Microbicide properties of RT inhibitor combinations

RT 抑制剂组合的杀菌特性

• 批准号: 8313935
• 负责人: MICHAEL A PARNIAK
• 金额: $ 43.96万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-10 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8313935
• 关键词: Antiviral Agents; Back; CD4 Positive T Lymphocytes; Cells; Cervical; Clinical Trials; Clinical assessments; Deoxyadenosines; Development; Disease; Drug Formulations; Drug resistance; Drug-sensitive; Economics; Educational process of instructing; Enzymes; Equilibrium; Evaluation; Film; Gel; Gender; Generations; HIV; HIV Infections; HIV drug resistance; HIV vaccine; HIV-1; Half-Life; Heterosexuals; In Vitro; Inequality; Infection; Kinetics; Lead; Local Microbicides; Mediating; Memory; Metabolism; Nucleosides; Nucleotides; Pharmaceutical Preparations; Phase; Poliomyelitis; Property; Risk; Sexual Transmission; Smallpox; System; Systemic Therapy; Tenofovir; Tissue Model; UC 781; Vaccines; Vagina; Variant; Virion; Virus; Woman; analog; anti-HIV microbicide; base; chemical property; cost effective; design; inhibitor/antagonist; innovation; macrophage; microbicide; non-nucleoside reverse transcriptase inhibitors; novel; preclinical efficacy; preclinical safety; prevent; research clinical testing; resistant strain; success; topical antiviral; transmission process; tripolyphosphate; uptake

DESCRIPTION (provided by applicant): Topical microbicides are an important strategy to minimize heterosexual transmission of HIV. Several single agent microbicides are in clinical trials, including one based on the nonnucleoside reverse transcriptase inhibitor (NNRTI) UC781 that we discovered as a potential microbicidal agent. However, combination microbicides may be preferable, yet only a single combination microbicide is currently under evaluation. There is also an urgent need to identify new pipeline microbicidal agents. We have found that the nucleoside RT inhibitor (NRTI) 4'-ethynyl-2-fluoro-deoxyadenosine (4'E-2FdA) provides a potent and prolonged barrier to HIV- 1 infection of cells in the subsequent absence of exogenous drug, a property previously only noted for NNRTI such as UC781. The "memory effect" barrier is imparted by 4'E-2FdA at drug levels orders of magnitude less than those needed for protection by the nucleotide tenofovir, currently in clinical assessment for microbicide use. We hypothesize that microbicides comprising combinations of different classes of highly potent RT inhibitors, namely the NNRTI UC781 and an NRTI such as 4'E-2FdA, will provide an optimal barrier to HIV-1 transmission. We therefore propose these Specific Aims for this R21/R33 phased innovation application: R21 Aim 1. To evaluate the in vitro (cell-based) microbicidal properties of NRTI and UC781 alone and in combination. These studies include assessment of antiviral activity and "memory effect" protection imparted by NRTIs and UC781 alone and in combination using primary cells (PBMCs, CD4+ T-cells, macrophages) and different HIV drug-sensitive and drug-resistant strains, isolates and clades. R21 Aim 2. To elucidate the mechanism of 4'E-2FdA (and analogs) induced protective barrier or "memory effect" in HIV susceptible cells. These studies include characterization of uptake, conversion to triphosphate and intracellular stability of the NRTI-TPs, as well as detailed kinetic evaluations of the NRTI substrate activity with enzymes involved in metabolism of the NRTIs. R21 Deliverables: Identification of a lead NRTI and two back-ups for use with UC781 for development as a combination microbicide. R33 Aim 1. To formulate the NRTI/NNRTI combinations selected in the R21 phase into an appropriate delivery system for vaginal topical use. NRTIs and NNRTIs have different chemical properties, thus appropriate delivery systems must be identified to enable incorporation and release of the active agents. We will prepare and evaluate both gel and rapidly dissolving film formulations for the combination microbicide. R33 Aim 2. To evaluate the anti-HIV microbicidal activity of formulated NRTI/NNRTI combinations in an ex vivo cervical explant tissue model. These studies will use a newly developed physiologically relevant polarized cervical tissue model to assess the impact of formulated microbicides alone and in combination on HIV transmission and infectivity. R33 Deliverables: Identification of an appropriate delivery formulation for the selected NRTI/NNRTI combination for entry into subsequent preclinical safety and efficacy studies.

描述（由申请人提供）：局部杀微生物剂是减少艾滋病毒异性传播的重要策略。几种单剂杀微生物剂正在进行临床试验，包括一种基于非核苷逆转录酶抑制剂（NNRTI）的UC 781，我们发现它是一种潜在的杀微生物剂。然而，组合杀微生物剂可能是优选的，然而目前只有一种组合杀微生物剂正在评估中。还迫切需要确定新的管道杀菌剂。我们已经发现，核苷RT抑制剂（NRTI）4 ′-乙炔基-2-氟-脱氧腺苷（4 ′ E-2FdA）在随后不存在外源性药物的情况下提供了对HIV- 1感染细胞的有效和延长的屏障，这是以前仅在NNRTI如UC 781中注意到的特性。“记忆效应”屏障是由4 'E-2FdA在比核苷酸替诺福韦保护所需的药物水平低几个数量级的药物水平下赋予的，目前在临床评估中用于杀微生物剂的使用。我们假设，包含不同种类的高效RT抑制剂，即NNRTI UC 781和NRTI如4 ′ E-2FdA的组合的杀微生物剂将提供对HIV-1传播的最佳屏障。因此，我们为R21/R33分阶段创新应用提出了这些具体目标：R21目标1。评价NRTI和UC 781单独使用和联合使用的体外（基于细胞）杀微生物特性。这些研究包括使用原代细胞（PBMC、CD 4 + T细胞、巨噬细胞）和不同的HIV药物敏感性和耐药性菌株、分离株和进化枝评估NRTI和UC 781单独和组合赋予的抗病毒活性和“记忆效应”保护。2.目的：探讨4 'E-2FdA（及其类似物）诱导HIV易感细胞产生保护屏障或“记忆效应”的机制。这些研究包括NRTI-TP的摄取、转化为三磷酸盐和细胞内稳定性的表征，以及NRTI底物活性与参与NRTIs代谢的酶的详细动力学评价。R21可降解物：确定一种主要NRTI和两种备用NRTI，用于与UC 781一起开发复合杀微生物剂。1.将在R21阶段选择的NRTI/NNRTI组合配制成适当的阴道局部使用的递送系统。NRTI和NNRTI具有不同的化学性质，因此必须确定适当的递送系统以使活性剂能够掺入和释放。我们将制备和评价组合杀微生物剂的凝胶和快速溶解膜制剂。2.评价NRTI/NNRTI复方制剂在离体宫颈外植体组织模型中的抗HIV杀微生物活性。这些研究将使用新开发的生理相关极化宫颈组织模型，以评估单独和联合使用配方杀微生物剂对艾滋病毒传播和传染性的影响。R33可燃物：确定所选NRTI/NNRTI复方制剂的适当给药制剂，以进入后续临床前安全性和疗效研究。