Tislelizumab in People With Colorectal Cancer

This study is testing an immunotherapy drug called tislelizumab in patients with colorectal cancer. Immunotherapy works by helping the immune system recognize and attack cancer cells, and this trial evaluates how well it works and how safe it is in this cancer type. **You may be eligible if...** - You are 18 years or older - You are in good physical condition (able to carry out normal activities) - You have a confirmed diagnosis of colorectal cancer - Women of childbearing age must have a negative pregnancy test and use contraception **You may NOT be eligible if...** - You are pregnant or breastfeeding - You have serious autoimmune conditions - You have had prior treatment that would make immunotherapy unsafe - Your physical condition is too poor for treatment Talk to your doctor to see if this trial is right for you.