Subjects will be randomized in a 1:1 ratio into either the chidamide + sintilimab + bevacizumab group or the standard second-line FOLFIRI + bevacizumab therapy group. The treatment option for the chidamide + sintilimab + bevacizumab (study group) is 200 mg of sintilimab IV Drip Q3W, 30 mg of chidamide PO BIW, and bevacizumab 7.5 mg/kg IV Drip Q3W, with a maximum treatment duration of 2 years. The treatment option for the standard second-line FOLFIRI + bevacizumab therapy group (control group) is bevacizumab 5 mg/kg IV Drip Q2W, irinotecan 180 mg/m2 IV Drip Q2W, calcium folinate 400 mg/m2 IV Q2W or calcium levofolinate 200 mg/m2 IV Drip Q2W, 5-fluorouracil 400 mg/m2 IV +2400 mg/m2 CIV Q2W, with a maximum treatment duration of 2 years.~The primary endpoint of this study is the progression-free survival (PFS), defined as the time from random assignment of the subject to disease progression or death from any cause.~All eligible patients will be randomly assigned to either the trial or control group in a 1:1 ratio based on the following stratification factors: Whether the primary focus is located in the right-sided colorectum; Whether bevacizumab has been administered in the first-line treatment.
This is a randomized, controlled, multicenter phase Ⅲ study to evaluate the therapeutic efficacy and safety of chidamide + sintilimab + bevacizumab versus standard second-line FOLFIRI + bevacizumab therapy in subjects with advanced microsatellite stable colorectal cancer who have failed first-line oxaliplatin-containing standard therapy. The primary purpose is to compare the progression-free survival (PFS) of chidamide + sintilimab + bevacizumab versus standard second-line FOLFIRI + bevacizumab therapy for colorectal cancer, with a planned enrollment of 176 subjects with advanced microsatellite stable colorectal cancer who have failed first-line oxaliplatin-containing standard therapy.