SaefCAR: Regulatable CAR-T cells for safe and effective immunotherapy

SaefCAR：可调节的 CAR-T 细胞用于安全有效的免疫治疗

• 批准号: 10759600
• 负责人: Yemi Onakunle
• 金额: $ 40万
• 依托单位: MABSWITCH, INC.
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-19 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10759600
• 关键词: Address; Adverse event; Affinity; Animal Model; Antibodies; Antigen Targeting; Antigens; Architecture; Binding; Biological Products; CAR T cell therapy; CD19 gene; Calmodulin; Cell Line; Cells; Clinical; DNA; Discrimination; Disease; Dose; Engineering; Equilibrium; FDA approved; Flow Cytometry; Future; Hematologic Neoplasms; Human; Immunoglobulin Fragments; Immunotherapy; In Vitro; Letters; Libraries; Ligands; Modality; Patients; Peptides; Phase; Physiological; Proteins; Reaction Time; Regulation; Reporter; Retroviral Vector; Risk; Safety; Serious Adverse Event; Signal Transduction; Signal Transduction Induction; Small Business Innovation Research Grant; Solid Neoplasm; Specificity; T-Cell Activation; T-Lymphocyte; Technology; Tissues; Toxic effect; Tumor Antigens; Tumor Lysis Syndrome; Variant; Work; Writing; antigen binding; cancer immunotherapy; cancer type; chimeric antigen receptor; chimeric antigen receptor T cells; clinical translation; cytokine; cytokine release syndrome; delivery vehicle; design; engineered T cells; exhaustion; experience; improved; in vivo; neurotoxicity; preclinical development; premature; prevent; screening; small molecule; success; systemic toxicity; tumor

Project Summary: Despite the remarkable success in the treatment of some hematological cancers, the risk of serious adverse events and loss of potency remain major problems that threaten to curtail widespread application of chimeric antigen receptor (CAR) T-cell therapies to other cancer types including solid tumors. These problems, all of which are influenced by the binding affinity of the CAR targeting domain, result from the propensity for unpredictable hyperactivation that can lead to potentially fatal systemic toxicities such as cytokine release syndrome (CRS), tumor lysis syndrome (TLS) and neurotoxicity. Furthermore, on-target off-tumor toxicities can result from the indiscriminate binding of constitutively expressed CARs to tumor antigens on healthy tissues, whilst disease relapses can occur due to antigen escape and/or T cell exhaustion. Current and emerging CAR- T cell strategies and designs to address these problems are often too slow in terms of response times and onset of action. Furthermore, they prematurely and permanently eliminate the “high value” cells and often require the expression of additional proteins which may constrain the DNA payload capacity of current lenti- and retro- virus vectors. There is thus an urgent unmet need for in-vivo regulatable CAR-T cell platforms that are rapid, reversible and don’t exert a substantial DNA burden on the CAR delivery vector. The objective of this proposal is to assess the feasibility to regulate the activation, effector functions and cytokine release of CAR T-cells using an exogenously administered ligand that modulates the affinity of the CAR T-cell targeting domain. To this end we will utilize our proprietary universal allosteric-linker and switch module for antibodies (UNASMA) technology to incorporate an ON/OFF affinity switch into a well characterized antibody single chain variable fragment (scFv) against a clinically validated hematological cancer target which will subsequently be formatted as a switchable affinity chimeric antigen receptor (SaefCAR). We postulate that the resulting SaefCAR following transduction into a T-cell, will enable the in-vivo regulation of the SaefCAR T-cells’ activity via exogenous administration of a small molecule or peptide ligand, potentially solving several of the problems of current CAR-T cell therapies by: 1) Ameliorating intrinsic toxicities via enablement of a slow start to T-cell activation, 2) Preventing on-target off- tumor toxicities by switching off the CAR-T cell without eliminating it 3) Preventing exhaustion of tumor-specific CAR T cells caused by tonic signaling and other mechanisms via intermittent ON/OFF switching of the CAR. Specifically in Aim 1 we will develop switchable forms of the scFv which will subsequently be formatted into a CAR and transduced into a T-cell in Aim 2. In Aim 3 we will validate proof-of-concept of the regulated SaefCAR T-cells in in-vitro and in-vivo studies. We aim to demonstrate that a ligand-controllable affinity switch in the binding domain of SaefCAR T-cells can regulate it’s activation and effector functions against a tumor. Importantly due to the universal character of our approach, it provides a blueprint to improve any scFv-based CAR T-cell therapy in the future by adding a capability to regulate the CAR affinity for the tumor antigen.

项目总结： 尽管在一些血液病的治疗上取得了显著的成功，但严重不良反应的风险 事件和效力丧失仍然是威胁嵌合体广泛应用的主要问题 抗原受体(CAR)T细胞治疗其他类型的癌症，包括实体瘤。这些问题，所有的 它们受到CAR靶向域的结合亲和力的影响，这是由于 不可预测的过度激活，可能导致潜在的致命全身毒性，如细胞因子释放 综合征(CRS)、肿瘤溶解综合征(TLS)和神经毒性。此外，靶点上的肿瘤外毒性可以 由于结构性表达的CARS与健康组织上的肿瘤抗原不分青红皂白地结合， 同时，由于抗原逃逸和/或T细胞耗尽，疾病可能会复发。现有的和新兴的汽车- 解决这些问题的T细胞策略和设计在反应时间和发病时间方面往往太慢 行动的一部分。此外，他们过早地、永久地消除了“高价值”的细胞，并且常常需要 限制当前慢病毒和逆转录病毒DNA载量的额外蛋白的表达 向量。因此，对快速、可逆的体内可调节CAR-T细胞平台的迫切需求尚未得到满足 并且不要对汽车交付载体施加实质性的DNA负担。这项建议的目标是评估 An调节CAR T细胞活化、效应功能和细胞因子释放的可行性 调节CAR T细胞靶向结构域亲和力的外源性配基。为此，我们 将利用我们专有的抗体通用变构连接物和开关模块(UNASMA)技术来 将开/关亲和力开关引入具有良好特性的抗体单链可变区(ScFv) 针对临床验证的血液学癌症靶点，该靶点随后将被格式化为可切换的 亲和嵌合抗原受体(SaefCAR)。我们假设转导后产生的SAEFCAR 转化为T细胞，将能够通过外源性给药在体内调节SaefCAR T细胞的活性 小分子或多肽配体，通过以下方式潜在地解决当前CAR-T细胞疗法的几个问题： 1)通过使T细胞激活缓慢开始来改善固有毒性，2)防止靶向脱靶. 通过关闭CAR-T细胞而不是消除它的肿瘤毒性3)防止肿瘤特异性的耗尽 CAR T细胞通过CAR的间歇性开/关开关引起的强直信号和其他机制。 具体地说，在目标1中，我们将开发单链抗体的可切换形式，这些形式随后将被格式化为 在目标2中，我们将验证受调控的SaefCAR的概念验证 T细胞在体外和体内的研究。我们的目标是证明配体可控的亲和力开关在 SaefCAR T细胞的结合域可以调节其活性和抗肿瘤效应功能。重要的是 由于我们方法的通用性，它为改进任何基于scFv的CAR T细胞提供了蓝图 通过增加调节CAR对肿瘤抗原的亲和力的能力，在未来的治疗中。