Efficacy and Safety of AK104 Combined With Chemotherapy and Cetuximab or Bevacizumab

This study tests a combination of AK104 (a dual checkpoint inhibitor targeting both PD-1 and CTLA-4), chemotherapy, and either cetuximab or bevacizumab as a second-line treatment for patients with metastatic colorectal cancer that is not driven by certain resistance mutations. The goal is to see if adding this immune therapy improves outcomes after first-line treatment has failed. **You may be eligible if...** - You are between 18 and 75 years old - You have confirmed metastatic colorectal cancer that cannot be surgically removed - Your cancer is MSI-L or MSS type (not microsatellite unstable) - You have only received one prior line of oxaliplatin-based chemotherapy (such as FOLFOX or CAPOX) - You have at least one measurable tumor - Your organ function meets the required thresholds - Your expected survival is at least 3 months **You may NOT be eligible if...** - Your cancer has MSI-H or dMMR status, or a BRAF mutation - You have another cancer in the past 3 years - You have previously received any immunotherapy (such as anti-PD-1 or anti-CTLA-4 drugs) - You have an active autoimmune disease or a history of inflammatory bowel disease - You have HIV, uncontrolled hepatitis B or C, or active tuberculosis - You have had a major surgery or serious infection within the past 4 weeks Talk to your doctor to see if this trial is right for you.