Early ctDNA and survival in dMMR/MSI-H mCRC treated with ICIs: secondary analysis of SAMCO-PRODIGE 54

It is not clear whether change in circulating tumor DNA (ctDNA) levels is predictive over progression-free survival and overall survival in patients receiving immune checkpoint inhibitors (ICIs) for dMMR/MSI-H metastatic colorectal cancer. A prespecified secondary analysis of the randomized SAMCO-PRODIGE 54 trial, at 49 centers in France, assessed ctDNA in 99 patients receiving avelumab or standard chemotherapy for dMMR/MSI-H mCRC. Early ctDNA variation predicted PFS and OS. The authors conclude that early ctDNA monitoring may assist in determining ICI resistance and long-term survival in patients with dMMR/MSI-H mCRC to support more tailored approaches to treatment.