Tumor Microenvironment Composition and Severe Cytokine Release Syndrome (CRS) Influence Toxicity in Patients with Large B-Cell Lymphoma Treated with Axicabtagene Ciloleucel.

PURPOSE: One of the challenges of adoptive T-cell therapy is the development of immune-mediated toxicities including cytokine release syndrome (CRS) and neurotoxicity (NT). We aimed to identify factors that place patients at high risk of severe toxicity or treatment-related death in a cohort of 75 patients with large B-cell lymphoma treated with a standard of care CD19 targeted CAR T-cell product (axicabtagene ciloleucel). EXPERIMENTAL DESIGN: Serum cytokine and catecholamine levels were measured prior to lymphodepleting chemotherapy, on the day of CAR T infusion and daily thereafter while patients remained hospitalized. Tumor biopsies were taken within 1 month prior to CAR T infusion for evaluation of gene expression. RESULTS: We identified an association between pretreatment levels of IL6 and life-threatening CRS and NT. Because the risk of toxicity was related to pretreatment factors, we hypothesized that the tumor microenvironment (TME) may influence CAR T-cell toxicity. In pretreatment patient tumor biopsies, gene expression of myeloid markers was associated with higher toxicity. CONCLUSIONS: These results suggest that a proinflammatory state and an unfavorable TME preemptively put patients at risk for toxicity after CAR T-cell therapy. Tailoring toxicity management strategies to patient risk may reduce morbidity and mortality.

Adding chimeric antigen receptor-induced killer cells to the medical oncology shelf.

With the approval of CD19-targeted chimeric antigen receptor (CAR) T cells for the treatment of B cell malignancies, clinicians have gained valuable insights into the power and challenges of cellular therapies. In this issue of the JCI, Maluski et al. showed that a CAR containing a CD28 costimulatory domain drives progeny differentiation to resemble that of NK cells, which have the potential for an off-the-shelf cell therapy. These CAR-induced killer (CARiK) cells displayed potent antitumor function and killed across the MHC barrier in vivo. After performing in vitro and in vivo mouse studies, the authors also successfully differentiated human umbilical cord blood-derived progenitor cells into CARiK cells. These unique cells may address some of the current challenges associated with first-generation CARs, such as prolonged production that requires patients to wait weeks for infusion. We believe this innovative progenitor gene-engineered lymphoid system has the potential for clinical translation.