Vitamin E Combined With Fruquintinib and Tislelizumab in Microsatellite Stabilized Metastatic Colorectal Cancer Patients

The goal of this clinical trial is to learn about efficacy of Vitamin E in combination with Fuquinitinib and Tirelizumab in patients with microsatellite stabilized mCRC who have failed standard therapy. The main question is to explore the survival time, safety and tolerability of the treatment. At the same time, the correlation between biomarkers (including PD-L1 expression, tumor mutation load, lymphocyte subpopulation, cytokines, TCR, intestinal microbes, and others) and the efficacy and drug resistance mechanism will be analyzed, so as to provide reference for the subsequent guidance of the screening of benefit groups.