Background: FOLFOXIRI plus bevacizumab has demonstrated a survival benefit compared with FOLFIRI plus bevacizumab (TRIBE Lancet Oncol 2015) in first-line mCRC. This schedule is not routinely recommended in all patient groups due to toxicity. VISNÚ-1 trial compared FOLFOX + Bevacizumab (arm A) vs FOLFOXIRI + Bevacizumab (arm B) in non-elderly patients(p) with ≥ 3CTCs at baseline as a poor prognostic factor. Preliminary safety analysis is presented here. Methods: This is an open, multicentric, randomized phase III trial. Patients aged ≤ 70 years, ECOG 0-1 were randomized to arm A or arm B, stratified per KRAS mutation. The data presented here were generated from a snapshot of the database from Oct-31^st-2017. Results: 350 p have been included in the study, 347 p were available for safety analysis. General characteristics in arms A and B: Median age (59 vs 60.5 years), gender (Male/Female: 67.2/32.8 vs 69.4/30.1%), ECOG 0/1 (48/52 vs 47/53%), primary tumor unresected (32.2 vs 37.1%), previous adjuvant chemotherapy (4.0 vs 5.3%). Most common grade ≥3 toxicities and treatment modifications are shown in table 1. Only neutropenia, asthenia, diarrhea and mucositis were more frequent in arm B. Fourteen patients dead due to treatment-related adverse events (6 in the FOLFOX- BEV arm and 8 in the FOLFOXIRI-BEV arm): 7 sepsis, 5 bowel perforation, 2 pulmonary toxicity). Conclusions: In our study, the use of FOLFOXIRI + Bev in mCRC did not result in an increase in treatment delays, dose reductions or treatment interruptions as compared with FOLFOX+Bev despite an increased incidence of neutropenia, diarrhea, asthenia and mucositis. Clinical trial information: NCT01640405