Despite a variety of therapies for advanced metastatic colorectal cancer being available, the outcomes in this malignancy remain suboptimal. Immunotherapy has been slow to impact the management of this patient group. Checkpoint inhibitors, such as nivolumab, have had disappointing results when used broadly. However, for the subset of patients with microsatellite unstable colorectal cancer, the use of checkpoint inhibitors such as nivolumab appears to be transformative, and will provide a new therapeutic option for patient with advanced disease. Areas covered: Nivolumab gained regulatory approval for the treatment of dMMR/MSI-H metastatic colorectal cancer in mid 2017. The current review will summarize the clinical evidence of checkpoint inhibitors in metastatic colorectal cancer, with a focus on nivolumab. Expert commentary: For patients with dMMR/MSI-H mCRC, the use of nivolumab has now been shown to have objective and sustained clinical responses in a pivotal phase II trial. While additional data are limited, the therapeutic role for augmenting an immune response in metastatic colorectal cancer is likely to continue to expand. Further combination trials of nivolumab with immunologic and non-immunologic agents are ongoing.
Keywords: Colorectal cancer; MMR; MSI; anti-PD1; immunotherapy; nivolumab.