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.

项目摘要 急性髓系白血病（acute myeloid leukemia，AML）是一种高度侵袭性的疾病，大多数AML患者最终成为难治性 化疗后死于恶性肿瘤由于AML的病因非常异质， 开发一种有效的方法来治疗大多数AML患者。使用嵌合抗原的免疫细胞疗法 表达CAR受体的T细胞非常成功地用于治疗淋巴细胞性白血病和淋巴瘤， 靶向CD 19，最近已被FDA批准用于临床。然而，类似的方法 尚未广泛探索以实现AML的成功。一个严重未满足的需求是开发新的 针对AML的方法，以改善治疗。我们最近开发了一种创新的系统， 结合AML细胞并使同源CAR T细胞能够杀死癌细胞的抗体。使用这个系统， 我们成功地从免疫的美洲驼中分离出了可以结合具有单一结构域的表位的纳米抗体。 两种纳米抗体特异性结合细胞表面蛋白酶，其在AML细胞中表达> 80%， 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细胞系来源的异种移植物中根除AML细胞。为了控制潜在的目标，偏离- 由于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 在体外和体内分裂CAR T细胞以杀死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），并且这种方法可以进一步发展以 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（Nb 157）导向的CAR T细胞对根除原发性人AML细胞的影响 临床前模型。目的2将改进和评估Nb 157导向的CAR，与其他AML相关的CAR结合。 联合抗原特异性分裂CAR T以增加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的安全的CAR系统， 可控地根除AML，为显著改善AML治疗铺平道路。