Phase II trial of capecitabine/irinotecan and capecitabine/oxaliplatin in advanced gastrointestinal cancers

Combination protocols of 5-fluorouracil/leucovorin (5-FU/LV) plus irinotecan or oxaliplatin have demonstrated high activity in metastatic colorectal cancer. Capecitabine, an oral 5-FU prodrug, may replace infusional 5-FU/LV in combination protocols with irinotecan or oxaliplatin. We therefore initiated a phase II study with capecitabine plus either irinotecan or oxaliplatin to determine the efficacy and toxicity of specific combination protocols in patients with advanced gastrointestinal (GI) tumors. Capecitabine 1000 mg/m² taken orally twice a day on days 1-14, plus oxaliplatin 70 mg/m² on days 1 and 8, or irinotecan 100 mg/m² on days 1 and 8; repeated every 3 weeks in an outpatient setting. Patient and tumor characteristics were as follows: median age, 68 years (range, 34-77 years); sex: 10 women, 33 men; tumor types: 35 colorectal cancer; 8 other GI tumors including 5 gastric, 2 pancreatic, and 1 duodenal cancer. All 43 patients treated were evaluable for toxicity (capecitabine/oxaliplatin, 24 patients; capecitabine/irinotecan, 19 patients), and 39 were evaluable for efficacy (capecitabine/oxaliplatin, 22; capecitabine/irinotecan, 17). Grade 3/4 toxicities (National Cancer Institute Common Toxicity Criteria Version 2.0) were limited to diarrhea, 9 patients (capecitabine/irinotecan, n = 5; capecitabine/oxaliplatin, n = 4); hand-foot syndrome, 1 patient (capecitabine/irinotecan); nausea, 2 patients (capecitabine/oxaliplatin); vomiting, 1 patient (capecitabine/oxaliplatin); and peripheral neuropathy, 1 patient (capecitabine/oxaliplatin). No grade 3/4 myelosuppression was noted for either protocol. Capecitabine/irinotecan and capecitabine/oxaliplatin demonstrated significant clinical activity in colorectal cancer and other GI cancers as first-line and salvage therapy. Capecitabine/oxaliplatin and capecitabine/irinotecan show an excellent safety profile and clinical activity in colorectal cancer and other advanced GI tumors.The main toxicity in both arms was manageable diarrhea.This trial served as basis for a randomized multicenter phase II study comparing capecitabine/oxaliplatin and capecitabine/irinotecan as first-line therapy in patients with advanced colorectal cancer.