Liposomal Disintegrin: Novel and Effective Antitumor Agent Phase I

描述（由申请人提供）：尽管乳腺癌的管理有了显著的改善，但晚期疾病的5年生存率仍然很低，大多数妇女最终会复发并死于疾病。因此，必须为这一毁灭性疾病开发新的治疗方式。这项I期STTR申请提出的研究将促进一种新型抗血管生成药物的临床转化，这种药物具有抗乳腺癌的有效抗肿瘤活性。为了解决这项技术临床转化的一个主要障碍，即依赖蛇毒来生产蛋白质，我们最近生产了一种重组形式的蛋白质，我们称之为vicrostatin (VN)；VN在体内和体外的活性与天然蛇毒蛋白逆转录抑素（CN）相当。我们的目标将集中在优化VN的生产和制备一种适合大规模生产和临床应用的脂质体VN （LVN）。我们将在人类乳腺癌小鼠模型中证明LVN单独或联合化疗的有效性。我们将用荧光素酶稳定转染乳腺癌细胞，并使用Xenogen小动物成像系统监测治疗期间肿瘤负荷和转移扩散。此外，我们将在啮齿动物模型中进行初步毒理学分析，以证明LVN的安全性。我们假设：(i) VN可以在适合生产cGMP的细菌细胞系中以可接受的生产水平生产；（ii） LVN可采用适合批量生产的均质化方法制备；（iii）在人类乳腺癌模型中静脉（IV）给药后，这样生产的LVN将具有与天然CN （LCN）相同的生物学功效；（IV） LVN将具有适合临床转化的毒理学特性。我们已经为成功完成该申请建立了以下具体目标和里程碑：具体目标#1 -制备足够数量的VN用于临床应用（里程碑1,0-6个月），并制备具有适当稳定性特性且量适合临床应用的VN （LVN）脂质体制剂（里程碑2,0-12个月）。特定目标#2 -在人类乳腺癌小鼠模型中证明LVN单独和与当前使用的化疗药物联合的生物学功效（里程碑3,9-12个月）。具体目标#3 -通过单剂量和剂量递增研究检查LVN在啮齿类动物中的毒理学特性（里程碑4,6-12个月）。在STTR的第二阶段，我们将继续进行临床前研究，包括进一步检查毒理学特性以确定LVN的安全性，表征其药代动力学和器官分布特征，并进一步检查LVN单独使用和与化疗药物联合使用的动物存活率和疗效。

DESCRIPTION (provided by applicant): Despite significant improvements in the management of breast cancer, the 5-year survival rate for advanced disease remains dismal, and a majority of women will eventually relapse and die from their disease. It is imperative, therefore, that new treatment modalities be developed for this devastating disease. This Phase I STTR application proposes studies that will facilitate the clinical translation of a novel antiangiogenic agent with potent antitumor activity against breast cancer. To address a major obstacle to the clinical translation of this technology, the reliance on snake venom to produce the protein, we have recently produced a recombinant form of the protein, which we call vicrostatin (VN); VN is as active as the native venom protein, contortrostatin (CN), in vitro and in vivo. Our aims will focus on the optimization of production of VN and preparation of a liposomal encapsulated form of VN (LVN) suitable for large scale production and clinical application. We will demonstrate efficacy of LVN alone or in combination with chemotherapy in a human mammary cancer mouse model. The mammary carcinoma cells will be stably-transfected with luciferase and we will use the Xenogen small animal imaging system to monitor tumor burden and metastatic spread during therapy. Additionally, we will carry out preliminary toxicological analysis in a rodent model to demonstrate safety of LVN. We hypothesize that: (i) VN can be made at acceptable production levels in a bacterial cell line suitable for cGMP production; (ii) LVN can be prepared by a homogenization method appropriate for mass production; (iii) LVN so produced will have biological efficacy identical to native CN (LCN) following intravenous (IV) delivery in a human breast cancer model, and (iv) LVN will have toxicologic properties suitable for clinical translation. We have established the following Specific Aims and milestones for successful completion of this application: Specific Aim #1 - Prepare VN in sufficient quantity for clinical application (Milestone 1, months 0-6), and prepare a liposomal formulation of VN (LVN) with appropriate stability characteristics and in amounts suitable for clinical application (Milestone 2, months 0-12). Specific Aim #2 - Demonstrate biological efficacy of LVN alone and in combination with a currently used chemotherapeutic agent in a mouse model of human breast cancer (Milestone 3, months 9-12). Specific Aim #3 - Examine toxicologic properties of LVN in rodents using single dose and dose escalation studies (Milestone 4, months 6-12). In Phase II of this STTR we will continue preclinical studies, which will include further examining toxicologic properties to determine safety of LVN, characterizing its pharmacokinetic and organ distribution profile, and further examining animal survival and efficacy of LVN alone and in combination with chemotherapeutic agents.