Allogeneic T cells Transduced with an Anti-CD19 Chimeric Antigen Receptor

该项目的主要重点是一项临床试验，其中患者在异基因干细胞移植和至少一次标准供体淋巴细胞输注后复发或持续B细胞恶性肿瘤。这些患者都患有已被证明对所有标准疗法具有抗性的极晚期恶性肿瘤。该项目产生了一个摘要，在2011年的美国血液和骨髓移植学会和国际血液和骨髓移植研究中心串联会议上发表。2周前提交了一份描述本研究患者结果的手稿。我们正在进行一项临床试验，患者接受同种异体T细胞的输注，这些T细胞用γ逆转录病毒载体进行遗传修饰，以表达识别B细胞抗原CD 19的嵌合抗原受体（CAR）。本试验治疗的第一位患者是一名65岁的慢性淋巴细胞白血病（CLL）男性，他在HLA匹配的非亲缘供者造血干细胞移植后复发。复发后，患者接受了4次供体淋巴细胞输注（DLI），最大CD 3+细胞剂量为2.9x10e7/kg，然后接受了来自原始供体的第二次干细胞移植。在任何DLI或第二次移植后，白血病的客观缓解均未发生。第二次移植后5个月，当他的CLL进展时，患者接受了来自其无关移植供体的6.2x10e7（1x 10 e6个细胞/kg）同种异体抗CD 19-CAR转导T细胞的输注。39%的输注细胞表达抗CD 19 CAR，这些细胞以CD 19特异性方式产生干扰素γ和IL-2。患者没有接受任何其他疗法与CAR转导的T细胞联合。在CAR转导的T细胞输注后6至12天，患者出现发热、疲劳、轻度低氧血症和间歇性轻度低血压。血清镁、磷和尿酸升高，与肿瘤溶解综合征一致。心脏左心室功能下降，在末次随访时有所改善。患者的血液B细胞计数从CAR转导的T细胞输注前的286个细胞/微升降低到细胞输注后26天的0个细胞/微升。在CAR转导的T细胞输注之前，CLL细胞占患者多细胞骨髓的80- 90%。细胞输注后26天进行的骨髓活检显示骨髓细胞正常，几乎不存在B系细胞，并且没有CLL的证据。CT扫描显示，在CAR转导的T细胞输注后，多个淋巴结的大小减少了50%以上，但存在残留的淋巴结病。在T细胞输注后的第一周内，通过定量PCR在患者血液中未检测到CAR转导的细胞，但在输注后11天占血液单核细胞的0.98%。这些结果对于进一步开发抗CD 19-CAR表达T细胞作为同种异体干细胞移植后复发的治疗是令人鼓舞的。我们在这项临床试验中治疗了另外9名患者。CLL患者在输注1.5x106 CAR+ T细胞/kg后9个月获得完全缓解。另一例套细胞淋巴瘤患者在输注抗CD 19 CAR T细胞后实现了持续部分缓解。所有患者的毒性均可控，主要包括发热和轻度低血压。我们将继续招募更多的患者参加这项试验。我们正在获得关于每个患者的毒性和成功治疗的预测因素的重要信息。

The main focus of this project is a clinical trial in which patients that have relapsed or persistent B-cell malignancies after allogeneic stem cell transplantation and at least one standard donor lymphocyte infusion. These patients all have extremely advanced malignancies that have proven to be resistant to all standard therapies. The project resulted in one abstract that was presented at the American Society of Blood and Marrow Transplantation and The Center for International Blood and Marrow Transplant Research tandem meeting in 2011. A manuscript describing the results of patients on this study was submitted 2 weeks ago. We are conducting a clinical trial in which patients receive infusions of allogeneic T cells that are genetically modified with a gammaretroviral vector to express a chimeric antigen receptor (CAR) that recognizes the B-cell antigen CD19. The first patient treated on this trial was a 65 year-old man with chronic lymphocytic leukemia (CLL) who relapsed after HLA-matched unrelated donor hematopoietic stem cell transplantation. Following the relapse, the patient received 4 donor lymphocyte infusions (DLIs) with a maximum CD3+ cell dose of 2.9x10e7 per kg and then a second stem cell transplant from the original donor. An objective remission of the leukemia did not occur after any of the DLIs or the second transplant. Five months after the second transplant, when his CLL was progressing, the patient received an infusion of 6.2x10e7 (1x10e6 cells per kg) allogeneic anti-CD19-CAR-transduced T cells derived from his unrelated transplant donor. Thirty-nine percent of the infused cells expressed the anti-CD19 CAR, and the cells produced interferon-gamma and IL-2 in a CD19-specific manner. The patient did not receive any other therapy in conjunction with the CAR-transduced T cells. From 6 to 12 days after the CAR-transduced T cell infusion, the patient experienced fevers, fatigue, mild hypoxemia, and intermittent mild hypotension. Increases in serum magnesium, phosphorous, and uric acid consistent with tumor lysis syndrome occurred. A decrease in cardiac left ventricular function developed, which was improving at last follow-up. The patients blood B cell count decreased from 286 cells per microliter before the CAR-transduced T cell infusion to 0 cells per microliter 26 days after the cell infusion. Before the CAR-transduced T cell infusion, CLL cells made up 80-90 percent of the patients hypercellular bone marrow. A bone marrow biopsy performed 26 days after the cell infusion showed a normocellular marrow, nearly absent B-lineage cells, and no evidence of CLL. CT scans revealed a greater than 50 percent decrease in the size of multiple lymph nodes after the CAR-transduced T cell infusion, but residual adenopathy was present. CAR-transduced cells were not detected in the patients blood by quantitative PCR during the first week after the T cell infusion, but made up 0.98 percent of blood mononuclear cells 11 days after the infusion. These results are encouraging for further development of anti-CD19-CAR-expressing T cells as a treatment for relapse after allogeneic stem cell transplantation. We have treated 9 additional patients on this clinical trial. A patient with CLL has obtained a complete remission that is ongoing 9 months after infusion of 1.5x106 CAR+ T cells/kg. Another patient with mantle cell lymphoma achieved an ongoing partial remission after infusion of anti-CD19 CAR T cells. Toxicities have been manageable in all patients and consist mainly of fevers and mild hypotension. We continue recruit more patients for this trial. We are obtaining important information on toxicity and predictors of successful therapy with each patient.