Background: FOLFOX7 is an oxaliplatin FOLFOX regimen without 5FU bolus, first used in the OPTIMOX1 MCRC study (Tournigand, JCO 2006). Modified (m) FOLFOX7 has a reduced dose of oxaliplatin (100 mg/m²) and has been used in the OPTIMOX2 trial (Chibaudel, JCO 2009). XELOX2 derived from the bi-weekly XELOX regimen with oxaliplatin 85 mg/m² (Scheithauer, JCO 2003). Methods: First-line induction therapy (IT) allocation was randomized in unresectable MCRC patients with performance status (PS) 0-1 between 6 cycles of mFOLFOX7 with bevacizumab (B) or 6 cycles of XELOX2 with B. Stratification criteria were: center, age, ECOG PS, number of metastatic sites and LDH level. After 3-month IT, a second randomization for maintenance therapy allocation was done in non-progressive patients between B or B-erlotinib. mFOLFOX7-B consisted in B 5 mg/kg followed by folinic acid (FA) 400 mg/m² and oxaliplatin 100 mg/m² followed by 5-flurouracil (5FU) 2,400 mg/m² 46h-infusion. XELOX2-B consisted in B 5 mg/kg followed by oxaliplatin 100 mg/m² followed by capecitabine 1,250 mg/m² twice daily for seven days. Cycles were repeated every two weeks. The objective was to compare the safety and efficacy of XELOX2-B to mFOLFOX7-B (secondary objective of the study). Results: 156 patients were randomized to mFOLFOX7-B and 154 to XELOX2-B. Medians (mFOLFOX7/XELOX2) were: PFS 7.9/8.7 months (HR 0.98, CI 0.74-1.31; p=0.918), OS 26.6/23.4 months (HR 1.24, CI 0.98-1.59; p=0.075). RR (mFOLFOX7/XELOX2) was 50.0%/49.3%. Main grade 3/4 toxicities (mFOLFOX7/XELOX2) were neutropenia 9.2%/2.6% (p=0.018), diarrhea 5.2%/18.3% (p<0.001), asthenia 2.6%/11.8% (p=0.003), all 27.5%/37.6% (p=0.068). Conclusions: Both regimens have the same activity as the parent regimens with a reduced toxicity, especially mFOLFOX7-B. These regimens could be good backbones for future combinations with other agents and are well suited for frail and elderly patients. Clinical trial information: NCT00265824