Immunotherapy for the treatment of colorectal cancer

Abstract Immune checkpoint inhibition (ICI) has transformed the management of metastatic colorectal cancer (mCRC) with mismatch‐repair deficiency (dMMR) and microsatellite instability (MSI‐H), though this constitutes on average less than 5% of mCRC, and ICI is ineffective in preserved MMR/microsatellite stable disease (pMMR/MSS). Here we review the efficacy of ICI in dMMR/MSI‐H mCRC, poor response to ICI in pMMR/MSS mCRC, role for ICI in locally advanced disease, biomarkers of response, novel immunotherapies, and future directions in targeting resistance mechanisms.