Efficacy and safety of third-generation CD19-CAR T cells incorporating CD28 and TLR2 intracellular domains for B-cell malignancies with central nervous system involvement: results of a pivotal trial
Bailin He, Ren Lin, Na Xu, Le Qin, Zhixiang Wang, Qiang Wang, Xiaofang Li, Xiaolei Wei, Yongqiang Wei, Zhaoyang Tang, Zhiping Fan, Fen Huang, Xiaoli Liu, Jing Sun, Li Xuan, Peng Li, Hongsheng Zhou, Qifa Liu
Abstract
BACKGROUND: Third‑generation CAR-T cells demonstrated promising efficacy and remarkably low toxicity in refractory or relapsed (R/R) B-cell malignancies. However, data on the patients with central nervous system (CNS) involvement are limited due to concerns regarding treatment-related neurotoxicity. This study aimed to evaluate the safety and efficacy of a novel third-generation anti-CD19 CAR T cells in patients with CNS involvement of B-cell malignancies. METHODS: A total of 21 patients with R/R B-cell malignancies with CNS involvement, including 11 with B-cell acute lymphoblastic leukemia (B-ALL) and 10 with B-cell non-Hodgkin lymphoma (B-NHL) were enrolled. Patients derived lymphocytes were collected through apheresis and lentivirally transduced with the third-generation CAR incorporating both CD28 co-stimulation and TLR2-derived stimulatory domains (1928zT2). Patients received a single-dose 1928zT2 CAR-T cell infusion following lymphodepleting regimen. Safety, efficacy and cellular pharmacokinetics were investigated. RESULTS: Of the 21 patients with CNS involvement, the overall response rate (ORR) was 71% (15/21), with 73% (8/11) in B-ALL and 70% (7/10) in B-NHL. At a median follow-up of 20.4 months, median duration of response (DOR) was 11.1 months (95% CI, 2.9-24.4). 12-months progression-free survival (PFS) and overall survival (OS) estimates were 41.5% and 61.2%, respectively. Cytokine release syndrome (CRS) of any grade occurred in 20 patients (95%; grade ≥ 3 in 3 patients). Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 9 patients (42.8%; grade ≥ 3 in 6 patients). All CRS and ICANS events were manageable. The outcomes and adverse events are comparable between B-ALL and B-NHL patients. Notably, 1928zT2 CAR-T cells demonstrated blood-brain barrier penetrance, with subsequent detection in patient cerebrospinal fluid (CSF) correlating significantly with improved clinical outcomes. CONCLUSIONS: Third-generation 1928zT2 CAR-T cells are associated with high response rates, manageable safety and durable remissions in R/R B-cell malignancies with CNS involvement. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04605666. Registered 1 May 2020.