In a first-in-human Phase 1 trial, researchers from the University of Minnesota used CRISPR/Cas9 gene-editing technology to modify tumor-infiltrating lymphocytes (TILs) in patients with advanced gastrointestinal (GI) cancers, particularly metastatic colorectal cancer. The team knocked out a gene called CISH, which acts as an internal checkpoint limiting T cell effectiveness. Disabling this gene enhanced the immune cells’ ability to recognize and attack tumors.
Twelve late-stage patients were treated with over 10 billion gene-edited T cells, with no major safety concerns. Several showed disease stabilization, and notably, one patient achieved a complete response, with cancer disappearing and remaining undetectable for over two years.