CLINICAL TRIALS USING TCR TRANSDUCED T CELL FOR ADOPTIVE IMMUNOTHERAPY

来自早期临床试验的越来越多的证据表明，过继性免疫治疗可以介导已建立的肿瘤的消退，并且许多这些消退可以持久。迄今为止，最有治疗潜力的肿瘤反应性T细胞的来源是TIL。不幸的是，TIL需要切除肿瘤病变，这对所有恶性肿瘤甚至黑色素瘤患者都是不可行的，许多患者都有不可切除的疾病。为了克服这一障碍，我们证明了正常PBL衍生的T细胞的特异性可以使用编码来自MART-1反应性T细胞克隆TIL 5的TCR a和p基因的逆转录病毒载体进行重定向。由此产生的TIL 5 TCR转导的T细胞培养物可以特异性识别装载MART-1肽的T2细胞和HLA-A2， MART-1黑色素瘤细胞。随后，TIL 5 TCR成为第一个用于治疗黑色素瘤患者的TCR基因修饰T细胞。虽然客观临床反应的数量很低，但这个I期试验和其他试验证明了产生TCR转导T细胞用于患者治疗的可行性，并且TCR转导T细胞可以安全使用。在过去的十年里，几十个TCR基因被克隆出来，并被鉴定出它们能够改造T细胞来识别病毒感染的细胞和肿瘤细胞。目前研究热点之一是TCR亲和力对抗原识别的影响。我们报道了一种独特的T细胞克隆（TIL 13S3I），一种MHC I类限制性CD4 T细胞，可以识别HLA-A2呈递的酪氨酸酶的免疫优势表位。TIL 13831 TCR随后被克隆，并在小鼠和人T细胞中被证明能够将不依赖cds的抗肿瘤活性转移到其他效应器上。TIL 13831 TCR具有高亲和性TCR的所有特性。表达TIL 13831 TCR （h3T）和TIL 13S3I TCR转导小鼠T细胞的转基因T细胞过继转移可以介导已建立的人和小鼠黑色素瘤的消退。这些使用高亲和力TCR的临床前小鼠结果和临床试验支持了高亲和力TCR优于低亲和力TCR的假设，用于TCR基因转移研究。在这个项目中，我们的假设是1)TCR转导的T细胞具有高亲和力，靶向酪氨酸酶，可以安全地给药于非清髓性化疗前的黑色素瘤患者，2)导致TCR转导T细胞持久性提高的因素将导致癌症患者治疗效果的提高。为了评估这些假设，我们将首先进行TIL 13831 TCR转导T细胞的I期剂量递增试验，然后进行II期试验，随机分配TIL 13831 TCR转导CDS +/- CD4+ T细胞的患者，以确定CD4 T细胞如何影响体内TCR转导CDS T细胞的持久性和功能。

There is mounting evidence from early stage clinical trials that indicate adoptive immunotherapy can mediate regression of established tumors and many of these regressions can be durable. So far, the source of tumor reactive T cells with the greatest therapeutic potential has been TIL. Unfortunately, TIL requires resection of tumor lesions which is not feasible for all malignancies and even for melanoma patients, many have unresectable disease. To circumvent this obstacle, we demonstrated that the specificity of normal PBL derived T cells can be redirected using retroviral vectors encoding the TCR a and p genes from the MART-1 reactive T cell clone TIL 5. The resulting TIL 5 TCR transduced T cell cultures could specifically recognize MART-1 peptide loaded T2 cells and HLA-A2 , MART-1 melanoma cells. Subsequently, the TIL 5 TCR was the first TCR used to treat melanoma patients with TCR gene modified T ceils. While the number of objective clinical responses were low, this phase I trial and others demonstrated the feasibility of generating TCR transduced T cells for patient treatment and that TCR transduced T cells could be administered safely. Over the past decade, dozens of TCR genes have been cloned and characterized for their ability to engineer T cells to recognize virus infected cells and tumor cells. One area of intense study has been the impact of TCR affinity on antigen recognition. We reported a unique T cell clone (TIL 13S3I), an MHC class I restricted CD4 T cell which recognized the immunodominant epitope from tyrosinase presented by HLA-A2. The TIL 13831 TCR was subsequently cloned and was shown in mouse and human T cells to be able to transfer CDS-independent anti-tumor activity to other effectors. This TIL 13831 TCR had all of the properties consistent with a high affinity TCR. Adoptive transfer of transgenic T cells expressing the TIL 13831 TCR (h3T) and TIL 13S3I TCR transduced mouse T cells can mediate regression of established human and mouse melanoma. These preclinical mouse results and clinical trials using high affinity TCRs support the hypothesis that high affinity TCRs are superior to TCRs with low affinity for TCR gene transfer studies. In this project, our hypotheses are 1) TCR transduced T cells bearing a high affinity TCR that targets tyrosinase can be administered safely to melanoma patients pretreated with non-myeloablative chemotherapy, and 2) factors that lead to improved persistence of TCR transduced T cells will lead to improved therapeutic efficacy in cancer patients. To evaluate these hypotheses, we will first conduct a phase I dose escalation trial of TIL 13S3I TCR transduced T cells followed by phase II trial randomizing patients between TIL 13831 TCR transduced CDS +/- CD4+ T cells to determine how CD4 T cells impact the persistence and function of TCR transduced CDS T cells in vivo.