[Chimeric antigen receptors T cells for treatment of 48 relapsed or refractory acute lymphoblastic leukemia children: long term follow-up outcomes]

Consolidative Hematopoietic Stem Cell Transplantation After CD19 CAR-T Cell Therapy for Acute Lymphoblastic Leukemia: A Systematic Review and Meta-analysis

BACKGROUND

This study aimed to systematically evaluate and compare the efficacy and safety of consolidative hematopoietic stem cell transplantation (HSCT) after CD19 chimeric antigen receptor T (CAR-T) therapy with non-HSCT in the treatment of acute lymphoblastic leukemia (ALL).

METHODS

The PubMed, Embase, Cochrane Library and Web of Science databases were searched for clinical trials. Pooled hazard ratios (HRs) for overall survival (OS), relapse rate, and leukemia-free survival (LFS) as well as overall incidence rates for transplant-related mortality (TRM), acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD), and infections were calculated using Stata software.

RESULTS

We screened 3,441 studies and identified 19 eligible studies with 690 patients. Among the patients who achieved complete remission (CR) after CD19 CAR-T therapy, consolidative HSCT was beneficial for OS (HR = 0.34, 95% CI, 0.170.68, P = 0.003), the relapse rate (HR = 0.16, 95% CI, 0.100.25, P < 0.001), and LFS (HR = 0.15, 95% CI, 0.080.28, P < 0.001). For patients who achieved MRD-negative (neg) CR after CD19 CAR-T therapy, consolidative HSCT was beneficial for OS (0.57, 95% CI, 0.330.99, P = 0.045), the relapse rate (0.14, 95% CI, 0.060.31, P < 0.001), and LFS (0.21, 95% CI, 0.120.35, P < 0.001). Regarding safety, we calculated pooled incidence rates for TRM (8%, 95% CI, 0.020.15), aGVHD (44%, 95% CI, 0.230.67), cGVHD (36%, 95% CI, 0.170.56), and infections (39%, 95% CI, 0.030.83).

CONCLUSIONS

Compared with non-HSCT treatment, consolidative HSCT after CD19 CAR-T therapy for R/R B-ALL patients can prolong OS and LFS and reduce the risk of relapse. The incidence rates for adverse events are acceptable. More high-quality randomized controlled trials are required to avoid bias and further determine the efficacy of HSCT.

Anti-CD19 CAR-T cell therapy bridge to HSCT decreases the relapse rate and improves the long-term survival of R/R B-ALL patients: a systematic review and meta-analysis

Chimeric antigen receptor (CAR) T cell therapy improves the remission rate of refractory/relapsed B-acute lymphoblastic leukemia (R/R B-ALL) patients, but the relapse rate remains high. Recent studies suggest patients who underwent post-chimeric antigen receptor T cell therapy hematopoietic stem cell transplantation (post- HSCT) would achieve durable remission and better survival, but this remains controversial. To this end, we conducted a meta-analysis to assess the role of post-HSCT in R/R B-ALL. The Cochrane Library, Embase, and PubMed were used to identify relevant studies; the latest search update was on July 05, 2020. We used the Cochran Q test and I-squared statistics to test for heterogeneity among the studies analyzed. The fixed model and random model were used to combine results when appropriate. We performed all statistical analyses with Stata 12, and P < 0.05 was considered statistically significant. We included 18 studies with 758 patients in the meta-analysis. Our results indicated that post-HSCT was associated with lower relapse rate (RR: 0.40, 95% CI: 0.32-0.50, P = 0.000), better overall survival (HR: 0.37, 95% CI: 0.19-0.71, P = 0.003), better leukemia-free survival (HR: 0.20, 95% CI: 0.10-0.40, P = 0.000). However, post-HSCT did not influence OS in Caucasians, and CAR-T cells with CD28 co-stimulation factor bridged to HSCT did not influence OS. Post-HSCT decreased the relapse rate and improved the long-term survival of R/R B-ALL patients. R/R B-ALL patients would benefit from post-HSCT after CAR-T cell therapy.

[CAR T-cell bridging to allo-HSCT for relapsed/refractory B-cell acute lymphoblastic leukemia: the follow-up outcomes]

Objective: This study aims to investigate the efficacy and safety of chimeric antigen receptor (CAR) T-cell bridging allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of recurrent and refractory acute B-lymphocytic leukemia (R/R B-ALL) . Methods: A total of 50 R/R B-ALL patients who underwent CAR T-scell therapy to bridge allo-HSCT in the First Affiliated Hospital of Soochow University from January 2017 to May 2019 were retrospectively analyzed. The overall survival (OS) rate, event-free survival (EFS) rate, cumulative recurrence rate (CIR) , and transplant-related mortality (TRM) of patients with different bone marrow minimal residual disease (MRD) levels were analyzed before and after CAR T-cell infusion and before allo-HSCT. Results: The response rate of CAR T-cell therapy and the incidence rate of severe cytokine release syndrome were 92% and 28% , respectively. During 55 infusions, no treatment-related deaths occurred in any of the patients. The median time of CAR T-cell infusion to allo-HSCT was 54 (26-232) days, the median follow-up time after CAR T-cell infusion was 637 (117-1097) days, and the 1-year OS and EFS rates were (80.0±5.7) % and (60.0±6.9) % . The 1-year CIR and TRM after allo-HSCT were (28.0±0.4) % and (8.0±0.2) % . After CAR T-cell infusion and before allo-HSCT, patients with bone marrow MRD<0.01% had a significantly longer EFS [ (70.0±7.2) % vs (20.0±12.6) % , P<0.001; (66.7±7.5) % vs (36.4±14.5) % , P=0.008]and lower CIR [ (25.0±0.5) % vs (70.0±2.6) % , P<0.001; (23.08±0.47) % vs (45.45±2.60) % , P=0.038]. Conclusion: CAR T-cell therapy bridging allo-HSCT is safe and effective for recurrent and refractory B-ALL.

Cluster of differentiation 19 chimeric antigen receptor T-cell therapy in pediatric acute lymphoblastic leukemia

Chimeric antigen receptor (CAR) T cells have an unprecedented positive curative effect for hematological malignances. Most notably, cluster of differentiation 19 (CD19) CAR T-cell therapy for pediatric acute lymphoblastic leukemia is associated with a high complete remission rate and has aroused considerable attention in the medical field. However, it also causes a series of adverse reactions and increases the risk of recurrence. The present review examines the results of CD19 CAR T-cell therapy and lists its adverse effects. In addition, some of the mechanisms of recurrence are characterized and applicable strategies to address this challenging problem are proposed.

[Safety and efficacy of patients with refractory B-lymphoblastic leukemia treated with anti-CD19 CAR-T cell bridging to allogeneic hematopoietic stem cell transplantation]

目的

探讨抗CD19 CAR-T细胞治疗达深度缓解后序贯异基因造血干细胞移植（allo-HSCT）治疗难治B淋巴细胞白血病的疗效及不良反应。

方法

回顾性分析2017年11月至2019年3月河南省肿瘤医院收治的10例抗CD19 CAR-T细胞治疗达深度缓解后序贯allo-HSCT难治B淋巴细胞白血病患者的临床资料。

结果

①10例患者中，男5例，女5例，中位年龄23.5（10～31）岁，其中难治急性B淋巴细胞白血病（B-ALL）9例，慢性淋巴细胞白血病（CLL）1例。10例患者抗CD19 CAR-T细胞治疗后第30天及移植前评估微小残留病（MRD）均为阴性。②亲缘全相合移植2例，亲缘单倍型移植8例，抗CD19 CAR-T细胞治疗获得深度缓解至allo-HSCT中位时间为32.5（20～60）d。③10例患者获得造血重建，中性粒细胞植入中位时间为15（15～21）d，血小板植入中位时间为19（17～30）d。④预处理过程中，10例患者均未出现肝静脉闭塞病及出血性膀胱炎。1例患者出现渗漏综合征，予以限制入量、补充白蛋白及利尿等治疗后好转。移植过程中8例（80％）出现发热，均经抗感染治疗后好转。发生Ⅱ度急性移植物抗宿主病（aGVHD）2例，Ⅲ度aGVHD 1例；至随访截止9例存活患者中8例出现局限性慢性移植物抗宿主病。⑤中位随访262（150～540）d，预期1年总生存率为（90.0±1.0）％，无病生存率为（85.7±1.3）％。

结论

抗CD19 CAR-T细胞治疗达深度缓解后序贯allo-HSCT可作为难治B淋巴细胞白血病患者的可选治疗方案。