FDA approvals for mismatch repair deficiency in metastatic colorectal cancer and hepatocellular carcinoma: a next-generation oncology treatment based on biomarker expression

Colorectal, gastric and hepatocellular cancers have been traditionally considered to be poorly immunogenic; however, increasing evidence now suggests that these tumors are recognized by the immune system. Immune checkpoint blockade is showing promising clinical activity in multiple tumors including colorectal and non-colorectal. In fact, one of the most significant achievements witnessed in the field of immunotherapy has been the success of immune checkpoint inhibitors (CPIs) in microsatellite instability-high colorectal and non-colorectal tumors. For this reason, the US FDA has granted accelerated approval to Pembrolizumab and Nivolumab as monotherapies and Nivolumab plus Ipilimumab as combined therapy. These new findings open the door to a next-generation oncology treatment based on biomarker expression.