Notably, durable responders had a higher peak CAR T-cell:TB ratio compared with nonresponders (=

Notably, durable responders had a higher peak CAR T-cell:TB ratio compared with nonresponders (= .005) or responders who subsequently relapsed within 1 year after treatment (= .01; Figure 1E). the statistical analysis plan and an extensive panel of biomarkers according to an expanded translational biomarker plan. Univariable and multivariable analyses indicated that rapid CAR T-cell expansion commensurate with pretreatment tumor burden (influenced by product T-cell fitness), the number of CD8 and CCR7+CD45RA+ T cells infused, and host systemic inflammation, were the most significant determining factors for durable response. Key parameters differentially associated with clinical efficacy and toxicities, with both theoretical and practical implications for optimizing CAR T-cell therapy. This trial was registered at as #”type”:”clinical-trial”,”attrs”:”text”:”NCT02348216″,”term_id”:”NCT02348216″NCT02348216. Visual Abstract Open in a separate window Introduction Immunotherapy, especially genetically engineered T-cell therapy, is a revolutionary Foropafant approach in the fight against advanced-stage cancer.1-3 There are now 2 chimeric antigen receptor (CAR) products approved to treat B-cell malignancies,4-9 1 of which is axicabtagene ciloleucel (axi-cel), an anti-CD19 CAR T-cell product approved for treatment of relapsed or refractory large B-cell lymphoma (LBCL) in the United States and the European Union.4,10 Axi-cel demonstrated high objective and durable response rates in the multicenter ZUMA-1 study in adult refractory LBCL,6 consistent with results from an earlier study that used the same CAR construct.11 Axi-cel was associated with toxicities, most notably cytokine release syndrome (CRS) and neurologic events (NEs), which are well described across this class of therapies.12-14 These toxicities are generally reversible and manageable with supportive therapy, corticosteroids, and interleukin-6R (IL-6R) blockade.7,12,13 Despite high clinical efficacy, approximately 60% of patients do not respond to or relapse within 2 years of treatment with axi-cel or other anti-CD19 CAR T-cell therapies.6,8 Mechanisms associated with durable responses remain incompletely elucidated, and previous correlative analyses have largely focused on toxicity and immune programs associated with CAR T-cell therapy.15-26 Data are limited on mechanisms of treatment resistance, including target antigen loss seen in a subset of responding patients. To date, most published correlative data have been generated in leukemia patients, and limited Foropafant information has been obtained from large multicenter trials irrespective of the tumor type. Previous analyses of prespecified clinical covariates, including performance status, age, disease subtype, disease stage, International Prognostic Index score, and cytogenetic status were not clearly predictive of clinical efficacy in ZUMA-1.7,27 Therefore, we initiated this study to analyze biomarker data from ZUMA-1 patients according to an expanded statistical analysis plan for correlates of durable response and parameters differentially associated with efficacy and toxicities. Several strong correlations were revealed. Methods Patient samples Samples from patients in ZUMA-1 were analyzed. The study was approved by the institutional review board at each study site and was conducted in accordance with the Good Clinical Practice guidelines of the International Conference on Harmonization.?Safety and efficacy results were previously reported.7 Durable response referred to patients who were in ongoing response at least 1 year after axi-cel infusion. Relapse referred to those patients who achieved a complete or partial response and subsequently experienced disease progression. Patients who achieved stable disease as best response were considered nonresponders. Quantification of CAR T cells CAR T cells were quantified using TaqMan quantitative polymerase chain reaction (qPCR; Thermo Fisher Scientific) as described28-31 and confirmed by droplet digital PCR (Bio-Rad Laboratories) according to the manufacturers instructions. Unless otherwise noted, results Foropafant Tubb3 shown use the qPCR method (additional details are provided in the supplemental Methods). A mathematical derivation by which CAR cells were normalized to tumor burden (TB) by dividing peak CAR T-cell levels by TB was used as an indirect proxy for effector:target ratio. Analysis of biomarkers and clinical covariates Serum cytokines were analyzed by Simple Plex (Simpleprotein) according to the manufacturers instructions or by using Luminex.