Expanding Impact of CAR T Cell Therapy: An Immunotherapy Strategy That May Work Against Virtually All Blood Cancers

A broad new strategy could hold hope for treating virtually all blood cancers with CAR T cell therapy, which is currently approved for five subtypes of blood cancer. Scientists in the Perelman School of Medicine at the University of Pennsylvania have demonstrated the potential efficacy of the new approach in preclinical tests. In the study, published August 31, 2023 in Science Translational Medicine, the researchers used engineered CAR T cells to target CD45—a surface marker found on nearly all blood cells, including nearly all blood cancer cells. Because CD45 is found on healthy blood cells too, the research team used CRISPR base-editing to develop a method called “epitope editing” to overcome the challenges of an anti-CD45 strategy, which would otherwise result in low blood counts, with potentially life-threating side effects. The early results represent a proof-of-concept for epitope editing, which involves changing a small piece of the target CD45 molecule just enough so that the CAR T cells don’t recognize it, but it can still function normally within the blood immune system. The article is titled "Epitope Base Editing CD45 in Hematopoietic Cells Enables Universal Blood Cancer Immune Therapy."