Single and multi-component biguanide-based microbicides

描述（由申请人提供）：人类免疫缺陷病毒1型（HIV-1）感染的准物种性质，加上病毒在选择性药物压力下迅速变异的能力，导致多种药物联合使用成为治疗全身性HIV-1感染的公认范例。因此，为了获得一种安全有效的抗hiv -1杀菌剂，很可能会采用类似的方法。“局部杀微生物剂临床前综合项目”的长期目标是提供数据，帮助证明单独使用聚乙烯-六亚甲基双胍（PEHMB或PEHMB衍生产品）或作为联合用药方案的一部分进行临床开发和商业化的合理性。PEHMB是一种有效的HIV-1抑制剂，毒性很小，治疗指数为bb0 1400。作用机制研究表明，PEHMB的抗病毒活性是由于干扰病毒与细胞受体CXCR4和CCR5的结合。此外，PEHMB的大规模生产估计非常便宜（美元/公斤），并且我们发现PEHMB与正常阴道凝胶粘度增强剂非常相容且稳定。所有这些特性都足以保证对该化合物进行进一步的临床前评估。在初步研究中，我们还将PEHMB与其他类别的假定抗hiv -1杀菌剂结合使用，包括宾夕法尼亚州立医学院的Shengrund博士开发的硫酸树突状分子。我们建议在本项目中确定最佳的基于pehbb的候选药物组合，以最大限度地抑制HIV-1传播。该计划将包括三个研究项目整合到一个计划中。项目一将继续完善基于计算方法的PEHMB支架的抗病毒功效和细胞毒性参数，并结合我们的生化和生物测定系统的迭代反馈。此外，在项目1中，我们将纯化PEHMB，努力了解其结构，进行药代动力学和小鼠毒性研究，并开始用于体内实验和制造计划的预配方和配方工作。项目II的重要任务是利用体外和体内模型系统评估PEHMB的相对毒性，同时为我们理解PBG类化合物抑制病毒复制和引发细胞毒性的分子机制提供知识指导。项目二还将利用定义明确的动物模型，研究杀微生物剂对阴道内和宫颈免疫反应的影响。在项目ii中，我们将使用最先进的体外和体内模型系统来描述我们的先导化合物或组合的抗病毒功效。项目III将检查预配方参数，并在体外测试配方产品的功效，包括系统研究开发基于PEHMB的联合杀微生物剂，然后使用研究者开发的xenograph模型系统测试这些配方组合。三个项目中概述的所有努力都集中在提供将PEHMB及其可行组合从药物发现/开发管道的临床前阶段转移到临床阶段所需的信息，目标是提供一种具有特定作用模式的新型化合物，不同于目前处于临床试验中的其他化合物。

DESCRIPTION (provided by applicant): The quasi species nature of a human immunodeficiency virus type 1 (HIV-1) infection coupled with the virus's ability to rapidly mutate away from selective drug pressure has led to the use of multiple drugs in combination as the accepted paradigm for treating systemic HIV-1 infections. Therefore it is quite likely that to obtain a safe and effective anti-HIV-1 microbicide a similar approach will be employed. The long-term objectives this "Integrated preclinical program for topical microbicides", is to provide data that will help justify the clinical development and commercialization of polyethylene-hexamethylene biguanide (PEHMB or PEHMB-derived product) alone or as part of a combination regimen. PEHMB is a potent inhibitor of HIV-1 with minimal toxicity yielding a therapeutic index >1400. Mechanism of action studies has provided evidence that PEHMB's antiviral activity is due to interference with virus binding to the cellular receptors CXCR4 and CCR5. In addition, large-scale production of PEHMB is estimated to be extremely inexpensive (dollars/kg), and we have found PEHMB to be extremely compatible with and stable in normal vaginal gel viscosity building agents. All of these attributes are promising enough to warrant further preclinical evaluation of this compound. In preliminary studies we have also combined PEHMB with members of other classes of putative anti-HIV-1 microbicides including a sulfated dendrimer developed by Dr. Shengrund at Penn State College of Medicine. We propose in this Program to identify the best PEHMB-based combination of drug candidates to maximize the suppressive effect on HIV-1 transmission. This program will involve three research projects integrated into one program. Project I will continue to refine antiviral efficacy and cellular toxicity parameters of the PEHMB scaffold based on computational approaches coupled to iterative rounds of feedback from our biochemical and biological assay systems. In addition, in Project I we will purify PEHMB, work to understand its structure, perform pharmacokinetic and murine toxicity studies as well as begin pre-formulation and formulation work for use in in vivo experimentation and manufacturing schemes. Project II will have the important task of assessing the relative toxicity of PEHMB utilizing both in vitro and in vivo model systems while at the same time provide the intellectual lead in our understanding of the molecular mechanism(s) b y which the PBG class of compounds inhibit virus replication and elicit cellular toxicity. Project II will also examine the impact of microbicides on the intra-vaginal and cervical immune response utilizing well-defined animal models. In Project Ill, we will use state of the art in vitro and in vivo model systems to profile the antiviral efficacy of our lead compound or combination. Project III will examine preformulation parameters, and test the efficacy of the formulated products in vitro including systematic studies to develop combination microbicides based on PEHMB and then test these formulated combinations using xenograph model systems developed by the investigators. All of the efforts outlined in the three projects are focused on providing information needed to move PEHMB and its viable combinations from a pre-clinical to a clinical stage in the drug discovery/development pipeline, with the goal of offering a new class of compounds with specific mode of action distinct from other compounds currently in clinical trials.