The Endothelial Activation and Stress Index (EASIX) score, defined as [(creatinine × lactate dehydrogenase [LDH])/platelets], is a marker of endothelial activation that has been validated in the allogeneic hematopoietic stem cell transplant setting. Endothelial activation is one of the mechanisms driving immune-mediated toxicities in patients treated with chimeric antigen receptor-T (CAR-T)-cell therapy. This study’s objective was to evaluate the association between EASIX and other laboratory parameters collected before lymphodepletion and the subsequent onset of cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) those patients. Toxicity data were collected prospectively on 171 patients treated with axicabtagene ciloleucel (axi-cel) for large B-cell lymphoma (LBCL). CRS grades 2 to 4 were diagnosed in 81 (47%) patients and ICANS grades 2 to 4 in 84 (49%). EASIX combined with ferritin (EASIX-F) identified 3 risk groups with CRS grades 2 to 4 cumulative incidence of 74% (hazards ratio [HR], 4.8; 95% confidence interval [CI], 2.1-11; P < .001), 49% (HR, 2.3; 95% CI, 1.02-5; P = .04), and 23% (reference), respectively. EASIX combined with CRP and ferritin (EASIX-FC) identified 3 risk groups with an ICANS grade 2 to 4 cumulative incidence of 74% (HR, 3.6; 95% CI, 1.9-6.9; P < .001), 51% (HR, 2.1; 95% CI, 1.1-3.9; P = .025), and 29% (reference). Our results indicate that common laboratory parameters before lymphodepletion correlate with CAR-T–related toxicities and can help support clinical decisions, such as preemptive toxicity management, hospitalization length, and proper setting for CAR-T administration.

To explore the role of clonal hematopoiesis (CH) in chimeric antigen receptor (CAR) T-cell therapy outcomes, we performed targeted deep sequencing on buffy coats collected during the 21 days before lymphodepleting chemotherapy from 114 large B-cell lymphoma patients treated with anti-CD19 CAR T cells. We detected CH in 42 (36.8%) pretreatment samples, most frequently in PPM1D (19/114) and TP53 (13/114) genes. Grade ≥3 immune effector cell-associated neurotoxicity syndrome (ICANS) incidence was higher in CH-positive patients than CH-negative patients (45.2% vs. 25.0%, P = 0.038). Higher toxicities with CH were primarily associated with DNMT3A, TET2, and ASXL1 genes (DTA mutations). Grade ≥3 ICANS (58.9% vs. 25%, P = 0.02) and ≥3 cytokine release syndrome (17.7% vs. 4.2%, P = 0.08) incidences were higher in DTA-positive than in CH-negative patients. The estimated 24-month cumulative incidence of therapy-related myeloid neoplasms after CAR T-cell therapy was higher in CH-positive than CH-negative patients [19% (95% CI, 5.5–38.7) vs. 4.2% (95% CI, 0.3–18.4), P = 0.028]. Significance: Our study reveals that CH mutations, especially those associated with inflammation (DNMT3A, TET2, and ASXL1), are associated with severe-grade neurotoxicities in lymphoma patients receiving anti-CD19 CAR T-cell therapy. Further studies to investigate the mechanisms and interventions to improve toxicities in the context of CH are warranted. See related content by Uslu and June, p. 382. This article is highlighted in the In This Issue feature, p. 369

Use of adoptive T-cell therapy modified with chimeric antigen receptor (CAR-T) has revolutionized treatment of patients with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia(B-ALL). CAR-modified T-cells directed against CD19 antigen have produced response rates as high as 90% in clinical trials for r/r B-ALL. Despite high rates of complete remissions, the durability of responses has been poor with frequent relapses, especially in adult B-ALL population. Systemic toxicities from CAR T-cell therapy and standardization of toxicities grading and management is another major hurdle in the developing CAR-T field. In this review, we discuss the latest evidence of CAR-T therapy in B-ALL, potential mechanisms of relapse and barriers to CAR-T cell therapy in B-ALL. We also debate on the role of allogeneic hematopoietic stem cell transplant (allo-HCT) post CAR-T therapy.

Background: Antiretroviral therapy is frequently associated with adverse metabolic effects and lipodystrophy, but the role of HIV protease inhibitors and the mechanisms involved are poorly understood. The HIV protease inhibitor nelfinavir (NFV) impairs insulin signal propagation by inducing similar signalling defects to those induced by exposure to oxidative stress. Aim: We set out to determine if oxidative stress is involved in NFV-induced insulin resistance in 3T3-L1 adipocytes, and whether antioxidant agents with unique modes of action can prevent this effect. Results: Cells exposed to NFV exhibited the following markers of increased oxidative stress: a decrease in both total and low molecular weight reduced thiols, a 20-fold increase in haem oxygenase 1 (HO-1) mRNA, an increase in intracellular reactive oxygen species production (determined by 2′,7′-dichlorofluorescein fluorescence), and increased markers of apoptosis. Enhancing cellular thiols with N-acetylcystein prevented the NFV-induced drop in reduced thiols and partially protected against the induction in HO-1, but failed to prevent insulin resistance or cleavage of poly ADP ribose polymerase (PARP), a process indicative of activation of pro-apoptotic caspases. Conversely, the superoxide dismutase-mimetic antioxidant MnTBAP had no effect on cellular thiols in response to NFV, but protected against HO-1 induction and against the impairment in insulin-stimulated Akt/protein kinase B activation and PARP cleavage. Conclusions: Induction of oxidative stress plays a role in adipocyte insulin resistance and apoptosis induced by NFV through a radical-dependent but thiol-independent mechanism(s). The results may suggest a new mechanism for the adverse effects of NFV on fat cells, and offer potential new intervention approaches.

Engineering immune cells to target cancer is a rapidly advancing technology. The first commercial products, chimeric-antigen receptor (CAR) T cells, are now approved for hematologic malignancies. However, solid tumors pose a greater challenge for cellular therapy, in part because suitable cancer-specific antigens are more difficult to identify and surrounding healthy tissues are harder to avoid. In addition, impaired trafficking of immune cells to solid tumors, the harsh immune-inhibitory microenvironment, and variable antigen density and presentation help tumors evade immune cells targeting cancer-specific antigens. To overcome these obstacles, T cells are being engineered to express defined T-cell receptors (TCR). Given that TCRs target intracellular peptides expressed on tumor MHC molecules, this provides an expanded pool of potential targetable tumor-specific antigens relative to the cell-surface antigens that are targeted by CAR T cells. The affinity of TCR T cells can be tuned to allow for better tumor recognition, even with varying levels of antigen presentation on the tumor and surrounding healthy tissue. Further enhancements to TCR T cells include improved platforms that enable more robust cell expansion and persistence; coadministration of small molecules that enhance tumor recognition and immune activation; and coexpression of cytokine-producing moieties, activating coreceptors, or mediators that relieve checkpoint blockade. Early-phase clinical trials pose logistical challenges involving production, large-scale manufacturing, and more. The challenges and obstacles to successful TCR T-cell therapy, and ways to overcome these and improve anticancer activity and efficacy, are discussed herein.