Development of a Bispecific Antibody Based Immunotherapy for Triple Negative Breast Cancer

双特异性抗体免疫治疗三阴性乳腺癌的研究进展 摘要/摘要 一种有前景的、用途广泛的癌症治疗方法是使用双特异性抗体(BsAb)进行免疫 信元重定向。在开创这一策略的两种临床批准的疗法中，bsAb药物起到了 T细胞(通过CD3结合)和肿瘤细胞(通过与肿瘤相关的结合)之间的分子桥 抗原，或TAA)。同时结合这两个靶点会导致T细胞介导的肿瘤细胞溶解。 这一策略的令人印象深刻的成功导致了类似的bsAb免疫疗法的开发 血液病和实体癌的种类繁多，导致超过15种药物处于活跃的临床试验中。三重 阴性乳腺癌(TNBC)是一种浸润性乳腺癌，定义为缺乏所需的三种不同的TAA 寻找可用的靶向乳腺癌治疗方法。TNBC缺乏强有力的TAA，导致缺乏 现代靶向治疗和糟糕的患者结果，因此开发新的TAA靶向治疗 用于TNBC的药物是一个重要的未得到满足的医疗需求。OncoTAb公司已经开发出一种专利抗体(TAB 004)，识别肿瘤特异性MUC1变异体(TMUC1)。这种抗体是 OncoTAb的Agkura个人评分诊断试验对多种TNBC细胞具有很高的特异性 台词。在这个方案中，我们将开发和测试一种基于bsAb的针对TAB来源的TNBC的免疫疗法。 004抗体。从历史上看，新型bsAb免疫疗法的发展依赖于抗体的使用。 碎片或复杂的后处理和纯化，这两者都会降低稳定性，阻碍 可制造性和延展性。为了缓解这些发展障碍，Dualogics，LLC 开发了一个名为OrthoMab的专有bsAb平台，该平台保留了 天然抗体，并与现有抗体序列兼容。使用OrthoMab平台，我们可以 快速生成一套大小、结合价和几何取向不同的bsAb分子；所有 它们已被证明可以调节bsAb免疫疗法的疗效。在本提案的具体目标1中 我们将产生并鉴定三种针对tMUC1和CD3的bsAb，每种抗体都具有独特的 药代动力学和功能特性(Ryan Hallett，Dualogics LLC)。在目标2中，我们将测量特异性 每种bsAb对TNBC细胞株的作用，并证明人PBMCs(Lloye)对肿瘤细胞的靶向性杀伤作用 Dillon，OncoTAb Inc.)在目标3中，我们将评估我们表现最好的bsAb的药代动力学特性。 在TNBC异种移植小鼠模型中确定剂量和评估疗效(如周，UNC-Charlotte)。这些 实验将验证tMUC1作为治疗TNBC的可行策略的T细胞重定向，并建立 第二阶段研究的基础，以进行进一步的临床开发和IND前研究。

Development of a Bispecific Antibody Based Immunotherapy for Triple Negative Breast Cancer. SUMMARY/ABSTRACT A promising and versatile approach to cancer treatment is the use of bispecific antibodies (bsAb) for immune cell redirection. In the two clinically approved therapies that pioneered this strategy, a bsAb drug acts as a molecular bridge between a T cell (via CD3 binding) and a tumor cell (via binding of a tumor associated antigen, or TAA). Simultaneous binding of both targets results in T cell mediated cytolysis of the tumor cell. The impressive success of this strategy has led to the development of similar bsAb immunotherapies for a wide variety of both hematological and solid cancers, resulting in over 15 drugs in active clinical trials. Triple negative breast cancer (TNBC) is an invasive breast cancer defined by a lack of the three distinct TAA required for available targeted breast cancer therapies. The lack of a robust TAA for TNBC has resulted in a dearth of modern targeted therapies and poor patient outcomes, and therefore development of novel TAA-targeted drugs for TNBC is a significant unmet medical need. OncoTAb Inc has developed a proprietary antibody (TAB 004) that recognizes a tumor specific variant of MUC1 (tMUC1). This antibody serves as the basis of OncoTAb’s Agkura Personal Score diagnostic test and has high specificity for a broad number of TNBC cell lines. In this proposal, we will develop and test a bsAb based immunotherapy for TNBC derived from the TAB 004 antibody. Historically, development of novel bsAb immunotherapies relies on the use of antibody fragments or complicated post-processing and purification, both of which can reduce stability, hinder manufacturability and prolong development. In order to alleviate these development hurdles, Dualogics, LLC has developed a proprietary bsAb platform, called OrthoMab, that retains the stability and manufacturability of native antibodies and is compatible with existing antibody sequences. Using the OrthoMab platform, we can rapidly generate a suite of bsAb molecules with varied size, binding valency, and geometric orientation; all of which have been shown to modulate the efficacy of bsAb immunotherapies. In Specific Aim 1 of this proposal we will generate and biophysically characterize three bsAb specific for tMUC1 and CD3, each with unique pharmacokinetic and functional properties (Ryan Hallett, Dualogics LLC). In Aim 2, we will measure specificity of each bsAb for TNBC cell lines and demonstrate targeted cytolysis of tumor cells by human PBMCs (Lloye Dillon, OncoTAb Inc.). In Aim 3, we will assess the pharmacokinetic properties of our top performing bsAb to determine dosing and evaluate efficacy in a TNBC xenograft mouse model (Ru Zhou, UNC-Charlotte). These experiments will validate T cell redirection by tMUC1 as a viable strategy for TNBC treatment and establish the basis of a phase II study to pursue further clinical development and pre-IND studies.