Individualized monitoring of treatment response and resistance in patients with metastatic melanoma

项目摘要/摘要： 转移性黑色素瘤是一种致命的疾病，五年存活率低达20%。免疫治疗和分子生物学 靶向治疗可提高存活率，但不同患者的反应各不相同，而且受益往往是暂时的 导致疾病的发展。目前还没有确定的循环生物标记物来监测治疗反应。 患者内转移肿瘤之间的分子异质性(肿瘤内异质性)和治疗- 驱动的克隆进化使治疗的选择和时间安排复杂化，并限制了反应持续时间。 循环中无细胞血浆DNA(CtDNA)中的癌症突变水平与治疗密切相关 乳腺癌和结直肠癌的反应和疾病进展。该项目的目标是评估 基于ctDNA的血液检测在治疗监测和作为肿瘤复发的微创替代方案中的应用 转移性黑色素瘤患者的肿瘤基因分型活组织检查。这一目标将通过分析来实现 来自三个队列的转移性黑色素瘤患者的连续血浆、肿瘤和生殖系样本：1)a 完成抗PD1免疫治疗的临床试验；2)从抗癌组织中进行前瞻性收集 基因使能药物治疗黑色素瘤试验；以及3)一项前瞻性观察研究 亚利桑那州梅奥诊所，采用标准护理、免疫疗法和分子靶向药物治疗。 这项提案的具体目的是：1)评估ctdna作为监测生物标志物的临床有效性。 治疗反应；2)评价ctdna测序作为肿瘤活检的替代方法以指导治疗。 选择和3)确定获得性免疫耐药的基因组驱动因素。对于目标1，患者- 将使用肿瘤外显子组测序来识别特定的突变，然后进行有针对性的数字测序 量化ctDNA。治疗期间ctDNA水平的变化将与治疗的反应和进展进行比较。 用于评估临床有效性的影像检查。对于目标2，将评估血浆和肿瘤样本的一致性 对治疗前血浆DNA进行外显子组测序，并与肿瘤外显子组测序进行比较。为 目标3，在免疫治疗的疾病进展中出现的新的基因组变化将被识别使用 治疗后血浆DNA的外显子组测序。抗PD1获得性耐药的基因组驱动因素 将通过评估在疾病进展过程中反复改变的分子途径来识别抑制剂。 这群人。 在这个项目完成后，预计ctdna分析在黑色素瘤中的有用程度将有助于 肿瘤监测，作为选择患者的肿瘤再次活检的替代(和潜在改进) 作为研究获得性免疫疗法耐药性的一种方法，将被建立。

PROJECT SUMMARY/ABSTRACT: Metastatic melanoma is a lethal disease with a dismal 20% five-year survival. Immunotherapy and molecularly targeted treatments improve survival but responses vary across patients and benefits are often temporary due to disease progression. There are no established circulating biomarkers to monitor treatment response. Molecular heterogeneity between metastatic tumors within a patient (intra-tumor heterogeneity) and treatment- driven clonal evolution complicate choice and scheduling of treatments and limit duration of response. Circulating levels of cancer mutations in cell-free plasma DNA (ctDNA) strongly correlate with treatment response and disease progression in breast and colorectal cancer. The goal of this project is to assess the utility of a ctDNA-based blood test for treatment monitoring and as a minimally-invasive alternative to tumor re- biopsies for tumor genotyping in patients with metastatic melanoma. This goal will be pursued through analysis of serial plasma, tumor and germline samples from patients with metastatic melanoma from three cohorts: 1) a completed clinical trial of anti-PD1 immunotherapy; 2) prospective collection from the Stand Up To Cancer Genomically Enabled Medicine for Melanoma trial; and 3) a prospective observational study of patients at Mayo Clinic Arizona, treating with standard of care immunotherapy and molecularly targeted drugs. The specific aims of this proposal are 1) to assess clinical validating of ctDNA as a biomarker for monitoring treatment response; 2) to evaluate ctDNA sequencing as an alternative to tumor biopsies to guide treatment selection and 3) to identify genomic drivers of acquired resistance to immunotherapy. For Aim 1, patient- specific mutations will be identified using tumor exome sequencing, followed by targeted digital sequencing to quantify ctDNA. Changes in ctDNA levels during treatment will be compared with response and progression on imaging to assess clinical validity. For Aim 2, concordance of plasma and tumor samples will be assessed using exome sequencing of pre-treatment plasma DNA and comparison with tumor exome sequencing. For Aim 3, new genomic alterations arising at disease progression on immunotherapy will be identified using exome sequencing of post-treatment plasma DNA. Genomic drivers of acquired resistance to anti-PD1 inhibitors will be identified by evaluating molecular pathways recurrently altered at disease progression across the cohort. At completion of this project, it is anticipated that the extent to which ctDNA analysis is useful in melanoma for tumor monitoring, as an alternative to (and potential improvement) over tumor re-biopsies for patient selection and as an approach for investigating acquired resistance to immunotherapy, will be established.