Avelumab Combined With Cetuximab and Irinotecan for Treatment Refractory Metastatic Colorectal Microsatellite Stable Cancer

Cancer immunotherapy with immunostimulatory antibodies targeting the CTLA-4 or PD-1/PD-L1 pathways has demonstrated its efficacy in variable proportions of cancer. For metastatic colorectal cancer (mCRC) it appeared that only the small subgroup of patients with MSI-H tumors (microsatellite instability-high phenotype) had a clinically meaningful response to the anti-PD-1- L1 antibodies. In the majority group of non-MSI-H CRC (90-95% of patients), current research expect that additional means would be able to render the tumor "immunogenic" (like MSI-H CRC) and increase the intratumoral immune infiltrate which is the prerequisite to observe a benefit from PD1-PD-L1 inhibitors. Combinations of immune checkpoint inhibitors and procedures that increase intratumoral immune responses, such as targeted therapy, are actively explored.