Development of Immunostimulatory Virotherapy Without Neurotoxicity for the Treatment of Brain Malignancies

项目总结 胶质母细胞瘤是所有恶性实体肿瘤中最致命和最顽固性的肿瘤之一。治疗方式有 二十年来没有明显改善。胶质母细胞瘤由于其固有的异质性而难以治疗， 一种降低其固有免疫原性的低突变负荷，以及一种高度免疫抑制 防止关键免疫细胞渗透的微环境。尽管免疫疗法已经改变了 现代癌症治疗中，胶质母细胞瘤患者通常没有表现出强大或持久的能力 反应，导致胶质母细胞瘤被归类为免疫学上的“冷”瘤。新疗法 这就迫切需要加强免疫治疗，增强抗肿瘤免疫反应。 溶瘤病毒疗法是治疗脑部恶性肿瘤和增强肿瘤反应的新平台 对于标准的治疗方法，包括免疫疗法，效果很差。重组修饰溶瘤法 病毒允许多方面和协同的治疗药物设计方法，直接摧毁肿瘤 通过靶向裂解，同时也以互补的方式表达免疫刺激转基因 加强免疫介导的肿瘤根除。Implicyte，Inc.已经开发出两种非神经毒性嵌合体 水泡性口炎病毒(VSV)选择性地感染和破坏胶质母细胞瘤细胞，但不正常 脑组织。这个病毒治疗平台有几个关键的创新：它没有神经毒性，使用安全 在大脑中；它可以被进一步改造来表达多种免疫刺激转基因；它有能力 破坏大脑中的继发性肿瘤；它可以躲避中和抗体，允许重新给药；它可以 针对多种癌症类型。在这里，我们建议进一步发展我们的新型非神经毒性嵌合体 通过改造VSV来表达免疫刺激转基因，这将显著增强 抗肿瘤免疫反应。在具体目标1中，我们将进一步改进Implicte的嵌合VSV病毒 用两个免疫刺激性转基因‘武装’它们。这些新病毒将在体外进行验证 细胞培养分析，以确保它们的复制和亲本病毒一样，对原代人类无毒 高水平表达免疫刺激性转基因。在特定的目标2中，我们将在体内使用 建立同基因小鼠模型，评估这些病毒的疗效和免疫刺激增强作用。在……里面 这些体内研究，我们预计免疫刺激转基因的表达将加速消除 肿瘤，提高总体存活率，并诱导第二次挑战的小鼠的免疫记忆 肿瘤。一旦这项研究完成，我们将有一个领先的临床候选者，可以推进到阶段 II支持的IND使能研究获得未来临床试验的批准。内皮细胞非神经毒性 溶瘤病毒疗法结合了直接的肿瘤溶解和抗肿瘤免疫反应，具有潜在的 不仅可以根治患者的肿瘤，还可以防止肿瘤复发。

PROJECT SUMMARY Glioblastoma is one of the most lethal and recalcitrant of all malignant solid tumors. Treatment modalities have not improved significantly in two decades. Glioblastoma is difficult to treat because of its inherent heterogeneity, a low mutational load that reduces its intrinsic immunogenicity, and a highly immunosuppressive microenvironment that prevents infiltration by critical immune cells. Although immunotherapy has transformed modern cancer treatment, patients with glioblastoma have generally not demonstrated strong or durable responses, leading to the classification of glioblastoma as an immunologically ‘cold’ tumor. Novel therapies that can augment immunotherapy and enhance the anti-tumor immune response are urgently needed. Oncolytic virotherapy is a novel platform for treating brain malignancies and potentiating tumors that respond poorly to standard therapeutic approaches, including immunotherapy. Recombinantly-modified oncolytic viruses permit a multifaceted and synergistic therapeutic drug design approach that directly destroys the tumor through targeted lysis, while also expressing immunostimulatory transgenes in a complementary manner that enhance immune-mediated tumor eradication. Implicyte, Inc. has developed two non-neurotoxic chimeric vesicular stomatitis viruses (VSV) that selectively infect and destroy glioblastoma cells, but not normal brain tissue. This virotherapy platform features several key innovations: it is non-neurotoxic and safe for use in the brain; it can be further engineered to express multiple immunostimulatory transgenes; it has the ability to destroy secondary tumors in the brain; it can evade neutralizing antibodies allowing for re-dosing; and it can target multiple cancer types. Here we propose to further advance our novel non-neurotoxic chimeric VSVs by engineering them to express immunostimulatory transgenes that will significantly enhance the anti- tumor immune response. In Specific Aim 1, we will further improve Implicyte’s chimeric VSV viruses by ‘arming’ them with two immunostimulatory transgenes. These novel viruses will be validated using in vitro cell culture assays to ensure they replicate as well as the parental viruses, are non-toxic to primary human neurons, and express the immunostimulatory transgenes at high levels. In Specific Aim 2, we will use in vivo syngeneic mouse models to evaluate the efficacy and immunostimulatory enhancement of these viruses. In these in vivo studies, we expect expression of the immunostimulatory transgenes to accelerate elimination of the tumor, improve overall survival, and induce immunological memory in mice challenged with a second tumor. Once this study is complete, we will have a lead clinical candidate that can be advanced to Phase II-supported IND-enabling studies to secure approval for future clinical trials. Implicyte’s non-neurotoxic oncolytic virotherapy, which combines direct tumor lysis with an anti-tumor immune response, has the potential to not only eradicate a patient’s tumor, but prevent its reoccurrence aswell.