Development of Next-Generation Precision Medicine RNAi Therapeutics to Treat AML

开发治疗 AML 的下一代精准医学 RNAi 疗法

• 批准号: 10044943
• 负责人: STEVEN F DOWDY
• 金额: $ 40.56万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10044943
• 关键词: Acute Myelocytic Leukemia; Adult; Antibodies; Antibody-drug conjugates; Cell surface; Cells; Charge; Chromosomal translocation; Cleaved cell; Clinical; Cytoplasm; Development; Disease remission; Disease-Free Survival; Endosomes; Engineering; Gemtuzumab Ozogamicin; Genes; Genetic; Genome; Goals; Growth; Hematologic Neoplasms; Liver; MLL gene; MLL-AF9; MLLT3 gene; Malignant Neoplasms; Masks; Modeling; Monoclonal Antibodies; Normal Cell; Oncogenes; Oncogenic; Outcome; Patients; Pharmaceutical Preparations; Prodrugs; Property; RNA Interference; RNA Interference Therapy; Radioisotopes; Relapse; Small Interfering RNA; Therapeutic; Therapeutic Agents; Therapeutic antibodies; Tissues; Vertebral column; absorption; acute myeloid leukemia cell; anti-PD-1; antibody conjugate; base; care outcomes; chemical group; chemotherapy; falls; fusion gene; high risk; in vivo; inhibitor/antagonist; inorganic phosphate; leukemia; leukemia/lymphoma; mouse model; mutant; neoplastic cell; next generation; novel; pre-clinical; precision medicine; response; siRNA delivery; side effect; small molecule inhibitor; standard of care; success; targeted delivery; technology development; therapeutic target; young adult

ABSTRACT Acute myeloid leukemia (AML) is one of the most prevalent hematological malignancies. Unfortunately, due to a high relapse rate from chemotherapy, disease-free survival (DFS) remains at 40%. Greater than 80% of AMLs express high levels of the CD33 marker on their cell surface. Alternative therapeutic approaches, including Antibody-Drug Conjugate (ADC), anti-CD33 Mylotarg (gemtuzumab ozogamicin), and Radionuclide Antibody-Conjugates (RACs), have shown some promising results. However, both of these antibody therapeutic agents have significant side effects and suffer from indiscriminant killing of normal cells expressing CD33 as well as from killing normal cells due to non-specific tissue absorption and drug shedding. Unfortunately, AML also does not respond to anti-PD1 and PD-1L check-point inhibitors. Due to chromosomal translocations, the MLL gene fuses to many other genes, including the AF9 gene, resulting in MLL-fusion oncogenes that drive AML growth and survival. Expression of MLL- AF9 driver oncogene in AML has a particularly poor clinical outcome. Consequently, there is a great need to develop novel precision medicine therapeutics that selectively targets and kills only AML tumor cells based on their oncogenic genetic translocations, while sparing normal CD33 positive cells. RNA Interference (RNAi) responses have great potential to target MLL-AF9 and other MLL translocation fusion genes. Unfortunately, despite its promising therapeutic features, due to their requisite negatively charged phosphate backbone, siRNAs have no ability to enter cells and require a delivery agent. To tackle the RNAi delivery problem, we pioneered development of a next-generation RNAi trigger, called RiboNucleic Neutral (siRNN) prodrugs. siRNNs represent a “Prodrug” approach where the negative charge is directly neutralized by a bioreversible phosphotriester chemical group that is selectively cleaved off in the cytoplasm, but not outside of cells. The rate-limiting RNAi delivery step is escape from the endosome into the cytoplasm. To enhance endosomal escape, we will synthesize a next-generation endosomal escape domain (EED). We will target delivery of MLL-AF9 siRNN RNAi triggers to AML cells by conjugation to anti-CD33 antibodies, called Antibody-RNAi Conjugates (ARCs). The goal of this high risk/high gain technology development proposal is treat AML by generating precision medicine anti-CD33 Antibody-RNAi Conjugates (ARCs) that selectively target the MLL-AF9 fusion oncogene and kill AML cells based on their mutant genetics, but unlike ADCs and RACs, have no effect on CD33-positive normal cells.

摘要 急性髓系白血病(AML)是最常见的血液系统恶性肿瘤之一。不幸的是， 由于化疗的高复发率，无病生存率(DFS)保持在40%。更大 80%以上的急性髓细胞白血病细胞表面高表达CD33分子。另类疗法 方法包括抗体-药物结合物(ADC)、抗CD33 Mylotarg(Getuzumab Ozogamicin)、 和放射性核素抗体-结合物(RAC)，已经显示出一些有希望的结果。然而，这两个 这些抗体治疗剂有明显的副作用，并遭受不分青红皂白的杀伤力 表达CD33的正常细胞以及非特异性组织吸收所致的杀伤正常细胞 和脱毒。不幸的是，AML对抗PD1和PD-1L检查点也没有反应 抑制剂。由于染色体易位，MLL基因与许多其他基因融合，包括 AF9基因，导致MLL融合癌基因驱动AML的生长和生存。MLL-的表达 AF9癌基因在急性髓系白血病中的临床预后特别差。因此，有一个很大的 需要开发新的精准药物疗法，选择性地靶向和杀死AML肿瘤 基于致癌基因易位的细胞，而不包括正常的CD33阳性细胞。核糖核酸 干扰(RNAi)反应具有针对MLL-AF9和其他MLL易位的巨大潜力 融合基因。不幸的是，尽管它有很有希望的治疗特征，但由于它们所必需的负面影响 带电的磷酸骨架，siRNA不能进入细胞，需要递送剂。至 为了解决RNAi传递问题，我们率先开发了下一代RNAi触发器，称为 核糖核中性(SiRNN)前药。SiRNN代表了一种“前药物”方法，其中阴性的 电荷直接被生物可逆磷三酯化学基团中和，该基团选择性地 在细胞质内分裂，但不在细胞外。限速RNAi传递步骤是避开 内体进入细胞质。为了增强内体逃逸，我们将合成下一代 内体逃逸结构域(EED)。我们将靶向将MLL-AF9 siRNN RNAi触发器传递到AML细胞 通过与抗CD33抗体结合，称为抗体-RNAi偶联物(ARCS)。达到这个高度的目标 风险/高收益技术发展建议是通过产生抗CD33的精确药物来治疗AML 选择性靶向MLL-AF9融合癌基因并杀伤AML的抗体-RNAi结合物 基于突变遗传学的细胞，但不同于ADC和RAC，对CD33阳性没有影响 正常细胞。