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

该项目的主要焦点是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性b细胞恶性肿瘤患者的临床试验。这些患者都患有非常严重的恶性肿瘤，已被证明对所有标准疗法都有抗药性。2011年，在美国血液与骨髓移植学会和国际血液与骨髓移植研究中心的联合会议上，该项目产生了一份摘要。两周前提交了一份描述该研究患者结果的手稿。我们正在进行一项临床试验，患者接受输注同种异体T细胞，这些T细胞经过基因修饰，用逆转录病毒载体表达一种嵌合抗原受体（CAR），可以识别b细胞抗原CD19。该试验治疗的第一位患者是一名患有慢性淋巴细胞白血病（CLL）的65岁男性患者，他在接受hla匹配的非亲属供体造血干细胞移植后复发。复发后，患者接受4次供者淋巴细胞输注（DLIs），最大CD3+细胞剂量为2.9x10e7 / kg，然后接受第二次原供者干细胞移植。白血病的客观缓解并没有发生在任何的DLIs或第二次移植。第二次移植后5个月，当他的CLL进展时，患者接受了来自其非亲属移植供体的6.2x10e7（每公斤1x10e6个细胞）同种异体抗cd19 - car转导T细胞的输注。39%的注射细胞表达抗cd19 CAR，细胞以cd19特异性的方式产生干扰素- γ和IL-2。患者没有接受任何其他与car转导T细胞联合的治疗。car -转导T细胞输注后6 - 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。左心室功能下降，最后随访时有所改善。患者血液B细胞计数从car -转导T细胞输注前的每微升286个细胞下降到输注后26天的每微升0个细胞。在car转导的T细胞输注之前，CLL细胞占患者高细胞骨髓的80- 90%。细胞输注26天后进行的骨髓活检显示骨髓细胞正常，几乎没有b系细胞，没有CLL的证据。CT扫描显示，car转导的T细胞输注后，多个淋巴结的大小减少了50%以上，但存在残余的腺病。在T细胞输注后的第一周，通过定量PCR在患者血液中未检测到car转导细胞，但在输注后的第11天，car转导细胞占血液单个核细胞的0.98%。这些结果为进一步开发表达抗cd19 - car的T细胞治疗同种异体干细胞移植后复发提供了鼓舞。我们在这项临床试验中治疗了另外9名患者。一名CLL患者在输注1.5 × 106 CAR+ T细胞/kg后获得了持续9个月的完全缓解。另一名套细胞淋巴瘤患者在注入抗cd19 CAR - T细胞后获得了持续的部分缓解。所有患者的毒性都是可控的，主要是发烧和轻度低血压。我们将继续招募更多的患者参加这项试验。我们正在获得对每个病人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.