Fig. 4

Evaluation of patient’s CSF and serum following CD5-IL15/IL15sushi CAR T cells. a CD5-IL15/IL15sushi CAR T cells were able to rapidly reduce the WBC count of the CSF to normal levels (< 5 × 10⁶ cells/L) 2 weeks post-infusion. The reduction of WBCs was associated with marked improvements in the patient’s (b) CSF pressure and (c) protein levels within the CNS, leading to resolution of the patient’s severe headache. d CD5 + CD3 + CD8 + T cells were measured to determine CD5-IL15/IL15sushi CAR T cell’s effect on the patient’s normal T population. As CD5-IL15/IL15sushi CAR T cells are CD5-, the CAR T cell expansion would not affect this measurement. Despite being CD5+, there was remarkably limited T cell aplasia with the T cells returning to normal levels 9 days after CAR injection. Measurement of (e) ferritin and (f) Hs-CRP, markers of inflammation, demonstrated a mild Grade I CRS toxicity following CAR therapy. Levels returned to normal within 1 month. g Measurement of cytokine levels showed remarkably stable cytokine levels following CD5-IL15/IL15sushi CAR T cell therapy, demonstrating a limited and localized response. Importantly, despite secretion of IL15/IL15sushi complex from the CAR T cells, IL-15 levels remained low post-therapy