Combination Immunotherapy for the Treatment of Chemotherapy-refractory Metastatic MSS CRC

This study is testing a combination of immunotherapy drugs for people with metastatic colorectal cancer (cancer that has spread) that does not respond to immunotherapy on its own — specifically cancer that lacks a marker called MSI-H, which normally makes it more responsive to these drugs. **You may be eligible if...** - Your colorectal cancer has been confirmed by biopsy and is classified as non-MSI-H (microsatellite stable) - Your cancer has progressed or you could not tolerate standard chemotherapy regimens including fluoropyrimidines, oxaliplatin, and irinotecan - You have at least one tumor that can be measured on imaging (at least 10 mm) - You have at least one tumor site accessible for a biopsy - You are willing to provide blood samples at scheduled study visits **You may NOT be eligible if...** - You have not yet tried standard chemotherapy options - You are unable or unwilling to undergo biopsies or blood draws as required - You do not meet organ function or performance status requirements Talk to your doctor to see if this trial is right for you.