Pooled efficacy analysis from a phase I-II study of biweekly irinotecan in combination with gemcitabine, 5-fluorouracil, leucovorin and cisplatin in patients with metastatic pancreatic cancer

Development of treatments to improve the outcomes achieved with single-agent gemcitabine therapy for metastatic pancreatic cancer remains a research priority. G-FLIP (gemcitabine, 5-fluorouracil, leucovorin and cisplatin) is a four-drug regimen designed to maximize sequence-dependent synergy, while attempting to minimize toxicity among the four drugs. The dose-limiting toxicities and maximum tolerated dose of irinotecan as part of the G-FLIP regimen have been published. For phase II testing, G-FLIP consisted of sequential gemcitabine 500 mg/m2 at a fixed rate of 10 mg/m2/min, irinotecan 120 mg/m2, bolus 5-fluorouracil 400 mg/m2 and leucovorin 300 mg, followed by a 24-h 5-fluorouracil infusion of 1500 mg/m2 on day 1 and cisplatin 35 mg/m2 on day 2. Cycles were repeated every 14 days. Thirty-three patients with metastatic pancreatic cancer (22 men and 11 women) were treated and 31 were evaluable. Median patient age was 63 years (range 44-78 years) and median Karnofsky performance status score was 70-80. Estimated median time to disease progression was 171 days (6.1 months) and Kaplan-Meir-estimated median overall survival was 229 days (8.1 months). Twelve- and 18-month survivals were 33 and 21%, respectively. As per Response Evaluation Criteria in Solid Tumors criteria, 13 patients had stable disease, seven (22%) attained a partial response, and 10 (32%) had disease progression. One patient attained a complete response and two were not evaluable (one withdrew consent and one died suddenly, each after cycle 1). Treatment generally was well tolerated. Grade 3-4 toxicities/patient were thrombocytopenia (3.1%), leukopenia (15%), neutropenia (21%), neutropenic fever (3%), fatigue (18%) and thrombosis (12.5%). Common grade 1-2 toxicities per patient included nausea/vomiting (69%), diarrhea (45%), constipation (21%) and fatigue (39%). In conclusion, G-FLIP is a feasible outpatient regimen with acceptable toxicity for metastatic pancreatic cancer patients. Disease control rate (stable disease rate plus partial or complete responses) and 1-year survival outcomes are encouraging.