Integrating Diagnostics with Therapeutic Strategies in Chronic Myeloid Leukemia

描述（由申请人提供）：慢性髓性白血病（CML）提供了一种独特的疾病模型，其中应用转化方法研究疾病进展、治疗反应和疾病复发的生物学。虽然BCR-ABL的功能已被充分描述，但涉及疾病进展的事件在很大程度上仍不清楚。在过去的10年中，酪氨酸激酶抑制剂如甲磺酸伊马替尼（IM）已显着改变CML治疗。然而，尽管大多数早期慢性期（CP）患者的反应良好，但约20%的CP患者IM治疗失败。晚期CP患者的这一数字更高，晚期疾病或对IM耐药的疾病的结局明显较差。因此，明确需要早期识别处于疾病进展或治疗抗性风险中的患者。拟议的转化研究依赖于识别患者的风险因素，然后在独立患者中进行验证，最终目标是将这些发现应用于临床环境中的患者护理。这些研究的成功依赖于在足够多的患者中测试结果的能力。我们正在积极参与许多CML的临床试验，包括SWOG S 0325，该试验比较了标准剂量IM与高剂量IM和达沙替尼。在特定目标1中，将在400个独立患者样本中使用高通量定量RT-PCR（QPCR）验证先前在微阵列研究中鉴定的与CML疾病进展和治疗耐药性相关的诊断基因表达候选物。研究将扩大到使用所有目前已知的miRNAs的高通量QPCR分析来鉴定与CML进展和治疗抗性相关的microRNAs（miRNAs）。在特定目标2中，这些诊断研究将与接受酪氨酸激酶抑制剂（TKI）的患者的增强监测研究相结合。这些研究将包括早期检测和监测T315 I发展的动力学，T315 I是一种对所有目前批准的TKI具有抗性的突变。在维持最佳分子反应的患者中，还将使用新型纳米流体平台进行bcr-abl的增强QPCR监测，该平台通过将样品分配到多达10，000个独立反应中来增强灵敏度。T315 I点突变研究的目的是确定早期T315 I突变检测是否可用于指导治疗选择;在最佳分子学缓解患者中加强bcr-abl监测的目的是确定可能识别TKI治疗可以停止的患者的动力学特征。最后，在具体目标3中，我们将使用基于慢病毒载体的基因沉默和表达技术来检查PRAME和GLI 2在细胞系和原代细胞中的疾病进展和治疗抗性中的作用。一个主要目标将是确定参与进展和耐药性的新途径，这些途径可以通过现有疗法或新策略来靶向。这些综合生物学和临床研究的一个主要未来临床应用是确定可用于确定个体患者基于风险的治疗管理的特征。公共卫生相关性：尽管甲磺酸伊马替尼（格列卫，IM）治疗早期慢性期慢性粒细胞白血病（CML）患者取得了成功，但患有更晚期疾病或IM耐药疾病的患者的治疗结果仍然很差。我们发表的和初步的数据使我们能够在临床试验样本中研究几个可能改变我们如何管理CML的重要问题：我们能否定义反应的诊断预测因子;我们能否在治疗过程的早期识别泛耐药T315 I突变;我们能否确定最佳反应者的bcr-abl mRNA模式，从而识别一组可能能够停止治疗的患者;通过更好地了解CML进展的生物学，我们能否确定治疗的靶点和耐药的原因？这些发现将用于创建基于风险的概况，最终将用于个体患者的临床环境中，以定制治疗。

DESCRIPTION (provided by applicant): Chronic myeloid leukemia (CML) provides a unique disease model in which to apply a translational approach to the study of the biology of disease progression, therapeutic response, and disease relapse. Although the function of BCR-ABL is well described, events involved in disease progression remain largely unknown. Over the last 10 years, tyrosine kinase inhibitors such as imatinib mesylate (IM) have dramatically altered CML treatment. Yet despite the excellent responses in most early chronic phase (CP) patients, ~20% of CP patients fail IM therapy. This number is higher for late CP patients and outcomes for advanced disease or disease resistant to IM are significantly poorer. Thus, a clear need exists for the early identification of patients at risk for disease progression or therapeutic resistance. The proposed translational studies rely on the identification of risk factors in patients, followed by validation in independent patients, with the ultimate goal of applying these finding to patient care in the clinical setting. The success of these investigations relies on the ability to test the findings in a sufficiently large number of patients. We are actively participating in a number of clinical trials for CML, including SWOG S0325, which compares standard dose IM to high dose IM and to dasatinib. In Specific Aim 1 diagnostic gene expression candidates associated with CML disease progression and therapy resistance that were previously identified in microarray studies will be validated using high throughput quantitative RT-PCR (QPCR) in 400 independent patient samples. Investigations will be expanded to identify microRNAs (miRNAs) associated with CML progression and therapy resistance using high throughput QPCR profiling for all currently known miRNAs. In Specific Aim 2 these diagnostic studies will be integrated with enhanced monitoring studies in patients receiving tyrosine kinase inhibitors (TKIs). These investigations will include early detection and monitoring of the kinetics of T315I development, a mutation resistant to all currently approved TKIs. Enhanced QPCR monitoring of bcr-abl in patients maintaining the best molecular responses will also be performed using a novel nanofluidic platform that enhances sensitivity through sample partitioning into up to 10,000 independent reactions. The goal of the T315I point mutation studies is to determine whether early T315I mutation detection can be used to guide therapeutic choices; the goal of enhanced bcr-abl monitoring in the best molecular response patients is to determine a kinetic profile that may potentially identify patients in whom TKI therapy can be stopped. Lastly, in Specific Aim 3 we will examine PRAME and GLI2 for their role in disease progression and therapy resistance in cell lines and primary cells using lentiviral vector-based gene silencing and expression techniques. A main goal will be to identify new pathways involved in progression and resistance that can be targeted either by existing therapies or by novel strategies. A major future clinical application of these integrated biological and clinical studies is to identify profiles that can be used to determine risk-based treatment management in individual patients. PUBLIC HEALTH RELEVANCE: Despite the success of therapy with imatinib mesylate (Gleevec, IM) in early chronic phase chronic myeloid leukemia (CML) patients, treatment outcomes for patients with more advanced disease or IM resistant disease remain poor. Our published and preliminary data allow us to investigate in clinical trial samples several important questions that may change how we manage CML: can we define diagnostic predictors of response; can we identify the pan-resistant T315I mutation early in the treatment course; can we determine a bcr-abl mRNA pattern in the best responders that may identify a group of patients who may be able to stop therapy; and through a better understanding of the biology of CML progression can we identify targets for therapy and reasons for resistance? These findings will be used to create risk-based profiles that will ultimately be used in the clinical setting in individual patients to tailor therapy.