Sustained Therapeutic Efficacy of Humanized Anti-CD19 Chimeric Antigen Receptor T Cells in Relapsed/Refractory Acute Lymphoblastic Leukemia.

PURPOSE: Immunogenicity derived from the murine scFv, a major molecular compomemt of chimeric antigen receptors (CARs), may limit the persistence of CAR T cells, resulting in tumor relapse of patients in complete remission (CR). In this study, we developed a humanized anti-CD19 scFv CAR-T (hCAR-T) to treat patients with relapsed/refractory acute lymphoblastic leukemia (r/r ALL). PATIENTS AND METHODS: In this one-arm, open-labeled study, we infused the T cells modified with hCAR to patients with r/r ALL. Patients were evaluated with long-term follow-up for response and safety of the treatment. The study was registered at Clinicaltrials.gov (NCT02349698). RESULTS: Ten patients with r/r ALL were recruited for this study. All were response evaluable and all achieved CR; eight patients remained CR, and six were in CR for over 18 months without further treatment. A long-term persistence of hCAR T cells was observed in most of the patients. Among these patients, four of them with high tumor burden and rapidly progressive disease (median, 58%) experienced grade 3-4 cytokine release syndrome (CRS) and neurotoxicity. These severe CRSs were successfully controlled by tocilizumab, glucocorticoid, and plasma exchange. CONCLUSIONS: T cells expressing the humanized anti-CD19 scFv CARs exhibited sustained therapeutic efficacy in the treatment of r/r ALL. Low replase rate was associated with the long-term persistence of CAR T cells.

Treatment of acute lymphoblastic leukaemia with the second generation of CD19 CAR-T containing either CD28 or 4-1BB.

T cells modified with anti-CD19 chimeric antigen receptor (CAR) containing either CD28 or 4-1BB (also termed TNFRSF9, CD137) costimulatory signalling have shown great potential in the treatment of acute lymphoblastic leukaemia (ALL). However, the difference between CD28 and 4-1BB costimulatory signalling in CAR-T treatment has not been well elucidated in clinical trials. In this study, we treated 10 relapsed or refractory ALL patients with the second generation CD19 CAR-T. The first 5 patients were treated with CD28-CAR and the other 5 patients were treated with 4-1BB CAR-T. All the 10 patients were response-evaluable. Three patients achieved complete remission and 1 patient with extramedullary disease achieved partial response after CD28-CAR-T treatment. In the 4-1BB CAR-T treatment group, 3 patients achieved complete remission. Furthermore, FLT-3 ligand (FLT3LG) was highly correlated with response time and may serve as a prognosis factor. No severe adverse events were observed in these 10 treated patients. Our study showed that both CD28 CAR-T and 4-1BB CAR-T both worked for response but they differed in response pattern (peak reaction time, reaction lasting time and reaction degree), adverse events, cytokine secretion and immune-suppressive factor level.

Prognostic factors of lymphoma patients after autologous stem cell transplantation.

UNLABELLED: BacKGROUND: Hematopoietic stem cell transplantation (HSCT) is considered to be a cure for lymphoma. However, factors related to its prognosis remain unclear. MATERIAL AND METHODS: Eighty patients diagnosed with lymphoma and treated with autologous HSCT (Auto HSCT) were recruited. The primary endpoints included overall survival (OS) and progression-free survival (PFS). RESULTS: After a median follow-up of 37.9 months, the 3-year OS was 75%. Univariate analysis showed age (P=0.020), elevated lactate dehydrogenase (LDH) (P=0.031), international prognostic index (IPI) (P=0.015), Eastern Cooperative Oncology Group (ECOG) (P=0.048), bone marrow involvement (P=0.038), and time to neutrophil recovery (P=0.043) were prognostic factors of lymphoma. Multivariate analysis revealed IPI (hazard ratio [HR] 1.60, 95% confidence interval [CI] 1.09-2.34, P=0.016) and time to neutrophil recovery (HR 2.69, 95% CI 1.02-7.07, P=0.045) were independent factors correlated with OS. CONCLUSIONS: IPI and neutrophil recovery are recommendatory predictors for lymphoma patients after Auto HSCT.

[Mechanism of apoptosis of NB4 cells induced by arsenic trioxide and cyclooxygenase-2 expression].

Objective of this study was to investigate the changes of cyclooxygenase-2 expression and mitochondrial membrane potential in apoptotic NB4 cells induced by arsenic trioxide (As(2)O(3)). The morphological changes in apoptosis process of NB4 cells treated by arsenic trioxide were observed under immunofluorescence microscope and DNA electrophoresis method, and the apoptosis rate of NB4 cells and the variations of mitochondrial membrane potential were detected by flow cytometry. Furthermore, the variations of expression level of cyclooxygenase-2 protein were analyzed by using Western blot method. The results indicated that after NB4 cells were treated with 2 µmol/L As(2)O(3) for 48 hours, some variations of NB4 cells were observed, such as pyknosis, chromatin segmentation, even fragmentation. Meanwhile, the typical DNA Ladder phenomenon was observed. The apoptosis rate of NB4 cells treated with 3 µmol/L As(2)O(3) for 48 hours was 33.34%, Furthermore the apoptosis rate of NB4 cells was enhanced along with the increase of concentration of As(2)O(3). After NB4 cells were treated with 0.5, 1, 2, 4 and 8 µmol/L As(2)O(3) for 48 hours, the mitochondrial membrane potential decreased by 12.8%, 21.6%, 66.9%, 83.7% and 83.8% respectively. The Western blot detection results showed that the expression level of cyclooxygenase-2 protein in NB4 cells was lower than that in control cells and decreased along with the rise of As(2)O(3) concentration, then the negative dose-dependent manner was observed between these 2 groups. It is concluded that As(2)O(3) can effectively induce NB4 cell apoptosis, and the dose-dependent manner existed in certain extent of concentrations. The decrease of mitochondrial membrane potential may be related with NB4 cell apoptosis induced by As(2)O(3). Cyclooxygenase-2 participates in the process of NB4 cell apoptosis induced by As(2)O(3).