Objective: Murine CD19 chimeric antigen receptor T-cell (CAR-T) products have been approved for the treatment of refractory/relapsed (R/R) B-cell acute lymphocytic leukemia (B-ALL) ; moreover,
humanized products are also undergoing clinical trials. This study aimed to explore the differences in safety and short- and long-term follow-up efficacy between
humanized and murine CD19 CAR-T-cells for treating relapsed and refractory B-ALL. Methods: Clinical data of 80 patients with R/R B-ALL treated with CD19-targeted CAR-T-cells at the Union Hospital of Tongji Medical College of Huazhong University of Science and Technology between May 2016 and March 2023 were analyzed, which included 31 patients with murine CAR-T and 49 with humanized products. Results: The proportion of patients with cytokine-release syndrome (CRS) in the murine and
humanized groups was 63.1% and 65.3%, respectively. Moreover, a higher proportion of patients suffered from severe CRS in the murine group than in the humanized CAR-T group (19.4% vs 8.2%, P=0.174). Furthermore, one patient per group died of grade 5 CRS. The incidence of grade 1-2 immune effector cell-associated neurotoxicity syndrome (ICANS) was 12.9% and 6.1%, respectively; severe ICANS were not observed. Among patients receiving murine CAR-T-cells, an overall response (OR) was observed in 74.2%. Conversely, the OR rate of patients receiving
humanized CAR-T-cells was 87.8%. During the median follow-up time of 10.5 months, the median recurrence-free survival (RFS) of patients with murine CAR-T-cells was 12 months, which was as long as that of patients with humanized CAR-T-cells. The median overall survival (OS) were not reached in both groups. Of the 45 patients with a bone marrow burden over 20% at baseline, humanized CAR-T therapy was associated with a significantly improved RFS (43.25% vs 33.33%, P=0.027). Bridging transplantation was an independent factor in prolonging OS (χ(2)=8.017, P=0.005) and PFS (χ(2)=6.584, P=0.010). Common risk factors, such as age, high proportion of bone marrow blasts, and BCR-ABL fusion gene expression, had no significant effect on patients\' long-term follow-up outcomes. Three patients reached complete remission after reinfusion of
humanized CAR-T-cells. However, one patient relapsed one month after his second infusion of murine CAR-T-cells. Conclusions: The results indicate that humanized CAR-T therapy showed durable efficacy in patients with a higher tumor burden in the bone marrow without any influence on safety. Moreover, it could overcome immunogenicity-induced CAR-T resistance, providing treatment options for patients who were not treated successfully with CAR-T therapies.
目的: 探索人源化和鼠源CD19嵌合抗原受体T细胞(CAR-T细胞)治疗复发/难治急性B淋巴细胞白血病(B-ALL)安全性、短期及长期随访的疗效差异。 方法:分析2016年5月至2023年3月于华中科技大学同济医学院附属协和医院接受CD19 CAR-T细胞治疗的80例R/R B-ALL患者的有效性和安全性,其中接受鼠源CAR-T治疗31例,人源化CAR-T治疗49例。 结果: 鼠源和人源化组患者发生细胞因子释放综合征(CRS)的比例分别为61.3%和65.3%,其中接受鼠源CAR-T的患者发生重症CRS的比例高于人源化CAR-T(19.4%对8.2%,P=0.174),两组中分别有1例患者死于严重CRS。1~2级免疫效应细胞相关神经毒性综合征(ICANS)的发生率为12.9%和6.1%,无患者发生高级别ICANS。鼠源组和人源化组中白血病患者的总体反应率分别为74.2%和87.8%。在中位时间为10.5个月的随访期中,两组患者中位无复发生存(RFS)期均为12个月,中位总生存(OS)期均未达到。在45例基线骨髓白血病细胞负荷>20%的患者中,接受人源化CAR-T治疗的患者1年PFS率显著高于鼠源组(43.25%对33.33%,P=0.027)。桥接移植是改善B-ALL患者OS(χ(2)=8.017,P=0.005)及RFS(χ(2)=6.584,P=0.010)的独立影响因素。常见高危因素(年龄、骨髓高肿瘤负荷、BCR-ABL融合基因)对长期随访结果无显著影响。3例人源化组患者多次回输后仍达完全缓解,1例鼠源组患者复发后二次回输鼠源CAR-T细胞RFS期仅1个月。 结论: 与接受鼠源CAR-T疗法治疗的患者相比,人源化CAR-T在不影响安全性的前提下,在高肿瘤负荷患者中显示出更持久的疗效,并有效克服免疫原性导致的CAR-T耐药,为多次复发患者提供治疗选择。.