Drug binding microprotein domains for targeted delivery of cytotoxic drugs

用于细胞毒性药物靶向递送的药物结合微蛋白结构域

• 批准号: 7269631
• 负责人: Volker Schellenberger
• 金额: $ 10.83万
• 依托单位: AMUNIX OPERATING, INC.
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-06 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7269631
• 关键词: Animals; Antibodies; Antineoplastic Agents; Binding; Blood Circulation; CD22 gene; Characteristics; Chemicals; Chemistry; Classification; Clinical Research; Complex; Condition; Coupling; Cytotoxic agent; Doxorubicin; Drug Exposure; Environment; Family; Goals; Lead; Libraries; Link; Malignant Neoplasms; Modality; Modification; Normal tissue morphology; Pan Genus; Phage Display; Pharmaceutical Preparations; Phase; Process; Property; Proteins; Purpose; Serum; Solutions; Specificity; Structure; System; TNFRSF8 gene; Testing; Therapeutic; Toxic effect; Tumor Antigens; Tumor Tissue; Validation; Variant; base; concept; cost; cytotoxic; density; design; design and construction; disulfide bond; experience; immunogenicity; improved; manufacturing process; scaffold; size; small molecule; targeted delivery; tumor; uptake

DESCRIPTION (provided by applicant): Targeted delivery of cytotoxic drugs to tumor tissues is an effective strategy to minimize drug exposure of normal tissues and thus improve the toxicity and efficacy profiles of these agents. A tumor targeting system consists of a tumor recognition moiety linked to a cytotoxic payload. Antibody-drug conjugates represent the most advanced form of this approach. These systems are dependent on the chemical conjugation of drug molecules to the targeting moieties through various linker chemistries. The need for chemical modification and coupling steps adds significant cost and complexity to the manufacturing process. Additionally, there remain concerns that the linkers may have inappropriate stability profiles, the drugs may not be released in their active states or in quantities needed to achieve efficacy, and the conjugation process will perturb mAb binding characteristics. We thus seek a universal solution that would circumvent the need for complex chemical conjugation processes and that would be directly applicable to a wide variety of targeting modalities. We envision a protein-based domain that would bind small molecule drugs non-covalently. The binding and stability profile can be directly customized to the environment where the drug is targeted for release. Importantly, these drug-binding domains can be genetically fused to targeting domains. Microproteins, which are very small proteins with high disulfide bond densities, possess distinctive properties which make them particularly suited for this purpose. Their unique structure allows the accommodation of large degrees of both sequence and structural diversity. Their small sizes, stability and non-immunogenicity are also attractive therapeutic attributes. As an initial proof of concept, which can be immediately extended to a therapeutic product concept, we propose to develop microprotein domains that can specifically bind the commonly used cancer drug, doxorubicin, and release it in acidic or reducing environments - conditions which prevail after intracellular uptake and not within the systemic circulation. We have designed and constructed 10 phage display libraries based on different microprotein scaffold families. The total diversity in these libraries exceeds 1011 unique sequences. We plan to test the feasibility of our approach through the systematic set of specific aims below. 1) Pan phage display libraries for microprotein-displaying phages which bind to immobilized doxorubicin. 2) Confirm ability of enriched microproteins to specifically bind to immobilized doxorubicin. Our goal is to identify at least 5 different lead variants. 3) Characterize binding properties and serum stability of the selected microproteins. Completion of these Phase I milestones will enable us to obtain important proof of concept and validation of our strategy for developing microproteins as drug-binding domains for targeted delivery of cancer therapeutics. Our ultimate goal would be to advance optimized microprotein drug-binding domains, which are fused to clinically important targeting moieties with specificity for tumor antigens such as CD22, CD30, or CD74, into clinical studies.

描述（由申请人提供）：将细胞毒性药物靶向递送至肿瘤组织是一种有效策略，可最大限度地减少正常组织的药物暴露，从而改善这些药物的毒性和疗效特征。肿瘤靶向系统由连接至细胞毒性有效载荷的肿瘤识别部分组成。抗体-药物缀合物代表了这种方法的最先进形式。这些系统依赖于药物分子通过各种接头化学与靶向部分的化学缀合。对化学改性和偶联步骤的需要显著增加了制造过程的成本和复杂性。此外，仍然存在以下问题：接头可能具有不适当的稳定性特征，药物可能不会以其活性状态或以实现功效所需的量释放，并且缀合过程将扰乱mAb结合特征。因此，我们寻求一种通用的解决方案，该解决方案将避免复杂的化学缀合过程的需要，并且将直接适用于各种各样的靶向模式。我们设想了一种基于蛋白质的结构域，它将非共价地结合小分子药物。结合和稳定性特征可以直接定制为药物靶向释放的环境。重要的是，这些药物结合结构域可以与靶向结构域基因融合。微蛋白是具有高二硫键密度的非常小的蛋白质，具有独特的特性，使其特别适合于此目的。它们独特的结构允许容纳大程度的序列和结构多样性。它们的小尺寸、稳定性和非免疫原性也是有吸引力的治疗属性。作为概念的初步证明，这可以立即扩展到一个治疗产品的概念，我们建议开发微蛋白结构域，可以特异性地结合常用的癌症药物，阿霉素，并释放它在酸性或还原环境-条件后，细胞内摄取，而不是在体循环中占主导地位。我们设计并构建了10个基于不同微蛋白支架家族的噬菌体展示文库。这些文库中的总多样性超过1011个独特序列。我们计划通过下面一系列系统的具体目标来测试我们的方法的可行性。1)结合固定化阿霉素的微蛋白展示载体的泛噬菌体展示文库。2)确认富集的微蛋白特异性结合固定化阿霉素的能力。我们的目标是确定至少5种不同的铅变体。3)表征所选微量蛋白的结合特性和血清稳定性。这些I期里程碑的完成将使我们能够获得重要的概念证明，并验证我们开发微蛋白作为靶向递送癌症治疗药物的药物结合结构域的策略。我们的最终目标将是推进优化的微蛋白药物结合结构域，其融合到临床上重要的靶向部分，对肿瘤抗原如CD 22，CD 30或CD 74具有特异性，进入临床研究。