Development of VN/14-1 and Related Analogs for Breast Cancer Therapy

描述（由申请方提供）：引言：流行病学证据强调了维生素A（视黄醇）及其活性代谢产物全反式维甲酸（ATRA）对人类乳腺癌和前列腺癌发病率的影响。ATRA是正常人乳腺上皮细胞适当分化所必需的。在一项对208名绝经后乳腺癌手术妇女进行的12年前瞻性研究中，最近报道低血浆视黄醇强烈预测患者预后较差。我们小组的工作已经确定了新的和有效的CYP 26酶抑制剂，该酶负责细胞内ATRA转化为非活性代谢物。这些CYP 26抑制剂也称为视黄酸代谢阻断剂（RAMBA）。我们的新型药物，除了抑制ATRA代谢，还具有多种理想的抗乳腺癌特性，因此被称为非典型RAMBA。我们的先导化合物4-（1）-（1H-咪唑-1-基）-（E）-视黄酸（VN/14-1）在几种内分泌敏感和不敏感（即，对主流乳腺癌疗法如他莫昔芬和芳香酶抑制剂有抗性的肿瘤）乳腺癌异种移植模型。VN/14-1还抑制N-甲基-N-亚硝基脲（MNU）诱导的雌激素受体（ER）阳性大鼠乳腺模型中的肿瘤生长，并拮抗雌二醇对子宫的刺激作用。与其对几种乳腺癌细胞系的作用相反，该化合物几乎没有生长抑制作用（浓度高达100？M）正常人乳腺上皮细胞和成纤维细胞。位于巴尔的摩的马里兰州大学（UMB，PI的前机构）已与英国癌症研究中心（CRUK）签订临床研究协议，进行VN/14-1的首次人体研究。位于巴尔的摩的切萨皮克生物发现管理有限责任公司（CBDM）最近从UMB获得了整个RAMBAs技术的许可。在另一个项目中，由本申请的PI发明的CYP 17抑制剂/雄激素受体调节剂VN/124-1（现称为TOK-001）最近获得FDA研究新药（IND）批准，用于前列腺癌患者的I/II期临床试验。虽然VN/14-1在大鼠中具有突出的口服生物利用度（%F >100%）和抗肿瘤功效，但其在小鼠和大鼠中分别具有0.34和1.41小时的短半衰期。因此，在本申请中，我们的目标之一是设计和合成具有改善的体内稳定性并具有如VN/14-1或更好的抗乳腺癌活性的新类似物。我们设想，这种药物将具有增强的功效和比VN/14- 1更大的治疗指数。此外，我们建议研究新的先导化合物和VN/14-1的两种对映体中的任一种的治疗潜力和作用机制，即，（+）和（-）-VN/14-1。该策略基于几个文献先例，这些文献先例表明手性化合物/药物中的对映异构体通常在其药代动力学（PK）、药效学（PD）和不良反应方面显示出显著差异。因此，了解单个异构体对效价、药物相似性和功效的影响非常重要，这样我们就可以避免其他异构体的不良反应（如果有的话）。假设：使用我们的先导外消旋VN/14-1，我们已经建立了这类RAMBA在人和鼠乳腺癌的许多体外和体内模型中的功效的原理证明。如本修订申请中所述，待测试的主要假设是开发（鉴定）第二代非典型RAMBA，具有增强的代谢稳定性、药物相似性和功效的VN/14-1的新类似物，可潜在地开发为乳腺癌的新疗法（抑制肿瘤生长和转移）。目的：为了验证这一假设，并最大限度地实现我们的最终目标，同时最有效地利用资源的可能性，我们将进行四个具体的目标：1）合成先导VN/14 -1的对映体并修饰VN/14-1以产生更有效/代谢稳定/有效的药物样类似物; 2）广泛表征和评估作为RAMBA和作为人乳腺癌细胞的抗增殖剂的新类似物; 3）确定先导化合物和最佳类似物在人乳腺癌细胞系中的作用机制;和4）为了测试先导化合物和最佳类似物抑制乳腺癌生长的能力，在体内抑制乳腺癌转移和鉴定功效标志物。重要性：我们的最终目标是发现和开发能够抑制肿瘤细胞生长和转移的新型口服活性药物。重要的是，非典型RAMBA抑制内分泌敏感性和内分泌抗性（内分泌疗法难治性）乳腺癌，并且还拮抗子宫增生，其特征与选择性雌激素受体调节剂（SERM）（例如他莫昔芬和芳香酶抑制剂（AI））的特征不同。如果成功进行，拟定的研究将确定至少一种或两种高度优化的、口服有效的非典型RAMBA，适用于乳腺癌治疗的高级临床前开发。这些研究还将导致识别在临床试验中有用的生物标志物。

DESCRIPTION (provided by applicant): Introduction: Epidemiological evidence highlights the influence of vitamin A (retinol) and its active metabolite, all-trans retinoic acid (ATRA) on the incidence of breast and prostate cancers in humans. ATRA is required for the appropriate cellular differentiation of normal human breast epithelial cells. In a 12-year prospective study of 208 postmenopausal women operated on for breast cancer, it was recently reported that low plasma retinol strongly predicts poorer prognosis in patients. Work by our group has identified novel and potent inhibitors of CYP26 enzymes responsible for intracellular catabolism of ATRA into inactive metabolites. These CYP26 inhibitors are also called retinoic acid metabolism blocking agents (RAMBAs). Our novel agents, in addition to inhibiting ATRA metabolism, also possess multiple desirable anti-breast cancer properties, and hence are called atypical RAMBAs. Our lead compound, 4-(1)-(1H-imidazol-1-yl)-(E)-retinoic acid (VN/14-1) exhibits exceptional anti-tumor efficacy in several endocrine-sensitive and insensitive (i.e., tumors that are resistant to mainstay breast cancer therapies such as tamoxifen and aromatase inhibitors) breast cancer xenograft models. VN/14-1 also inhibits the growth of tumors in the N-methyl-N-nitrosourea (MNU)-induced estrogen receptor (ER) positive rat mammary model and antagonizes the stimulatory effect of estradiol on the uterus. In contrast to its effects on several breast cancer cell lines, the compound exhibits virtually no growth inhibition (at concentrations up to 100 ?M) of normal human breast epithelial and fibroblast cells. The University of Maryland, Baltimore (UMB, the PI's former institution) has entered into a clinical research agreement with Cancer Research UK (CRUK) to conduct the first in human study of VN/14-1. Chesapeake BioDiscovery Management LLC (CBDM), Baltimore has recently licensed the entire RAMBAs technology from UMB. It may also be relevant to state here that in another project, a CYP17 inhibitor /androgen receptor modulator, VN/124-1 (now called TOK-001) invented by the PI of this application recently received FDA investigational new drug (IND) approval for phase I/II clinical trials in prostate cancer patients. Although VN/14-1 has outstanding oral bioavailability (%F >100%) in rat and anti-tumor efficacy, it has a short half-life of 0.34 and 1.41 hr, in mouse and rat, respectively. Therefore, in this application, one of our goals is to design and synthesize new analogs with improved in vivo stability and with anti-breast cancer activities as VN/14-1 or better. We envision that such agent would possess enhanced efficacy and a larger therapeutic index than VN/14- 1. In addition, we propose to investigate the therapeutic potential and mechanisms of action the new lead compounds and either of the two enantiomers of VN/14-1, i.e., (+) and (-)-VN/14-1. This strategy is based on several literature precedents which show that the enantiomers in a chiral compound/drug generally show significant differences in their pharmacokinetics (PK), pharmacodynamics (PD) and adverse reactions. Therefore, it is important to know the individual isomer effects on the potency, drug-likeness and efficacy so that we can avoid the adverse effects of the other isomer, if any. Hypothesis: Using our lead racemic VN/14-1, we have established proof-of-principle of the efficacy of this class of RAMBAs in many in vitro and in vivo models of human and murine breast cancers. The major hypothesis to be tested as described in this revised application is that development (identification) of 2nd generation atypical RAMBAs, new analogs of VN/14-1 with enhanced metabolic stability, drug-likeness and efficacy can potentially be developed as new therapy for breast cancer (inhibition of tumor growth and metastasis). Objectives: To test this hypothesis, and to maximize the probability of achieving our ultimate goal while using resources most efficiently, we will carry out four specific aims: 1) To synthesize enantiomers of lead VN/14-1 and to modify VN/14-1 to produce more potent/metabolically stable/efficacious drug-like analogs; 2) To extensively characterize and evaluate new analogs as RAMBAs and as anti-proliferative agents of human breast cancer cells; 3) To determine the mechanism of action of the lead compound and best analogs in human breast cancer cell line; and 4) To test the lead compound and best analogs for their ability to inhibit breast cancer growth, inhibit breast cancer metastasis in vivo and identify markers of efficacy. Significance: Our ultimate goal is to discover and develop new orally active drugs for breast cancer capable of inhibiting the growth of tumor cells and metastasis. Importantly, the atypical RAMBAs inhibit both endocrine- sensitive and endocrine resistant (refractory to endocrine therapies) breast cancers, and also antagonize uterine hyperplasia, characteristics that are distinct from those of selective estrogen receptor modulators (SERMs), such as tamoxifen and aromatase inhibitors (AIs). The proposed studies if successfully conducted will identify at least one or two highly optimized, orally efficacious atypical RAMBAs suitable for advanced preclinical development for breast cancer therapy. The studies would also lead to the identification of biomarkers that would be useful in clinical trials.