Evaluation of Novel Dually Targeted Kinase Inhibitors for Therapy of Adult and Pediatric High-Grade Glioma

项目摘要 成人和儿童的高级别胶质瘤预后非常差，中位生存率低于 诊断后两年。表皮生长因子受体（EGFR）扩增和血小板衍生生长 因子受体（PDGFR）以及PI 3 K/AKT/mTOR途径中的突变很常见，并且可能是 通过基于激酶抑制剂的策略靶向。EGFR抑制已在临床上进行了测试，但反应还没有得到证实。 被限制。靶点参与不足，可能是由于血脑屏障功能不佳，以及 在复发性肿瘤中下调或绕过靶点，是由于缺乏 EGFR靶向药物的疗效。使用PI 3 K和MAPK抑制剂的联合策略很有希望，并且 可以克服GBM中对单一药剂的获得性耐药性。使用单个分子靶向的优点 多种激酶包括药物相互作用的风险降低，用于优化药物代谢的单一药代动力学特征， 剂量，并增加克服耐药性的潜力。因此，治疗学的发展 靶向不止一种激酶，识别反应的生物标志物和仔细评估BBB 渗透性对于改善患者结果至关重要。采用计算建模方法，我们 利用EGFR和PI3K的结构相关ATP结合位点抑制剂的已知结合模式， 设计小分子，以选择性的方式同时抑制两种激酶。我们假设 与多种药物相比，这种多药理学方法将在体外和体内提供更好的功效， 组合策略。在人胶质母细胞瘤和患者源性儿科中生成的初步数据 弥漫性内在脑桥胶质瘤（DIPG）细胞系显示了这些双重靶向药物的强效细胞毒性作用 相对于单独靶向EGFR或单独靶向PI3K。此外，我们已经确定了独特的代谢特征， 的抑制剂，表明抑制糖酵解途径和氧化磷酸化，这是不是 临床相关EGFR或PI3K抑制剂。我们认为，这将导致 基于代谢组学的生物标志物。在第1年，在此应用程序的R61阶段，我们将进一步优化 这一化学系列化合物的药物特性增加血脑屏障的可能性 (BBB)外显率我们已经生成了关键的初步数据，显示MTX-241具有关键属性， BBB通透性。因此，我们将使用体内模型来测试MTX-241，同时合成 并评估MTX-241的15 - 20种结构类似物。该提案的R33阶段将在 第2年和第3年，届时我们将专注于对已确定的两种最有希望的候选药物进行体内评价 使用原位模型来解决药物的抗肿瘤功效、血脑屏障渗透性和生物标志物 行动上这些研究旨在支持我们的假设，即具有双重特异性的单一抑制剂 EGFR和PI3K代表了复发性成人和儿童患者的基本原理和有前景的治疗策略， 具有高翻译潜力的HGG。

PROJECT SUMMARY High grade gliomas in both adults and children confer very poor prognosis, with median survival rates under two years post diagnosis. Amplification of epidermal growth factor receptor (EGFR) and platelet derived growth factor receptor (PDGFR), as well as mutations in the PI3K/AKT/mTOR pathway are frequent and can be targeted by kinase inhibitor based strategies. EGFR inhibition has been tested clinically, but responses have been limited. Inadequate target engagement, perhaps due to poor blood brain barrier penetrance, as well as downregulation or circumvention of the target in recurrent tumors, are amongst mechanisms cited for lack of efficacy of EGFR-targeted agents. Combination strategies using PI3K and MAPK inhibitors are promising, and can overcome acquired resistance to single agents in GBM. Advantages of using a single molecule to target multiple kinases include reduced risks of drug interactions, a single pharmacokinetic profile for optimization of dosing, and increased potential for overcoming drug resistance. Therefore, the development of therapeutics that target more than one kinase, identification of biomarkers of response and careful evaluation of BBB permeance are imperative to improving patient outcomes. Employing a computational modeling approach, we exploited the known binding modes of structurally related ATP binding site inhibitors of EGFR and PI3K to design small molecules that simultaneously inhibit both kinases in a selective manner. We hypothesize that this polypharmacology approach will provide better efficacy in vitro and in vivo compared to multi-drug combination strategies. Preliminary data generated in human glioblastoma and patient derived pediatric diffuse intrinsic pontine glioma (DIPG) lines shows potent cytotoxic effects of these dually targeted agents relative to targeting of EGFR alone or PI3K alone. Furthermore, we have identified unique metabolic features of the inhibitors, indicating suppression of both glycolytic pathways and oxidative phosphorylation, which is not seen with clinically relevant EGFR or PI3K inhibitors. We posit that this will lead to the development of metabolomics based biomarkers. In Year 1, in the R61 phase of this application, we will further optimize the pharmaceutical features of this chemical series of compounds to increase the likelihood of blood-brain barrier (BBB) penetrance. We have generated key preliminary data showing that MTX-241 possess critical attributes for BBB permeability. Therefore we will use in vivo models to test MTX-241, while simultaneously synthesizing and evaluating 15-20 structural analogs of MTX-241. The R33 phase of the proposal will be carried out in Years 2 and 3, whereupon we will focus on in vivo evaluation of the two most promising candidates identified using orthotopic models to address anti-tumor efficacy, blood brain barrier permeance, and biomarkers of drug action. These studies have been designed to support our hypothesis that a single inhibitor with dual specificity for EGFR and PI3K represents a rationale and promising treatment strategy for recurrent adult and pediatric HGG with high translational potential.