRI.3 (mFOLFIRI.3; a regimen combining 5-fluorouracil (5-FU), folinic acid, and irinotecan) and modified FOLFOX (mFOLFOX; a regimen combining folinic acid, 5-FU, and oxaliplatin) regimens as second-line treatments in patients with gemcitabine-refractory pancreatic cancer. METHODS: The primary end point was the 6-month overall survival rate. The mFOlFIRI.3 regimen consisted of irinotecan (70 mg m Ă2 ; days 1 and 3), leucovorin (400 mg m Ă2 ; day 1), and 5-FU (2000 mg m Ă2 ; days 1 and 2) every 2 weeks. The mFOLFOX regimen was composed of oxaliplatin (85 mg m Ă2 ; day 1), leucovorin (400 mg m Ă2 ; day 1), and 5-FU (2000 mg m Ă2 ; days 1 and 2) every 2 weeks. RESULTS: Sixty-one patients were randomised to mFOLFIRI.3 (n ÂŒ 31) or mFOLFOX (n ÂŒ 30) regimen. The six-month survival rates were 27% (95% confidence interval (CI) ÂŒ 13 -46%) and 30% (95% CI ÂŒ 15 -49%), respectively. The median overall survival periods were 16.6 and 14.9 weeks, respectively. Disease control was achieved in 23% (95% CI ÂŒ 10 -42%) and 17% patients (95% CI ÂŒ 6 -35%), respectively. The number of patients with at least one grade 3/4 toxicity was identical (11 patients, 38%) in both groups: neutropenia (7 patients under mFOLFIRI.3 regimen vs 6 patients under mFOLFOX regimen), asthaenia (1 vs 4), vomiting (3 in both), diarrhoea (2 vs 0), and mucositis (1 vs 2). CONCLUSION: Both mFOLFIRI.3 and mFOLFOX regimens were tolerated with manageable toxicity, offering modest activities as second-line treatments for patients with advanced pancreatic cancer, previously treated with gemcitabine.