CD19/CD20 CAR-T Cells(The Parker Institute For Cancer Immunotherapy)

CD19-targeted chimeric antigen receptor-modified T (CAR-T) cells have shown success in clinical studies, with several CD19 CAR-T cell products now having been approved for market use. However, this cell therapy can be associated with side effects such as cytokine release syndrome (CRS). Therefore, pre-clinical test systems are highly desired to permit the evaluation of these unwanted effects before clinical trials begin. In this study, we evaluated cytokine secretion and cell phenotype changes induced by human CD4⁺ and CD8⁺ CD19-targeted CAR-T cells in the cytokine release assay (CRA) module of a pre-clinical human in vitro 3D co-culture platform. The in vitro CRA data showed that CD19-targeted CAR-T cells induced a diverse and concentration-dependent cytokine response led by a T_H1-profile (IFNγ, IL-2) and pro-inflammatory cytokines (IL-6, TNFα, MCP-1, IL-8, MIP-1b). It was also shown that different cellular components in this 3D co-culture system contributed to the CAR-T cell cytokine response. In particular, whole blood-derived cell populations were necessary to drive the production of T cell cytokines, and endothelial cells were required to generate pro-inflammatory cytokines. CD19-targeted CAR-T cells also triggered cell phenotype changes, including the activation of whole blood-derived CD4⁺ and CD8⁺ T-cells and activation/maturation of antigen-presenting cells, during treatment of the in vitro CRA platform. Additionally, the observation of a CD19-targeted CAR-T cell concentration-dependent reduction in the B-cell compartment in this study is aligned with the expected pharmacology and clinical profile of this compound. Overall, this dataset shows the utility of an in vitro CRA model as a pre-clinical platform for evaluating cytokine release potential and analysis of mechanisms of action of CD19-targeted CAR-T cells.

Immune effector cell-associated neurotoxicity syndrome (ICANS) remains a significant cause of morbidity associated with CD19-targeted chimeric antigen receptor (CAR) T-cell therapy. Early prediction of patients who will develop ICANS would be crucial to better guide individualized management of high-risk patients, but specific predictive markers are still missing. Serum neurofilament light chain (NfL) levels are a sensitive indicator of neuroaxonal injury in neurological diseases. Elevated NfL levels at the time of CAR T-cell infusion have been associated with the severity of ICANS, but their utility for earlier identification of patients with subclinical neurological damage has not been evaluated.We studied all consecutive adult patients who received commercial CAR T cells for relapsed/refractory B-cell lymphomas at Saint-Louis Hospital between January 2019 and February 2023. Patients with pre-existing or current neurological disease were excluded. NfL levels were quantified in frozen serum collected at the time of the decision to treat (ie, the day of leukapheresis) and at the time of treatment (ie, the day of infusion).Of the 150 study patients, 28% developed ICANS of any grade, including 15.3% of grade 2–4. Receiving a CAR construct with a CD28 domain (58% of patients) was the strongest predictor of grade 2–4 ICANS. Serum NfL levels were significantly higher in patients with grade 2–4 ICANS than in those with grade 0–1 ICANS, both at the time of leukapheresis and infusion. In multivariate models, NfL above the cut-off value was independently associated with grade 2–4 ICANS at leukapheresis (NfL>75 pg/mL, OR 4.2, 95% CI 1.2 to 14.2, p=0.022) and infusion (NfL>58 pg/mL, OR 4.3, 95% CI 1.3 to 13.7, p=0.015).In conclusion, high NfL levels at the time of the decision to proceed with CAR T-cell manufacturing may represent an early surrogate of underlying loss of neuroaxonal integrity that increases the risk of subsequent neurotoxicity. Incorporating NfL levels into the decision-making process based on each patient’s risk profile could help determine the appropriate CAR product when possible, and guide the prophylactic or therapeutic management of ICANS.