Stampidine: A Novel Broad-Spectrum Anti-HIV Microbicide

描述(申请人提供)：艾滋病作为一种通过性交传播的疾病的出现，促使人们寻找新的、有效的、安全的和女性控制的阴道杀菌剂来遏制粘膜病毒的传播。目前正在调查的杀微生物剂主要用于预防怀孕以及防止性传播疾病。对于(1)性活跃妇女在保护母婴免受艾滋病毒感染的同时允许怀孕，以及(2)作为预防性抗病毒制剂，特别是在开展辅助生殖技术手术前艾滋病毒-1血清不一致的夫妇而言，非杀精剂的供应同样重要。为了系统地鉴定一种广谱抗HIV杀菌剂，该杀菌剂可能能够在不影响生育的情况下防止HIV的性传播，我们合成了一系列司他夫定的苯基磷酸衍生物(STV/d4T)，并鉴定了司他夫定-5‘-(对溴苯基甲氧基丙氨酸磷酸酯)[Stampidine或STAMP]是最有效的广谱非杀精抗HIV药物。STAMP对非B包膜亚型HIV-1临床分离株的效力是STV/d4T的100倍，是齐多夫定(ZDV/AZT)的2倍。STAMP在亚纳摩尔到低纳摩尔浓度下抑制耐基因和表型核苷类似物逆转录酶抑制物(NRTI)和非核苷(NNRTI)耐药的HIV-1分离株的体外复制。口服STAMP在Hu-PBL-SCID小鼠体内对耐NRTI的临床HIV-1分离株(BR/92/019)显示出显著的体内抗HIV活性，且呈剂量依赖关系。单次口服50毫克/公斤的剂量或用STAMP治疗4周，可产生高于其IC50值的STAMP&GT；4-LOGS的治疗浓度，并在感染猫免疫缺陷病毒(FLV)的猫身上显示出强大的抗逆转录病毒活性。STAMP疗法与高达500毫克/公斤的剂量水平的毒性的任何临床或实验室证据无关。口服GMP级STAMP硬胶胶囊(25-100 mg/kg/天)后，STAMP在小鼠、狗和猫体内表现出良好的药代动力学行为。作为一种非杀精杀微生物剂，STAMP具有特殊的临床用途，可以防止与细胞相关的艾滋病毒-1从受感染的精液经性传播到女性生殖道。STAMP的进一步发展可能为旨在预防具有多药耐药性的艾滋病毒-1的性传播的新战略提供基础。这项第一阶段提案的目标是：(I)检测含有邮票的凝胶制剂在经阴道感染HIV-1的Hu-PBL-SCID小鼠中的杀菌活性；以及(Ii)经阴道FIV感染的猫艾滋病性传播模型。特异性目标1和2可能为STAMP在第二阶段研究中的临床开发提供基础，作为一种安全、有效的广谱抗艾滋病毒杀菌剂，而不具有受孕抑制功能。

DESCRIPTION (provided by applicant): The emergence of AIDS as a disease spread through sexual intercourse has prompted the search for new, effective, safe, and female-controlled vaginal microbicides for curbing mucosal viral transmission. Microbicides that are currently being investigated are directed mainly at preventing pregnancy as well as protection against sexually transmitted diseases. The availability of a non-spermicidal microbicide is equally important for (i) sexually active women to allow pregnancy while protecting both mother and child from HIV and; (ii) as a prophylactic antiviral agent, especially for HIV-1 serodiscordant couples before assisted reproductive technology procedures are undertaken. In a systematic effort to identify a broad-spectrum anti-HIV microbicide potentially capable of preventing the sexual transmission of HIV without affecting fertility, we have synthesized a series of phenyl phosphate derivatives of stavudine (STV/d4T) and identified stavudine-5'-(p-bromophenyl methoxyalaninyl phosphate) [Stampidine or STAMP], as the most potent broad-spectrum non-spermicidal anti-HIV agent. STAMP was 100-fold more potent than STV/d4T and 2-fold more potent than zidovudine (ZDV/AZT) against clinical HIV-1 isolates of non-B envelope subtype. STAMP inhibited the in vitro replication of genotypically and phenotypically nucleoside analog reverse transcriptase inhibitor (NRTI)-resistant and non-nucleoside (NNRTI)-resistant HIV-1 isolates at subnanomolar to low nanomolar concentrations. Orally administered STAMP exhibited significant and dose-dependent in vivo anti-HIV activity in Hu-PBL-SCID mice against a genotypically and phenotypically NRTI-resistant clinical HIV-1 isolate (BR/92/019). A single 50 mg/kg oral bolus dose or a 4-week treatment course with STAMP yielded therapeutic concentrations of STAMP >4-logs higher than its IC50 value and exhibited potent antiretroviral activity in feline immunodeficiency virus (FlV)-infected cats. STAMP therapy was not associated with any clinical or laboratory evidence of toxicity at dose levels as high as 500 mg/kg. STAMP exhibited favorable pharmacokinetic behavior in mice, dogs, and cats following oral administration of formulated GMP-grade STAMP (25-100 mg/kg/day) as hard gelatin capsules. STAMP has particular clinical utility as a non-spermicidal microbicide to prevent sexual transmission of cell-associated HIV-1 from infected semen to the female genital tract. The further development of STAMP may provide the basis for a new strategy aimed at prevention of the sexual transmission of multidrug-resistant HIV-1. The goals of this Phase I proposal are: (i) to examine the microbicidal activity of STAMP-containing gel formulation in vaginal HIV-1 infected Hu-PBL-SCID mouse; and (ii) vaginal FIV-infected cat models for sexual transmission of AIDS. Specific Aims 1 and 2 may provide the foundation for the clinical development of STAMP in Phase II studies as a safe, effective broad-spectrum anti-HIV microbicide without conception-inhibiting functions.