Clinical Trials using TCR Transduced T Cells for Adoptive Immunotherapy

来自早期临床试验的越来越多的证据表明，过继免疫治疗可以调解已建立的肿瘤的消退，并且这些消退中的许多可以持久。到目前为止，最具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来说都是不可行的，许多患者有无法切除的疾病。为了克服这一障碍，我们证明了利用编码MART-1反应性T细胞克隆TIL-5的TCRα和β基因的逆转录病毒载体可以重定向正常PBL来源的T细胞的特异性。由此得到的TIL-5 TCR转导的T细胞培养物能够特异性识别MART-1多肽负载的T2细胞和人类白细胞抗原A2、MART-1黑色素瘤细胞。随后，TIL-5TCR成为第一个用于TCR基因修饰T细胞治疗黑色素瘤患者的TCR。虽然客观临床应答的数量很少，但这项I期试验和其他试验证明了产生TCR转导的T细胞用于患者治疗的可行性，并且TCR转导的T细胞可以安全地使用。 在过去的十年里，数十个TCR基因被克隆并被鉴定为具有改造T细胞识别病毒感染细胞和肿瘤细胞的能力。TCR亲和力对抗原识别的影响一直是密集研究的一个领域。我们报道了一个独特的T细胞克隆(TIL 13S3I)，它是一种MHC-I类限制性CD4T细胞，它识别由人类白细胞抗原-A2呈递的酪氨酸酶的免疫优势表位。TIL 13831 TCR随后被克隆，并在小鼠和人类T细胞中显示能够将CDS非依赖的抗肿瘤活性转移到其他效应器。该TIL 13831热塑性弹性体具有与高亲和力热塑性弹性体一致的所有性质。过继转移表达TIL 13831 TCR(H3T)的转基因T细胞和转导TIL 13S3I TCR的小鼠T细胞可介导已建立的人和小鼠黑色素瘤的消退。这些临床前小鼠结果和使用高亲和力TCR的临床试验支持这样的假设，即在TCR基因转移研究中，高亲和力TCR优于低亲和力TCR。 在这个项目中，我们的假设是1)TCR转导的T细胞携带高亲和力的TCR靶向 酪氨酸酶可以安全地应用于接受非清髓性化疗的黑色素瘤患者，2)导致TCR转导的T细胞持久性改善的因素将提高癌症患者的治疗效果。为了评估这些假设，我们将首先对TIL 13831 TCR转导的T细胞进行I期剂量递增试验，然后在TIL 13S3I TCR转导的CD8+/-CD 4+T细胞之间随机进行II期试验，以确定CD4T细胞如何影响TIL 13S3I转导的CD8T细胞在体内的持久性和功能。

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 alpha and beta 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 CD8 +/- CD4+ T cells to determine how CD4 T cells impact the persistence and function of TCR transduced CD8 T cells in vivo.