Developing bispecific CAR Ts for treating AML

开发用于治疗 AML 的双特异性 CAR T

• 批准号: 10044635
• 负责人: Xianxin Hua
• 金额: $ 41.72万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-06 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10044635
• 关键词: Acute Myelocytic Leukemia; Adoptive Cell Transfers; Antibodies; Antigens; Binding; CD19 gene; Cell Line; Cell Surface Proteins; Cell surface; Clinical; Drug resistance; Epitopes; Etiology; FDA approved; Hematopoietic stem cells; Human; Immunize; Immunotherapy; In Vitro; Leukemic Cell; Llama; Lymphoblastic Leukemia; Malignant Neoplasms; Mediating; Mus; Normal Cell; Normal tissue morphology; Patients; Peptide Hydrolases; Pre-Clinical Model; Refractory; Sampling; Specificity; System; T-Lymphocyte; Testing; Tissues; Toxic effect; Xenograft procedure; acute myeloid leukemia cell; alanine aminopeptidase; cancer cell; chemotherapy; chimeric antigen receptor; chimeric antigen receptor T cells; improved; in vivo; innovation; leukemia/lymphoma; leukemic stem cell; nanobodies; novel; novel strategies; outcome forecast; pre-clinical; success

Project Summary Acute myeloid leukemia (AML) is highly aggressive, and majority of AML patients eventually become refractory to chemotherapy and succumb to the malignancy. As etiology for AML is very heterogeneous, it is challenging to develop an effective approach to treat majority of AML patients. Adoptive cell therapy using chimeric antigen receptor (CAR)-expressing T cells is very successful for treating lymphocytic leukemia and lymphoma by targeting CD19, and has recently been approved by FDA for clinical use. However, the similar approach has not yet been extensively explored to achieve success for AML. A sorely unmet need is to develop new approaches to target AML to improve therapy. We have recently developed an innovative system to isolate antibodies that bind AML cells and enable the cognate CAR T cells to kill the cancer cells. Using this system, we successfully isolated nanobodies, which can bind epitopes with a single domain, from immunized llama. Two of the nanobodies specifically bind to a cell surface protease, which is expressed in AML cells from > 80% of AML patients. Notably, the CAR T cells targeting the cell surface protease potently and specifically eradicated AML cells in vitro and in AML cell line-derived xenograft. To control the potential on-target, off- tissue toxicity of the CAR T cells, we further developed a conditionally inducible CAR as well as bispecific and split CAR T cells to kill AML cells in vitro and in vivo. We hypothesize that the nanobody-directed CAR T system can eradicate AML patient derived xenografts (PDX), and this approach can be further developed to treat AML with tolerable toxicity. Two specific aims are proposed to test this hypothesis: Aim 1 will investigate the impact of the nanobody 157 (Nb157)-directed CAR T cells on eradicating primary human AML cells in preclinical models. Aim 2 will improve and evaluate the Nb157-directed CAR, in combination with other AML- associating antigen-specific split CAR T to increase AML-specific killing of the AML patient-derived leukemia cells, with reduced toxicity to normal cells. These studies will likely establish a novel and safe CAR system to controllably eradicate AML, paving the way to significantly improve AML therapy.

项目概要 急性髓系白血病 (AML) 具有高度侵袭性，大多数 AML 患者最终会变得难治 接受化疗并死于恶性肿瘤。由于 AML 的病因非常多样，因此具有挑战性 开发一种有效的方法来治疗大多数 AML 患者。使用嵌合抗原的过继细胞疗法 表达受体（CAR）的 T 细胞在治疗淋巴细胞白血病和淋巴瘤方面非常成功 靶向CD19，最近已获得FDA批准用于临床。然而，类似的方法已经 尚未得到广泛探索以取得 AML 的成功。一个严重未满足的需求是开发新的 靶向 AML 以改善治疗的方法。我们最近开发了一种创新系统来隔离 结合 AML 细胞并使同源 CAR T 细胞杀死癌细胞的抗体。使用这个系统， 我们成功地从免疫的美洲驼中分离出纳米抗体，它可以用单个结构域结合表位。 其中两种纳米抗体特异性结合细胞表面蛋白酶，该蛋白酶在 80% 以上的 AML 细胞中表达 AML 患者。值得注意的是，CAR T 细胞有效且特异性地靶向细胞表面蛋白酶 在体外和 AML 细胞系衍生的异种移植物中根除 AML 细胞。控制潜在的目标、脱靶 为了消除 CAR T 细胞的组织毒性，我们进一步开发了条件诱导型 CAR 以及双特异性和 裂解 CAR T 细胞以在体外和体内杀死 AML 细胞。我们假设纳米抗体导向的 CAR T 系统可以根除 AML 患者来源的异种移植物 (PDX)，并且该方法可以进一步开发用于 以可耐受的毒性治疗 AML。提出了两个具体目标来检验这一假设： 目标 1 将调查 纳米抗体 157 (Nb157) 定向 CAR T 细胞对根除原代人 AML 细胞的影响 临床前模型。目标 2 将结合其他 AML- 改进和评估 Nb157 导向的 CAR 联合抗原特异性拆分 CAR T 来增强对 AML 患者来源的白血病的 AML 特异性杀伤 细胞，对正常细胞的毒性降低。这些研究可能会建立一种新颖且安全的 CAR 系统 可控地根除 AML，为显着改善 AML 治疗铺平道路。