Cancer patients who don’t respond to immunotherapy lack crucial immune cells
Source: Washington University School of Medicine in St. Louis, February 2023
Immunotherapy has transformed cancer care. In advanced melanoma, for example, the most fatal form of skin cancer, the five-year survival rate has risen from less than 10% to more than 50% since immunotherapy was introduced in 2011. Still, only about half of melanoma patients respond to immunotherapy, and those who do not respond face a difficult future.
Researchers at Washington University School of Medicine in St. Louis have discovered that the difference between people who do and do not respond to immunotherapy may have to do with an immune cell known as CD5+ dendritic cells because they bear the protein CD5 on their outer surfaces. Their research showed that people with a variety of kinds of cancers, including melanoma, lived longer if they had more CD5+ dendritic cells in their tumors, and that mice that lacked CD5 on their dendritic cells were unable to respond well to immunotherapy.
The findings, published Feb. 17 in the journal Science, suggest that a supplementary therapy designed to increase the number or activity of CD5+ dendritic cells potentially could extend the lifesaving benefits of immunotherapy to more cancer patients.