XELOX and Bevacizumab in Combination With Tislelizumab for First-Line Treatment of Patients With MSS/pMMR RAS-mutated Metastatic Colorectal Cancer (mCRC): A Single-arm, Phase II Study.
The goal of this clinical trial is to compare XELOX +Bev +Tislelizumab with standard chemotherapy，in MSS/pMMR-type RAS-mutated metastatic colorectal adenocarcinoma. The main questions it aims to answer are efficacy and safety of the regimen of XELOX +Bev +Tislelizumab. The investigators want to transform ras-mutated colorectal cancer into a hot tumor through the combination of anti-vascular therapy and chemotherapy, and then achieve better therapeutic effect through the combination with immunotherapy. Participants will receive the regimen of XELOX +Bev +Tislelizumab.
• Histologically confirmed initially unresectable MSS/pMMR-type RAS-mutant metastatic colorectal adenocarcinoma;
• ECOG score of 0 or 1;
• Ability to swallow oral medications;
• Have at least one measurable lesion (according to RECIST v1.1 standard);
• No anti-tumor treatment has been received after recurrence and metastasis;
• Neoadjuvant or adjuvant chemotherapy containing fluorouracil drugs is allowed before or after radical resection of colorectal cancer, but the treatment needs to be completed for ≥ 6 months; if oxaliplatin is used in neoadjuvant or adjuvant chemotherapy, it includes The oxaliplatin regimen needs to be completed for ≥12 months;
• Adequate organ function: On the premise of no component blood transfusion within 14 days: white blood cells ≥ 3.5\*10\^9/L and neutrophils ≥ 1.5\*10\^9/L, hemoglobin ≥ 90g/L, platelets ≥ 100\* 10\^9/L; serum bilirubin ≤ 1.5 times the normal value, alanine aminotransferase (ALT) ≤ 2.5 times the normal value, aspartate aminotransferase (AST) ≤ 2.5 times the normal value; Urinary protein \<2+. Or urine protein 2+ but 24-hour urine protein quantity ≤ 1 g; serum creatinine ≤ 1.5 times of normal value, creatinine clearance rate ≥ 60ml/min; Doppler ultrasound evaluation: left ventricular ejection fraction (LVEF) ≥ lower limit of normal value (50%);
• Expected survival period ≥ 3 months;
• Patients fully understand this research, voluntarily participate in this clinical trial and sign an informed consent;
⁃ Women with reproductive potential (\< 2 years after the last menstrual period) and men use effective contraceptive methods until half a year after the last treatment.