Immune checkpoint inhibitors for patients with colorectal cancer: mismatch repair deficiency and perspectives

Harnessing the immune system to fight tumor cells is becoming a promising and innovative therapeutic strategy for a large spectrum of malignancies. The evaluation of immunotherapy in the context of colorectal cancers (CRCs) has brought to light mismatch repair deficiency as a major predictive biomarker for the efficacy of immune checkpoint blockade. In this review, we summarize the promising results of immune checkpoint inhibitors for patients with metastatic CRCs harboring mismatch repair deficiency, with special emphasis on further clinical development. Given the biological determinants of sensitivity to immune checkpoint blockade, we will also elucidate points that could unlock the potential of immunotherapy for patients with mismatch repair-proficient CRC.