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，加上该病毒在选择性药物压力下快速变异的能力，导致使用多种药物组合作为治疗系统性艾滋病毒-1感染的公认范例。因此，为了获得安全有效的抗艾滋病毒-1杀微生物剂，很可能会采用类似的方法。这一“局部杀微生物剂综合临床前计划”的长期目标是提供数据，帮助证明聚乙烯-六亚甲基双胍(PEHMB或PEHMB衍生产品)单独或作为联合疗法的一部分的临床开发和商业化的合理性。PEHMB是一种有效的HIV-1抑制剂，毒性最小，产生的治疗指数为1400。作用机制研究提供的证据表明，PEHMB的抗病毒活性是由于干扰了病毒与细胞受体CXCR4和CCR5的结合。此外，大规模生产PEHMB估计非常便宜(美元/公斤)，我们发现PEHMB与正常的阴道凝胶增粘剂非常相容和稳定。所有这些属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微杀菌剂的成员结合起来，包括宾夕法尼亚州立医学院的Shengrund博士开发的一种硫酸化树枝状大分子。在这项计划中，我们建议确定基于PEHMB的最佳候选药物组合，以最大限度地抑制HIV-1传播的效果。这一计划将涉及三个研究项目，整合为一个计划。项目I将基于计算方法，结合我们的生化和生物检测系统的反复反馈，继续完善PEHMB支架的抗病毒效果和细胞毒性参数。此外，在项目I中，我们将提纯PEHMB，努力了解其结构，进行药代动力学和小鼠毒性研究，并开始预配方和配方工作，以用于体内实验和制造方案。项目II将承担利用体外和体内模型系统评估PEHMB的相对毒性的重要任务，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智力指导(S)。项目二还将利用明确定义的动物模型研究杀菌剂对阴道内和宫颈免疫反应的影响。在Project Ill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效果。项目III将检查配方前参数，并在体外测试配方产品的效力，包括开发以PEHMB为基础的组合杀菌剂的系统研究，然后使用研究人员开发的包裹体模型系统测试这些配方组合。这三个项目中概述的所有努力都集中在提供必要的信息，使PEHMB及其可行的组合物在药物发现/开发流程中从临床前阶段进入临床阶段，目标是提供一类具有特定作用模式的新化合物，有别于目前正在临床试验的其他化合物。

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.