Phase II study of weekly irinotecan and capecitabine treatment in metastatic colorectal cancer patients

BACKGROUND: The purpose of this phase II study was to evaluate the safety and efficacy of weekly irinotecan and capecitabine (wXELIRI) treatment in patients with metastatic colorectal cancer, specifically the rate of severe diarrhea. METHODS: Patients with unresectable histologically confirmed metastatic colorectal cancer with measurable disease received weekly irinotecan 90 mg/m(2) on day 1 and capecitabine 1200 mg/m(2) twice daily on days 1–5. Patients naïve to systemic chemotherapy for metastatic disease or who had failed FOLFOX (infusional 5-fluorouracil [5-FU], leucovorin, and oxaliplatin) or XELOX (capecitabine plus oxaliplatin) as first-line treatment were eligible. The primary endpoint was the rate of grade 3/4 diarrhea. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. RESULTS: A total of 52 patients were enrolled, 30 of whom received wXELIRI as first-line treatment and 22 as second-line treatment. Grade 4 diarrhea was observed in one patient and the rate of grade 3/4 diarrhea was 7.7%. The other common grade 3/4 toxicities included leukopenia (9.6%), neutropenia (17.3%), nausea (3.8%), vomiting (3.8%), fatigue (1.9%), and hand-foot syndrome (1.9%). The median progression-free survival and overall survival for the 30 patients treated in the first-line setting was 8.5 and 16.3 months, while those for the 22 patients treated in the second-line setting was 5.0 and 10.7 months, respectively. CONCLUSIONS: The wXELIRI regimen resulted in a low rate of severe diarrhea with an acceptable toxicity profile. This study provides a basis for a subsequent randomized controlled study of wXELIRI versus FOLFIRI (irinotecan, 5-FU, and folinic acid) to further explore the efficacy and safety of this regimen. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01322152.