Novel Anti-CCR8 VHH for the Treatment of NSCLC

总结 免疫检查点抑制剂（ICI）疗法的出现极大地改变了免疫缺陷综合征的治疗前景。 非小细胞肺癌（NSCLC）。然而，大多数接受ICI治疗的患者要么是无应答者， 发展为进行性疾病（PD），尽管最初对治疗有反应。这背后的机制之一是， 抑制性免疫细胞群体在肿瘤微环境（TME）中的作用，例如调节性免疫细胞群体的免疫应答。 T细胞（Tcells），其作用是保护肿瘤免受患者免疫反应的影响。我们计划把目标对准 这些TME通过C-C趋化因子G蛋白偶联受体8（CCR 8）特异性地在TME内， 在活化的肿瘤驻留T淋巴细胞中选择性上调，并且在必需的效应T淋巴细胞中不存在。 预计选择性消除CCR 8 + TCR 4可促进针对NSCLC的更有效免疫应答 肿瘤，同时避免与非选择性消耗相关的危险的自身免疫副作用。 用抗体治疗剂靶向CCR 8和其他G蛋白偶联受体（GPCR）在历史上已经被证明是有效的。 一个挑战.这在很大程度上是由于使它们成为不良抗原的内在特性，包括它们的低 丰度、免疫原性差和构象异质性。为了解决这个问题，Abilita Bio开发了 使能膜蛋白（EMP™）定向进化技术，产生增强的GPCR变体 生物物理特性的变革性改进，同时保留其结构和生物学特性， 本案无关使用EMP™方法，我们进化出了构象稳定的CCR 8版本， 用作美洲驼免疫的蛋白抗原，以及发现VHH单域抗体家族， 独特地靶向野生型人受体的跨膜核心。我们的目标是利用这些 抗体的有利特性来构建具有同类最佳潜力的分子。在拟议阶段 在SBIR研究中，我们将完成抗体命中的彻底体外表征和优化，选择一个 引导分子，然后在新型CCR 8人源化NSCLC小鼠模型中进行体内功效研究 与竞争对手的抗体进行头对头比较，以显示其优越性。我们将实现这一目标 通过执行以下科学目标。目标1：我们将分析我们多样化的VHH命中集合， 体外结合特性和生物物理稳定性，然后选择最佳分子进行进一步研究。 特征化目的2：我们将在作用机制研究中描述抗体的药理学和效力 以选择用于体内研究的先导抗体。在目标3中：我们将测试我们的先导抗体在CCR 8中的体内功效。 NSCLC的人源化小鼠模型。据我们所知，这是针对CCR 8的第一个体内疾病模型研究。 本发明涉及一种治疗方案，其中人CCR 8将在功能性TME的背景下被靶向。成功 这项I期研究的完成将为这些新的治疗潜力提供关键的验证。 抗体和证据来支持我们最好的假设这些研究的结果将继续支持 计划进展和SBIR第二阶段赠款的未来申请，以支持完成临床前 发展

Summary The advent of immune checkpoint inhibitor (ICI) therapies has dramatically changed the treatment landscape for non-small cell lung cancer (NSCLC). However, most patients treated with ICIs are either non-responders or develop progressive disease (PD), despite an initial response to therapy. One of the mechanisms behind this, is the action of suppressive immune cell populations within the tumor microenvironment (TME) such as regulatory T cells (Tregs), which act to shield tumors from the patient's immune response. We plan to target and deplete these Tregs specifically within the TME through the C-C Chemokine G Protein-coupled Receptor 8 (CCR8), which is selectively upregulated in activated tumor-resident Tregs and is absent from essential effector T lymphocytes. Selective elimination of CCR8+ Tregs is anticipated to promote a more effective immune response against NSCLC tumors, while avoiding the dangerous autoimmune side effects associated with non-selective depletion. Targeting CCR8 and other G protein-coupled receptors (GPCRs) with antibody therapeutics has historically been a challenge. This is largely due to the intrinsic properties that make them poor antigens, which include their low abundance, poor immunogenicity, and conformational heterogeneity. To address this, Abilita Bio developed the Enabled Membrane Protein (EMP™) directed evolution technology, which generates enhanced GPCR variants with transformative improvements in biophysical properties, while preserving their structure and biological relevance. Using the EMP™ methodology, we evolved a conformationally stabilized version of CCR8, which was used as a protein antigen for llama immunization and the discovery of VHH single-domain antibody families that uniquely target the transmembrane core of the wild-type human receptor. Our goal is to leverage these antibodies' advantageous properties to construct a molecule with best-in-class potential. In the proposed Phase I SBIR research, we will complete a thorough in vitro characterization and optimization of antibody hits, select a lead molecule, and then perform in vivo efficacy studies in a novel CCR8-humanized mouse model of NSCLC in a head-to-head comparison with a competitor’s antibody to show superiority. We will accomplish this goal through the execution of the following scientific aims. Aim 1: we will analyze our diverse VHH hit collection for binding characteristics and biophysical stability in vitro, and then select the best molecules for further characterization. Aim 2: we will characterize antibody pharmacology and potency in mechanism of action studies to select a lead antibody for in vivo studies. In Aim 3: we will test in vivo efficacy of our lead antibody in a CCR8- humanized mouse model of NSCLC. This is, to our knowledge, the first in vivo disease model study for a CCR8 therapeutic program, where human CCR8 will be targeted in the context of a functional TME. Successful completion of this Phase I research will provide critical validation of the therapeutic potential for these novel antibodies and evidence to support our best-in-class hypothesis. Results of these studies will support continued program advancement and a future application for an SBIR Phase II grant to support the completion of preclinical development.