Preclinical development of WP1066, an effective inhibitor of STAT3 activation for

描述（由申请人提供）：由于缺乏有效的CNS恶性肿瘤治疗剂，我们对脑癌产生了长期的科学兴趣，并导致我们先前发现和临床前开发了两种明显不同类别的其他小分子（拓扑异构酶II抑制剂-WP 744和肿瘤细胞代谢抑制剂-WP 1122），专门用于治疗CNS恶性肿瘤。目前，WP744在非常成功的I期研究之后正在进行II期临床试验。随后，我们将我们的兴趣集中在独特的分子靶点信号转导和转录激活因子3（STAT 3）上，并通过第一阶段SBIR赠款获得资金。我们非常有希望的结果，得到了我们众多出版物的支持，导致选择WP 1066进行进一步的临床前和临床开发，从而提交了该II期SBIR资助提案。 STAT 3是控制对肿瘤细胞的存活和增殖重要的广泛基因的转录的分子枢纽。P-STAT 3是多种实体瘤类型中最常活化的致癌蛋白之一，并且已显示在大多数人类癌症中持续活化。更具体地说，大量数据已经证明，通常静止的p-STAT 3途径的激活对于肿瘤发生是至关重要的，并且是许多恶性肿瘤（包括胃癌、肾癌、乳腺卵巢癌、鳞状癌、肝细胞癌、间变性大细胞淋巴瘤、黑素瘤和神经胶质瘤）中不良预后的预测因子。除了调节生长和增殖外，STAT还密切参与免疫功能的调节。我们已经确定了一些深刻的免疫抑制因子，包括TcR，免疫抑制细胞因子，和小胶质细胞，诱导T细胞无能的癌细胞的微环境。这一发现表明，即使对抗原靶标产生了强烈的全身免疫应答，但在遇到肿瘤微环境时，这些应答也将在功能上呈惰性。目前可用的免疫激活剂不足以克服这种免疫耐受和免疫抑制。然而，一种新的信号转导和转录激活因子3（STAT 3）的小分子抑制剂已在体内这种情况下表现出显著的免疫激活特性，并可用于与癌症患者的免疫疗法有效协同。 我们的新型STAT 3活化途径的小分子抑制剂WP 1066具有药物样特征，是口服生物可利用的，穿过血脑屏障，并在多种临床前肿瘤模型中显示出体内活性，包括免疫活化。鉴于这种高度的疗效，我们建议研究集中在IND指导的临床前开发这种新型的，第一种治疗CNS恶性肿瘤的药物。 本提案的具体目标是完成WP 1066的临床前试验，以快速启动首次人体临床试验，包括：1）生产API的放大合成和工艺开发，2）进一步确定WP 1066的作用机制、选择性、可能的抗性机制，3）确定WP 1066的口服安全性特征和吸收，4）合成和筛选WP 1066的推定代谢物的安全性和功效，5）开发和验证定量分析方法，6）定义ADME，7）确定剂量安排并进行安全药理学、毒理学和毒代动力学研究，以及8）编写WP 1066作为CNS恶性肿瘤治疗的IND申请。 公共卫生相关性：尽管在过去的三十年中采用了多种治疗策略，但多形性胶质母细胞瘤的总体生存时间仍然不到14个月。由于这些肿瘤的侵袭性及其与关键脑结构的相关性，完全的手术消融是不可能的，并且辅助治疗，如化疗和放疗，虽然需要，但对疾病的影响仍然很小。我们的SBIR I期研究结果表明，STAT 3激活抑制剂（如WP 1066）极有可能是CNS肿瘤局部环境中癌细胞死亡的有效诱导剂和免疫激活的正调节剂。

DESCRIPTION (provided by applicant): Lack of effective therapeutics for CNS malignancies led to our long term scientific interest in brain cancers and to our previous discoveries and preclinical development of two other small molecules of distinctly different classes (a topoisomerase II inhibitor-WP744 and an inhibitor of tumor cell metabolism-WP1122) specifically directed at the treatment of CNS malignancies. Currently, WP744 is in Phase II clinical trials following a very successful Phase I study. We have subsequently focused our interest on the unique molecular target Signal Transducer and Activator of Transcription 3 (STAT3) and obtained funding through a Phase I SBIR grant. Our very promising results, supported by our numerous publications, led to the selection of WP1066 for further preclinical and clinical development leading to submission of this Phase II SBIR grant proposal. STAT3 is a molecular hub controlling the transcription of a wide array of genes important to the survival and proliferation of tumor cells. P-STAT3 is among the most frequently activated oncogenic proteins in multiple solid tumor types and has been shown to be persistently activated in most human cancers. More specifically, a large body of data has demonstrated activation of the typically quiescent p-STAT3 pathway is crucial to tumorigenesis and a predictor of poor prognosis in many malignancies including gastric, renal, breast ovarian, squamous, hepatocellular carcinoma, anaplastic large cell lymphoma, melanoma and gliomas. In addition to regulating growth and proliferation, STATs are intimately involved in the regulation of immune function. We have identified a number of profound immunological suppressive factors including Tregs, immunosuppressive cytokines, and microglia that induce T cell anergy in the microenvironment of cancer cells. This finding suggests that even if a vigorous systemic immune response were generated to an antigen target, upon encountering the tumor microenvironment these responses would be rendered functionally inert. Currently available immune activators are insufficient to overcome this immune tolerance and immunosuppression. However, a novel small molecular inhibitor of the signal transducer and activator of transcription 3 (STAT3) has demonstrated marked immune activation properties in this setting in vivo, and could be employed to potently synergize with immunotherapies for patients with cancer. Our novel small molecule inhibitor of the STAT3 activation pathway, WP1066, possesses drug- like characteristics, is orally bioavailable, crosses the blood-brain barrier, and demonstrates in vivo activity, including immune activation, in a variety of preclinical tumor models. Given this high degree of efficacy we propose studies focused on IND-directed preclinical development of this novel, first in class drug to treat CNS malignancies. The specific aims of this proposal are focused on completion of preclinical testing of WP1066 in order to rapidly start the first in man clinical trials and include: 1) scale-up synthesis and process development for the production of API, 2) further determination of the mechanism of action, selectivity, possible resistance mechanisms of WP1066, 3) determination of the oral safety profile and absorption of WP1066, 4) synthesize and screen putative metabolites of WP1066 for safety and efficacy, 5) development and validation of a quantitative analytical methodology, 6) defining the ADME, 7) determination of dose-scheduling and performing safety pharmacology, toxicology, and toxicokinetic studies, and 8) writing the IND application for WP1066 as a treatment for CNS malignancies. PUBLIC HEALTH RELEVANCE: Despite multimodality therapeutic strategies employed over the past three decades, the overall survival time for glioblastoma multiforme is still less than 14 months. Due to the invasiveness of these tumors and their association with critical brain structures, complete surgical ablation is not possible and adjuvant therapy, such as chemotherapy and radiation therapy, while required still has minimal impact on the disease. Results from our SBIR Phase I studies indicated the strong likelihood that an inhibitor of STAT3 activation (such as WP1066) would be an effective inducer of cancer cell death and positive modulator of immune activation in the local environment of CNS tumors.