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

项目总结 成人和儿童的高级别胶质瘤预后非常差，中位存活率低于 确诊后两年。表皮生长因子受体(EGFR)扩增与血小板源性生长 因子受体(PDGFR)以及PI3K/AKT/mTOR通路中的突变是常见的，可以 以激酶抑制剂为基础的策略为靶点。EGFR抑制已在临床上进行了测试，但反应 是有限的。目标接触不足，可能是由于血脑屏障穿透性差，以及 在复发肿瘤中下调或规避靶点，是缺乏 EGFR靶向药物的疗效。使用PI3K和MAPK抑制剂的联合策略很有希望，而且 可克服GBM中对单一药物的获得性耐药性。使用单个分子打靶的优势 多个激酶包括降低药物相互作用的风险，优化药物的单一药动学曲线 剂量，并增加了克服耐药性的潜力。因此，治疗学的发展 以一种以上的激酶为靶点，识别反应的生物标记物并仔细评估血脑屏障 渗透性是改善患者预后的必要条件。采用计算建模方法，我们 利用已知的结构相关的EGFR和PI3K结合位点抑制剂的结合模式来 设计同时选择性地抑制两种激酶的小分子。我们假设 与多种药物相比，这种多药联用的方法在体外和体内都能提供更好的疗效 组合策略。人脑胶质母细胞瘤和患者衍生的儿科疾病的初步数据 弥漫性桥脑胶质瘤(DIPG)细胞系显示出这些双靶向药物的强大细胞毒作用。 相对于单独靶向EGFR或单独靶向PI3K。此外，我们还确定了独特的代谢特征 表明糖酵解途径和氧化磷酸化都受到抑制，而氧化磷酸化不是 与临床相关的EGFR或PI3K抑制剂一起出现。我们假定这将导致...的发展 以代谢组学为基础的生物标志物。在第1年，在此应用程序的R61阶段，我们将进一步优化 这一系列化合物的药学特性可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，表明MTX-241具有关键属性 对于血脑屏障渗透性。因此，我们将使用体内模型来测试MTX-241，同时合成 以及评估15-20个MTX-241的结构类似物。该提案的R33阶段将在#年进行 第二年和第三年，我们将重点放在体内评估两个最有希望的候选人确定 利用原位模型研究抗肿瘤疗效、血脑屏障通透性和药物生物标志物 行动。这些研究旨在支持我们的假设，即一种具有双重特异性的单一抑制剂 对于EGFR和PI3K来说，对于复发的成人和儿童来说，PI3K是一种合理和有前景的治疗策略 HGG具有很高的翻译潜力。

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.