Oxaliplatin plus irinotecan compared with irinotecan alone as second-line treatment after single-agent fluoropyrimidine therapy for metastatic colorectal carcinoma

Purpose To determine whether irinotecan plus oxaliplatin (IROX) is superior to irinotecan alone in patients with metastatic colorectal cancer (CRC) previously treated with single-agent fluoropyrimidines. Patients and Methods A phase III, randomized, open-label, multicenter study of patients with metastatic or recurrent CRC that had progressed or recurred during or after adjuvant or first-line fluoropyrimidines (fluorouracil/leucovorin or capecitabine, the latter only for metastatic CRC). Patients received IROX (irinotecan 200 mg/m(2) plus oxaliplatin 85 mg/m(2)) or irinotecan alone (350 mg/m(2)) every 3 weeks. Results At the data cutoff (when 447 of 628 randomly assigned patients had died), median overall survival was 13.4 months (95% CI, 12.4 to 14.7 months) and 11.1 month (95% CI, 10.0 to 12.7 months) in the IROX and irinotecan groups, respectively (hazard ratio = 0.78; 95% CI, 0.65 to 0.94; P = .0072). Overall response rate (22% v 7%, respectively; P < .0001), median time to progression (5.3 v 2.8 months, respectively; P < .0001), and improvement in tumor-related symptoms (32% v 19%, respectively; P < .0072) were also improved with IROX as compared with irinotecan. With the exception of granulocytopenia (25% v 13%), diarrhea (28% v 23%), and sensory disturbances (5% v 0%), grade 3 to 4 toxicities were comparable between the IROX and irinotecan groups, respectively. Conclusion IROX is an effective treatment for metastatic CRC that has progressed after first-line fluoropyrimidine therapy. IROX improves efficacy compared with irinotecan alone, providing an additional option in the postadjuvant or second-line treatment setting for patients who experience treatment failure with single-agent fluoropyrimidine therapy.