New Approach to Immunotherapy Demonstrates Effectiveness Against Metastatic Colorectal Cancer

A small clinical trial shows a new cellular immunotherapy approach has the potential to be effective in treating metastatic solid tumors. NIH's website has the release.

Researchers from NIH “genetically engineered normal white blood cells, known as lymphocytes, from each patient to produce receptors that recognize and attack their specific cancer cells. These initial findings are from people with metastatic colorectal cancer who had already undergone multiple earlier treatments. The personalized immunotherapy shrank tumors in some patients and was able to keep the tumors from regrowing for up to seven months.”

To date, a cellular therapy effective against most solid cancers has been elusive. This new approach “overcomes two challenges in cellular immunotherapy: how to produce large numbers of T cells that can recognize cancer cells specifically, and how to boost the ability of modified T cells to multiply once they’ve been returned to the patient.”

Each patient had lymphocytes present in their tumors collected, and the researchers “then used sophisticated molecular characterization techniques to identify and isolate receptors on those lymphocytes, called T-cell receptors, that recognized specific changes in each patient’s tumor. After genetically sequencing those receptors, they then used a retrovirus to insert the genes for the receptor into normal lymphocytes collected from each patient’s circulating blood.” The genetically modified lymphocytes were then infused back into the patient.

Three patients had “substantial shrinkage of metastatic tumors in the liver, lung, and lymph nodes that lasted for four to seven months. The median time to disease progression was 4.6 months.”