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

这个项目的主要焦点是一项临床试验，在该试验中，在异基因干细胞移植后复发或持续的B细胞恶性肿瘤患者和至少一名标准供者淋巴细胞输注。这些患者都患有极晚期的恶性肿瘤，已被证明对所有标准疗法都有抵抗力。该项目产生了一份摘要，并在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提交。我们已经启动了一项临床试验，患者接受同种异体T细胞的输注，这些T细胞用伽马逆转录病毒载体进行基因改造，以表达识别B细胞抗原CD19的嵌合抗原受体(CAR)。这项试验中第一位接受治疗的患者是一名患有慢性淋巴细胞白血病(CLL)的65岁男性患者，他在人类白细胞抗原相合的非血缘供者造血干细胞移植后复发。复发后，患者接受了4次供者淋巴细胞输注(DLIS)，最大CD3+细胞剂量为每公斤2.9×10e7，然后进行第二次原始供者干细胞移植。在任何一次DLIS或第二次移植后，白血病的客观缓解都没有发生。第二次移植五个月后，当他的CLL进展时，患者接受了6.2x10e7(每公斤1x10e6个细胞)异基因抗CD19-CAR转导的T细胞的输注，该T细胞来自于他的非血缘关系的移植供者。39%的输注细胞表达抗CD19 CAR，并以CD19特异的方式产生干扰素-γ和IL-2。患者没有接受任何其他结合CAR转导的T细胞的治疗。在CAR转导的T细胞输注后6至12天，患者出现发热、乏力、轻度低氧血症和间歇性轻度低血压。血清镁、磷和尿酸的升高与肿瘤溶解综合征一致。心脏左心功能出现下降，在最后一次随访中有所改善。患者外周血B细胞计数从CAR转导T细胞输注前的286个/微升降至输注26天后的0个/微升。在CAR转导的T细胞输注前，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，也没有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，但仍存在残留的腺病。在T细胞输注后第1周，定量聚合酶链式反应未检测到CAR转导细胞，但在输注后第11天，CAR转导细胞占全血单个核细胞的0.98%。这些结果为进一步开发抗CD19-CAR表达的T细胞作为治疗异基因干细胞移植后复发的方法提供了鼓舞。在这项临床试验中，我们已经治疗了另外3名患者。这3例患者在输注抗CD19-CAR转导的T细胞后无明显反应。我们继续为这项试验招募更多的患者。我们正在获得有关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. We have initiated 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 3 additional patients on this clinical trial. These 3 patients did not have impressive responses after the infusion of anti-CD19-CAR-transduced T cells. We continue recruit more patients for this trial. We are obtaining important information on toxicity and predictors of successful therapy with each patient.