Modified EASIX predicts severe cytokine release syndrome and neurotoxicity after chimeric antigen receptor T cells.

Patients who develop chimeric antigen receptor (CAR) T-cell-related severe cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) exhibit hemodynamic instability and endothelial activation. The EASIX (Endothelial Activation and Stress Index) score (lactate dehydrogenase [LDH; U/L] × creatinine [mg/dL]/platelets [PLTs; 109 cells/L]) is a marker of endothelial damage that correlates with outcomes in allogeneic hematopoietic cell transplantation. Elevated LDH and low PLTs have been associated with severe CRS and ICANS, as has C-reactive protein (CRP), while increased creatinine is seen only in a minority of advanced severe CRS cases. We hypothesized that EASIX and 2 new modified EASIX formulas (simplified EASIX, which excludes creatinine, and modified EASIX [m-EASIX], which replaces creatinine with CRP [mg/dL]), calculated peri-CAR T-cell infusion, would be associated with development of severe (grade ≥ 3) CRS and ICANS. We included 118 adults, 53 with B-acute lymphoblastic leukemia treated with 1928z CAR T cells (NCT01044069) and 65 with diffuse large B-cell lymphoma treated with axicabtagene ciloleucel or tisagenlecleucel. The 3 formulas showed similar predictive power for severe CRS and ICANS. However, low PLTs and high CRP values were the only variables individually correlated with these toxicities. Moreover, only m-EASIX was a significant predictor of disease response. m-EASIX could discriminate patients who subsequently developed severe CRS preceding the onset of severe symptoms (area under the curve [AUC] at lymphodepletion, 80.4%; at day -1, 73.0%; and at day +1, 75.4%). At day +3, it also had high discriminatory ability for severe ICANS (AUC, 73%). We propose m-EASIX as a clinical tool to potentially guide individualized management of patients at higher risk for severe CAR T-cell-related toxicities.

Interventions and outcomes of adult patients with B-ALL progressing after CD19 chimeric antigen receptor T-cell therapy.

CD19-targeted chimeric antigen receptor (CAR) T-cell therapy has become a breakthrough treatment of patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, despite the high initial response rate, the majority of adult patients with B-ALL progress after CD19 CAR T-cell therapy. Data on the natural history, management, and outcome of adult B-ALL progressing after CD19 CAR T cells have not been described in detail. Herein, we report comprehensive data of 38 adult patients with B-ALL who progressed after CD19 CAR T therapy at our institution. The median time to progression after CAR T-cell therapy was 5.5 months. Median survival after post-CAR T progression was 7.5 months. A high disease burden at the time of CAR T-cell infusion was significantly associated with risk of post-CAR T progression. Thirty patients (79%) received salvage treatment of post-CAR T disease progression, and 13 patients (43%) achieved complete remission (CR), but remission duration was short. Notably, 7 (58.3%) of 12 patients achieved CR after blinatumomab and/or inotuzumab administered following post-CAR T failure. Multivariate analysis revealed that a longer remission duration from CAR T cells was associated with superior survival after progression following CAR T-cell therapy. In summary, overall prognosis of adult B-ALL patients progressing after CD19 CAR T cells was poor, although a subset of patients achieved sustained remissions to salvage treatments, including blinatumomab, inotuzumab, and reinfusion of CAR T cells. Novel therapeutic strategies are needed to reduce risk of progression after CAR T-cell therapy and improve outcomes of these patients.

Comparing CAR T-cell toxicity grading systems: application of the ASTCT grading system and implications for management.

Various grading systems are currently used for chimeric antigen receptor (CAR) T-cell-related toxicity, cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS). We compared the recently proposed American Society for Transplantation and Cellular Therapy (ASTCT) grading system to other grading scores in 2 populations of adults: patients (n = 53) with B-cell acute lymphoblastic leukemia (B-ALL) treated with 1928z CAR T-cells (clinicaltrials.gov #NCT01044069), and patients (n = 49) with diffuse large B-cell lymphoma (DLBCL) treated with axicabtagene-ciloleucel (axi-cel) or tisagenlecleucel after US Food and Drug Administration approval. According to ASTCT grading, 82% of patients had CRS, 87% in the B-ALL and 77% in the DLBCL groups (axi-cel: 86%, tisagenlecleucel: 54%), whereas 50% of patients experienced ICANS, 55% in the B-ALL and 45% in the DLBCL groups (axi-cel: 55%, tisagenlecleucel: 15%). All grading systems agreed on CRS and ICANS diagnosis in 99% and 91% of cases, respectively. However, when analyzed grade by grade, only 25% and 54% of patients had the same grade in each system for CRS and ICANS, respectively, as different systems score symptoms differently (upgrading or downgrading their severity), leading to inconsistent final grades. Investigation of possible management implications in DLBCL patients showed that different recommendations on tocilizumab and steroids across current guidelines potentially result in either overtreating or delaying treatment. Moreover, because these guidelines are based on single products and different grading systems, they cannot be universally applied. To avoid discrepancies in assessing and managing toxicities of different products, we propose that unified grading be used across clinical trials and in practice and that paired management guidelines with product-specific indications be developed.