Post-infusion CAR TReg cells identify patients resistant to CD19-CAR therapy

In an effort to determine biomarkers for increased risk of disease progression or severe neurotoxicity after CAR T-cell therapy, researchers performed single-cell proteomic profiling of circulating CAR T cells for 32 patients who were treated with CD19-CAR T-cell therapy. Lower rates of severe neurotoxicity and a higher likelihood of disease progression were found to be associated with a higher frequency of CD4-positive CAR T cells expressing Helios on Day 7 post-infusion.