XELOX +Bev +Tislelizumab for First-line Treatment of MSS/pMMR RAS-mutated mCRC

This study is testing a combination of three drugs — XELOX chemotherapy (capecitabine plus oxaliplatin) together with bevacizumab (a drug that blocks blood vessel growth in tumors) and tislelizumab (an immunotherapy drug) — as a first-line treatment for metastatic colorectal cancer that cannot be surgically removed. The cancer must have specific molecular features: MSS/pMMR type (meaning standard immunotherapy alone is not expected to work) and RAS mutations. **You may be eligible if...** - You have confirmed metastatic colorectal cancer with MSS/pMMR and RAS mutation status - You have not previously received chemotherapy for metastatic disease - You have at least one measurable tumor on imaging - You are physically well enough to carry out most daily activities (ECOG 0–1) - Your blood counts and organ function are within required ranges - You are able to swallow oral medications **You may NOT be eligible if...** - Your cancer is resectable (can be surgically removed) - You have already received systemic treatment for metastatic disease - Your tumor is MSI-high (this subtype responds to immunotherapy differently) - You have serious heart or organ disease that would make treatment unsafe - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.