Phase II clinical trial for prevention of delayed diarrhea with cholestyramine/levofloxacin in the second-line treatment with irinotecan biweekly in patients with metastatic colorectal carcinoma

Background: Irinotecan is an established therapeutic option in colorectal cancer. An essential side effect of irinotecan treatment is the induction of severe WHO grade 3-4 delayed diarrhea in up to 25% of treated patients. The aim of the study is the prevention of delayed diarrhea with cholestyramine/levofloxacin. Patients and Methods: Fifty-one patients with a mean age of 64 years (range: 41-81 years) with metastatic colorectal cancer in second-line treatment were included. A cycle corresponds to 4 applications of irinotecan 250 mg/m(2), every 2 weeks, then a break of 2 weeks. Results: After 1 treatment cycle 12% of patients achieved a partial response, 59% had stable disease and 29% progressive disease. Twenty-two patients received a second or more cycles to a total of 379 applications. Forty patients did not develop diarrhea whereas 11 patients had WHO 1-2 diarrhea after at least 1 application of chemotherapy. Diarrhea WHO 3 occurred in only 1 patient (2%) whereas severe diarrhea WHO 4 did not occur. Conclusion: The combination of cholestyramine/levofloxacin is a promising option for the prevention of delayed diarrhea caused by irinotecan. This prophylactic regime may help in future to escalate the dose of irinotecan as a monotherapy or in combination protocols. Copyright (c) 2007 S. Karger AG, Basel.