Fatal neurotoxicity after chimeric antigen receptor T-cell therapy: An unexpected case of fludarabine-associated progressive leukoencephalopathy

Severe persistent neurotoxicity associated with CAR T therapy in children

CD19-directed chimeric antigen receptor (CAR) T-cell therapy is an important therapy for relapsed or refractory acute lymphoblastic leukaemia, but its use carries the risk of immune effector cell-associated neurotoxicity syndrome (ICANS). In children, severe ICANS is almost universally reported in association with cytokine release syndrome and is reversible. We describe two cases of severe, intractable neurotoxicity following CAR T-cell therapy in children with pre-existing central nervous system (CNS) vulnerabilities. The cases were atypical in their delayed onset and independence from cytokine release syndrome and did not respond to standard therapies.

A Pharmacovigilance Study on the Safety of Axicabtagene Ciloleucel Based on Spontaneous Reports from the EudraVigilance Database

During pre-approval clinical trials, the safety of axi-cel, a second-generation CAR-T-cell therapy directed against CD19, which dramatically improved the prognosis of intractable B-cell lymphomas, has been investigated only in about 400 patients. Therefore, additional information on this issue is urgently needed. In the present paper, we evaluated the 2905 ICSRs with axi-cel as the suspected drug that had been uploaded in the EudraVigilance database from 1 January 2018 to 31 December 2022. About 80% of the reported adverse events were serious, and about 20% of them did not fully resolve or caused death. The adverse events most-frequently reported were Nervous system disorders (25.6%) and, among them, immune-effector-cell-associated neurotoxicity syndrome, followed by Immune system disorders (23.1%), General disorders and administration site conditions (12.0%), Blood and lymphatic system disorders (7.2%), and Infections and infestations (5.8%). Disproportionality analysis showed that the frequency of reported adverse events related to the nervous system was higher with axi-cel than with the other approved CAR-T-cells, except brexu-cel. In conclusion, real-world pharmacovigilance data showed that nervous system and immune system disorders are the adverse events most reported in axi-cel-related ICSRs and suggest that axi-cel could be more neurotoxic than other CAR-T-cells.

Multifocal demyelinating leukoencephalopathy and oligodendroglial lineage cell loss with immune effector cell-associated neurotoxicity syndrome (ICANS) following CD19 CAR T-cell therapy for mantle cell lymphoma

Immune effector cell-associated neurotoxicity syndrome (ICANS) is a prevalent condition seen after treatment with chimeric antigen receptor T-cell (CAR T) therapy and other cancer cell therapies. The underlying pathophysiology and neuropathology of the clinical syndrome are incompletely understood due to the limited availability of brain tissue evaluation from patient cases, and a lack of high-fidelity preclinical animal models for translational research. Here, we present the cellular and tissue neuropathologic analysis of a patient who experienced grade 4 ICANS after treatment with anti-CD19 CAR T therapy for mantle cell lymphoma. Our pathologic evaluation reveals a pattern of multifocal demyelinating leukoencephalopathy associated with a clinical course of severe ICANS. A focused analysis of glial subtypes further suggests region-specific oligodendrocyte lineage cell loss as a potential cellular and pathophysiologic correlate in severe ICANS. We propose a framework for the continuum of neuropathologic changes thus far reported across ICANS cases. Future elucidation of the mechanistic processes underlying ICANS will be critical in minimizing neurotoxicity following CAR T-cell and related immunotherapy treatments across oncologic and autoimmune diseases.

Successful administration of chimeric antigen receptor (CAR) T-cell therapy in patients requiring hemodialysis

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of relapsed/refractory B-cell malignancies. However, there is no data on the safety and efficacy of CAR T-cell therapy in patients with end stage renal disease (ESRD) requiring dialysis. In this report, we present two patients with DLBCL and ESRD who were successfully treated with different CAR T-cell products. Patient #1 is a 66 year-old woman with a history of HIV who was treated to complete response with axicabtagene ciloleucel with treatment complicated by grade 1 cytokine release syndrome (CRS) and grade 2 immune effector cell-associated neurolotoxicity syndrome (ICANS). Patient #2 is 52 year old woman whose ESRD was caused by ifosphamide toxicity and was treated to complete response with lisocabtagene maraleucel and did not experience either CRS or ICANS. Both patients received lymphodepletion chemotherapy with fludarabine and cyclophosphamide, which was dose-adjusted for ESRD with scheduled dialysis 12 h after each dose of lymphodepletion chemotherapy. Patients with DLBCL and ESRD can be safely administered both lymphodepletion chemotherapy and CAR T-cell therapy. Additionally, the fact that both patients achieved complete response to therapy suggests that CAR T-cell therapy should be strongly considered in patients with ESRD. Long-term follow up is needed to determine if therapy in this setting is of curative intent.