Capecitabine plus oxaliplatin (XELOX) versus 5-fluorouracil/leucovorin plus oxaliplatin (FOLFOX-6) as first-line treatment for metastatic colorectal cancer

A regimen consisting of 5-fluorouracil/leucovorin plus oxaliplatin (FOLFOX-6) is widely used in France in the first-line treatment of metastatic colorectal cancer (MCRC). The aim of our study was to demonstrate the non-inferiority of capecitabine plus oxaliplatin (XELOX) versus FOLFOX-6 for this indication. Patients were randomly assigned to receive XELOX or FOLFOX-6 for 6 months. The primary endpoint was overall response rate (ORR) in the per-protocol (PP) population; however, progression-free and overall survival (OS), time to response and response duration were also assessed. A total of 306 patients were enrolled (XELOX n = 156; FOLFOX-6 n = 150). ORR was 42 and 46% with XELOX and FOLFOX-6, respectively, in the PP population. The difference between groups was 4.7%; the upper limit of the unilateral 95% confidence interval (14.4%) was below the non-inferiority margin of 15%. In the intent-to-treat population, median progression-free survival was 8.8 months with XELOX and 9.3 months with FOLFOX-6, and median OS was 19.9 and 20.5 months, respectively. XELOX patients had significantly more grade 3/4 thrombocytopenia (12% vs. 5%) and diarrhoea (14% vs. 7%), but significantly less grade 3/4 neutropenia (5% vs. 47%), febrile neutropenia (0% vs. 6%) and neuropathy (11% vs. 26%) than FOLFOX-6 patients. We conclude that XELOX is non-inferior in terms of efficacy to FOLFOX-6 in the first-line treatment of MCRC, but has a different toxicity profile.