ABSTRACT Aim To assess biomarker testing utilization, treatment patterns, and clinical outcomes in previously treated proficient mismatch repair deficient (pMMR) or non-microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC) patients. Materials & methods Using the iKnowMed electronic health record database, this study included pMMR/non-MSI-H adult mCRC patients previously treated with standard-of-care (SoC) chemotherapies between 1 January 2016 and 31 December 2021.