FOLFOXIRI + Bev + Atezo vs FOLFOXIRI + Bev as First-line Treatment of Unresectable Metastatic Colorectal Cancer Patients

This is a prospective, open-label, multicentric phase II randomized in a 1:2 ratio trial in which patients initially unresectable and previously untreated mCRC will receive induction treatment with FOLFOXIRI plus bev up to 8 cycles followed by maintenance with 5-FU/LV plus bev until disease progression, unacceptable toxicity or patient's refusal (arm A) versus FOLFOXIRI plus bev plus atezolizumab up to 8 cycles followed by maintenance with 5-FU/LV plus bev plus atezolizumab until disease progression, unacceptable toxicity or patient's refusal (arm B). If disease progression does not occur during induction, at the treating physician's discretion, the reintroduction after progression of the same induction treatment (up to 8 cycles) according to randomization arm, followed by maintenance until disease progression, unacceptable toxicity or patient's refusal, is recommended. The third- and subsequent lines of treatment will be at investigators' choice.