Safety and Efficacy of Fruquintinib Plus Chidamide and Sintilimab in the Third and Later Line Treatment of MSS/pMMR Metastatic Colorectal Cancer

This study tests a three-drug combination (fruquintinib, chidamide, and sintilimab) in people with advanced colorectal cancer that hasn't responded to standard treatments and is classified as microsatellite stable (MSS) — a type that typically doesn't respond well to immunotherapy alone. **You may be eligible if...** - You are 18–75 years old - You have been diagnosed with advanced or metastatic colorectal cancer (confirmed by biopsy) - Your cancer has not responded to at least two prior rounds of standard treatment - Your tumor has been tested and confirmed as MSS or pMMR (a specific molecular profile) - Your heart, liver, and kidney function meet the required levels - You are physically functional (ECOG 0–2) **You may NOT be eligible if...** - You are pregnant or breastfeeding - You have uncontrolled heart disease or high blood pressure - You have previously been treated with tyrosine kinase inhibitors or immune checkpoint drugs for metastatic disease - You are allergic to any of the study drugs - You have active HIV or active hepatitis B or C Talk to your doctor to see if this trial is right for you.