Commentary on a phase III trial of bevacizumab plus XELOX or FOLFOX4 for first-line treatment of metastatic colorectal cancer: the NO16966 trial

Replacing infusional 5-fluorouracil (5-FU) leucovorin (LV) with oral capecitabine would be more convenient to patients, because it would lead to reduced hospital chair time and infusion-related toxicities. Previous trials with oral capecitabine-based regimens (other than XELOX capecitabine/oxaliplatin]) have failed to demonstrate the equivalent efficacy of capecitabine based regimens to various 5-FU/oxaliplatin regimens (nonstandard FOLFOX 5-FU/LV/oxaliplatin] combinations); of note, these trials did not use the XELOX and standard FOLFOX regimens. An international phase III trial (NO16966) was initiated to demonstrate the noninferiority of XELOX to FOLFOX4 for the first-line treatment of metastatic colorectal cancer. The protocol was later amended to compare bevacizumab and chemotherapy versus placebo and chemotherapy. The efficacy data showed that XELOX was as effective as FOLFOX4 (progression-free survival PPS; intent-to-treat population]: hazard ratio HR], 1.04; 97.5% confidence interval, 0.93-1.16). Also, bevacizumab/chemotherapy(pooled with XELOX or FOLFOX) significantly prolonged PPS (HR 0.83; p=0.0023) compared with placebo and chemotherapy (XELOX/FOLFOX). In subgroup analysis, the addition of bevacizumab to XELOX (9.3 months vs. 7.4 months. HR.0.77; P=0.0026) and FOLFOX4(9.4 months vs. 8.6 months; HR, 0.89; P = 0.1871) prolonged PFS compared with respective placebo arms; however, it did not show statistical significance with the FOLFOX4 regimen. The adverse events were manageable and comparable between treatment arms.