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）感染的准种属性质，加上病毒在选择性药物压力下快速突变的能力，导致联合使用多种药物作为治疗全身性HIV-1感染的公认范例。因此，很有可能采用类似的方法来获得安全有效的抗HIV-1杀微生物剂。该“局部杀微生物剂的综合临床前计划”的长期目标是提供有助于证明聚乙烯双胍（PEHMB或PEHMB衍生产品）单独或作为组合方案的一部分的临床开发和商业化的数据。PEHMB是HIV-1的有效抑制剂，毒性最小，治疗指数>1400。作用机制研究提供了证据表明，PEHMB的抗病毒活性是由于干扰病毒与细胞受体CXCR 4和CCR 5的结合。此外，估计PEHMB的大规模生产是极其便宜的（美元/kg），并且我们已经发现PEHMB与正常阴道凝胶粘度构建剂极其相容并且在其中稳定。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价。在初步研究中，我们还将PEHMB与其他类型的推定抗HIV-1杀微生物剂的成员结合，包括由宾夕法尼亚州立大学医学院的Shengrund博士开发的硫酸化树状聚合物。我们在该计划中建议确定最佳的基于PEHMB的候选药物组合，以最大限度地抑制HIV-1传播。该计划将涉及三个研究项目整合到一个程序。项目I将继续完善PEHMB支架的抗病毒功效和细胞毒性参数，这些参数是基于计算方法以及来自我们的生化和生物测定系统的迭代反馈。此外，在项目I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，以及开始用于体内实验和生产方案的预配制和配制工作。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起细胞毒性的分子机制B提供智力指导。项目二还将利用明确定义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III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将检查预配制参数，并在体外测试配制产品的功效，包括开发基于PEHMB的复方杀微生物剂的系统性研究，然后使用研究者开发的异种移植模型系统测试这些配制的复方。这三个项目中概述的所有努力都集中在提供将PEHMB及其可行组合从临床前阶段转移到药物发现/开发管道中的临床阶段所需的信息，目的是提供一类新的化合物，其特定的作用模式与目前临床试验中的其他化合物不同。

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.