Project 2: Towards a safe and effective AML treatment strategy using anti-CD33 CAR T cells in combination with CAR-resistant hematopoietic stem cells

总结/摘要（项目2） 免疫疗法彻底改变了各种晚期恶性肿瘤的治疗。抗CD 19嵌合体 抗原受体重定向的T细胞（CART-19）在B细胞恶性肿瘤中特别成功。如何 将CART细胞疗法的成功转化为其他恶性肿瘤，如急性髓性白血病（AML） 仍然是该领域的一个重要问题。CART细胞疗法的关键要求是靶组织 可以牺牲AML是造血干/祖细胞（HSPC）的恶性肿瘤，并且与造血干/祖细胞（HSPC）共享细胞毒性。 与正常HSPC和与正常骨髓后代如嗜中性粒细胞和单核细胞接触。它 已经很清楚，缺乏AML特异性抗原是释放AML的最大障碍。 CART细胞对AML和其他骨髓恶性肿瘤的作用。该项目的长期目标是 通过创建AML特异性CART细胞，开发临床上可行的AML CART细胞平台， 在体内扩增并持续，以根除AML，同时保留正常的骨髓功能。核心假设 来自抗CD 33 CART细胞的持久抗白血病作用可以与足够水平的 基因工程CD 33缺陷型造血这将通过三个具体目标来实现。在Aim中 1、生产高质量的可耗竭抗CD 33 CAR T细胞。这些将是同种异体的， 用双顺反子慢病毒载体转导的T细胞，所述双顺反子慢病毒载体编码人源化抗CD 33 - 41 BB-zeta CAR作为 还有CD 20。在目标2中，将检测生产CD 33缺陷型人HSPC的可行性和安全性 并将获得生产CD 33缺陷HSPC的监管批准。在目标3中，将进行临床试验， 进行了合并CD 33缺陷型、CAR抗性同种异体HCT的联合方法， AML患者中的CART-33输注。这项研究将是重要的，因为它将有助于深入（ 临床反应）和广度（潜在的治愈性治疗的资格）的治疗武器库， 急性髓细胞白血病这项研究的创新之处在于取代了寻找合适的白血病特异性 抗原与一种新的平台，该平台将泛骨髓特异性CART（如CART-33）与输注组合， 供体HSPC经基因工程改造以缺乏CD 33，因此对CD 33杀伤具有抗性， CART-33

SUMMARY/ABSTRACT (PROJECT 2) Immunotherapy has revolutionized the treatment of a variety of advanced malignancies. Anti-CD19 chimeric antigen receptor redirected T cells (CART-19) have been particularly successful in B-cell malignancies. How to translate the success of CART cell therapy to other malignancies such as acute myeloid leukemia (AML) remains an important question in the field. A critical requirement of CART cell therapy is that the target tissue be expendable. AML is a malignancy of the hematopoietic stem/progenitor cells (HSPC) and shares cell surface antigens with normal HSPC and with normal myeloid progeny such as neutrophils and monocytes. It has become clear that the lack of AML-specific antigens is the single biggest impediment to unleashing the power of CART cells against AML and other myeloid malignancies. The long-term goal of this project is to develop a clinically feasible CART cell platform for AML, by creating AML-specific CART cells that are able to expand and persist in vivo to eradicate AML while preserving normal marrow function. The central hypothesis is that a durable anti-leukemic effect from anti-CD33 CART cells can co-exist with adequate levels of genetically engineered CD33-deficient hematopoiesis. This will be accomplished in three specific aims. In Aim 1, high quality depletable anti-CD33 CAR T cells will be manufactured. These will be allogeneic, donor-derived T cells transduced with a biscistronic lentiviral vector that encodes a humanized anti-CD33-41BB-zeta CAR as well as CD20. In Aim 2, the feasibility and safety of manufacturing CD33-deficient human HSPC will be tested and regulatory approvals to manufacture CD33-deficient HSPC will be obtained. In Aim 3, a clinical trial will be conducted of a combined approach incorporating CD33-deficient, CAR-resistant allogeneic HCT followed by CART-33 infusion in patients with AML. This research will be significant because it will contribute depth (of clinical responses) and breadth (of eligibility for potentially curative therapy) to the therapeutic arsenal against AML. The innovation of the proposed research lies in replacing the search for suitable leukemia-specific antigens with a novel platform that combines pan-myeloid specific CART (such as CART-33) with an infusion of donor HSPC that are genetically engineered to lack CD33 and which are therefore resistant to killing by CART-33.