Capecitabine plus 3-weekly irinotecan (XELIRI regimen) as first-line chemotherapy for metastatic colorectal cancer - Phase II trial results

Background: Capecitabine results in superior response rate, improved safety, and improved convenience compared with 5-fluorouracil (FU)/leucovorin (LV) in metastatic colorectal cancer (MCRC). Irinotecan in combination with 5-FU/LV has been shown to improve efficacy compared with 5-FU/LV alone in MCRC. Therefore, we evaluated the efficacy and safety of capecitabine plus irinotecan every 3 weeks (XELIRI regimen) as first-line treatment. Methods: Patients with MCRC who were <65 years of age received irinotecan 250 mg/m(2) i.v. on day 1 + capecitabine 1000 mg/m2 orally twice daily on days I to 14, every 3 weeks. Patients >= 65 years of age and those with impaired renal function or with a history of prior radiotherapy received lower doses of both agents (200 mg/m2 and 750 mg/m2 twice daily, respectively). Results: A total of 52 patients (29 men, 23 women) were enrolled between October 2001 and August 2003. Median age was 57.5 years (range, 30-79 years); median Kamofsky performance status was 90 (range, 70-100). Treatment led to a response rate of 50% (ITT population) and a disease control rate of 71%. With a median cohort follow-up of 30.5 months, median time to progression and overall survival are 7.8 months (95% confidence interval, 5.6-10.0) and 16.8 months (95% confidence, 11.9 to not reached), respectively. Most common treatment-related grade 3/4 adverse events were neutropenia (25%), diarrhea (20%), vomiting (16%), dehydration (10%), nausea (6%), abdominal pain (6%), and hand-foot syndrome (6%). Conclusion: XELIRI is an active first-line treatment of MCRC. Implementation of upfront dose reductions for both agents in patients with risk factors for toxicity appears to have produced a safer regimen compared with previous studies of XELIRI without such dose reductions.