Engineered CD4 Tregs Targeting B-ALL and AML

项目总结/摘要 嵌合抗原受体（CAR）-T细胞疗法已经极大地改变了许多人的治疗模式。 癌症患者。然而，自体CAR-T细胞疗法的更广泛使用受到复杂的 物流、可变质量、T细胞耗竭、抗原逃逸和靶向/非肿瘤效应以及其他毒性， 比如CRS广泛的目标是通过开发一种安全有效的非处方药来解决这些问题。 架子细胞疗法为了实现这一点，我们提出了一种不同的细胞载体，特别是调节性T细胞 （Tennis）.（a）抑制促炎性细胞因子释放的固有能力， 细胞因子和宿主介导的同种异体排斥，和（B）大规模扩增的增殖能力， 基因工程，同种异体免疫效应细胞（IEC）治疗的理想特征。基于 先前在I/II期试验中测试的第三方TdR用于预防移植物抗 宿主疾病（GVHD）及其在临床前模型中的杀肿瘤效力，该策略解决了一些 同种异体IEC面临的巨大挑战。在目前的资助期间，在概念验证研究中，我们 证实了靶向CD 19+和CD 83+血液学的表达Treg的汽车的杀肿瘤活性。 恶性肿瘤。我们的中心假设是，同种异体THBE可以被工程化以增强持久性 并且与常规T细胞相比具有降低的不良副作用风险的最大肿瘤杀伤。 具体而言，我们将在最大耐受剂量下建立CAR 19 THBE的安全性特征， rhIL-2在复发/难治性CD 19+急性淋巴细胞白血病患者中的应用（Aim 1A，Aim 1B）， 体内药代动力学和持久性以及杀肿瘤活性。为了避免潜在的副作用， 我们将工程化CAR 19 T细胞以表达orthoIL 2 R β， 响应于orthoIL-2以最大化持久性和肿瘤杀伤（目的1C）。在目标2中，我们将测试效力 靶向AML细胞而非髓系祖细胞上的CD 83的nanoCAR T细胞（Aim 2A）。此外，为了 最大限度地减少紧张性刺激引起的Treg耗竭以及提高安全性，Tcirrhosis将被设计为具有 药物诱导型CAR允许控制其活化（Aim 2B）。这些IND赋能研究将支持 未来的临床试验冲击更安全、更有效的同种异体“现成”tTreg IEC的可用性 将解决一个关键的未满足的需求，克服个性化产品的一些主要限制。 1

PROJECT SUMMARY/ABSTRACT Chimeric antigen receptor (CAR)-T cell therapies have dramatically shifted the treatment paradigm for many patients with cancer. Broader use of autologous CAR-T cell therapies, however, is hindered by complicated logistics, variable quality, T cell exhaustion, antigen escape and on-target/off-tumor effects and other toxicities, like CRS. The broad objective is to address these issues by the development of a safe and effective off-the- shelf cell therapy. To accomplish this, we propose a different cellular vehicle, specifically Regulatory T Cells (Tregs). Advantages of Tregs include (a) an inherent ability to suppress the release of proinflammatory cytokines and host mediated allogeneic rejection, and (b) proliferative capacity for large-scale expansion and genetic engineering, ideal characteristics of an allogeneic immune effector cell (IEC) therapeutic. Based on the safety and efficacy profile of third party Tregs previously tested in phase I/II trials for prevention of graft-versus- host disease (GVHD), and their tumoricidal potency in preclinical models, this strategy addresses some of the grand challenges facing allogeneic IECs. During the current funding period, in proof of concept studies, we demonstrated the tumoricidal activity of Treg expressing CARs targeting CD19+ and CD83+ hematological malignancies. Our central hypothesis is that allogeneic Tregs can be engineered for enhanced persistence and maximal tumor killing with reduced risks of adverse side effects compared to conventional T cells. Specifically, we will establish the safety profile of CAR19 Tregs at the maximal tolerable dose without and with rhIL-2 in patients with relapsed/refractory CD19+ acute lymphocytic leukemia (Aim 1A, Aim 1B), assessing in vivo pharmacokinetics and persistence as well as tumoricidal activity. To avoid the potential side effects of systemic rhIL-2 and avoid bystander activation, we will engineer CAR19 Tregs to express an orthoIL2Rβ responsive to orthoIL-2 to maximize persistence and tumor killing (Aim 1C). In Aim 2, we will test the potency of nanoCAR Tregs targeting CD83 on AML cells and not myeloid progenitors (Aim 2A). Additionally, to minimize Treg exhaustion from tonic stimulation as well as enhance safety, Tregs will be engineered with a drug inducible CAR permitting control over its activation (Aim 2B). These IND enabling studies will support future clinical testing. IMPACT. The availability of safer and more effective allogeneic ‘off-the-shelf’ tTreg IECs would address a critical unmet need, overcoming some of the principal limitations of individualized products. 1