PRIMARY OBJECTIVES:~This preliminary prospective study aims to evaluate the safety of neoadjuvant treatment combination of Sintilimab, XELOX and bevacizumab and also asses safety during surgery of colorectal patients with liver metastasis and pMMR/MSS status.~SECONDARY OBJECTIVES:~To evaluate Pathological Remission Rate (pCR/MPR/PR rate), Objective Response Rate (ORR), Recurrence Free Survival (RFS) and Overall Survival (OS).~EXPLORATORY OBJECTIVES:~Analysis of liver metastasis before and after treatment to compare molecular and immunophenotypic changes.~OUTLINE:~Patients receive Sintilimab + XELOX regimen every 3 weeks for 4 cycles and Bevacizumab every 3 weeks for 2 cycles. After which if there are no new lesions upon assessment, radical surgery is performed within 6 weeks after neoadjuvant treatment. After surgery 4 cycles of XELOX regimen is advised for adjuvant therapy.
This prospective, single arm study aims to evaluate the preoperative neoadjuvant safety of Sintilimab combined with XELOX plus bevacizumab in colorectal patients with liver metastasis and pMMR/MSS status.