EASIX and m-EASIX Predict CRS and ICANS in Pediatric and AYA Patients post CD19-CAR T cell Therapy

• EASIX and m-EASIX scores predict development of CRS and ICANS in pediatric and AYA patients post CD19-CAR T cell therapy.

• EASIX and m-EASIX scores strongly predict severe CRS and ICANS, with severe CRS performance up to 90.6% AUC.

Cytokine release syndrome (CRS) and immune-effector cell associated neurotoxicity syndrome (ICANS) are complications of CD19-directed chimeric antigen receptor (CD19-CAR) T-cell therapy. The Endothelial Activation and Stress Index (EASIX) and modified EASIX (m-EASIX) scores have been retrospectively proven to be predictive of CRS and ICANS in adult CAR T cell recipients. However, these scores have not been evaluated in pediatric cohorts. We retrospectively report on 76 pediatric, adolescent and young adult (AYA) patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL) treated with CD19-CAR T cells at St. Jude Children's Research Hospital or John's Hopkins Hospital. Data included patient-, disease-, and treatment characteristics. EASIX and m-EASIX scores were calculated at days -5 pre, 0 and +3 post CAR T cell infusion. CRS and ICANS occurred in 47 and 17 patients, respectively. At all evaluated time points, compared to those with no/mild CRS/ICANS, median EASIX scores were higher for patients who developed severe CRS and any-grade ICANS, and median m-EASIX scores were higher in patients who developed severe CRS and severe ICANS. Receiver Operating Characteristic (ROC) curve analysis showed that both scores were strong predictors of CRS, especially severe CRS, at all time points. Any grade and severe ICANS were best predicted by both scores at day +3. m-EASIX uniformly outperformed EASIX, except for predicting any grade ICANS. Our results validate the potential utility for EASIX and m-EASIX scores for predicting CAR T-cell related complications for pediatric and AYA patients.