Abbreviated targeted therapy to improve anti-PD-1 inhibitor efficacy in melanoma

项目摘要/摘要 丝裂原活化蛋白激酶(MAPK)靶向治疗(MTT)目前被批准用于治疗转移瘤 存在BRAF致癌突变的黑色素瘤患者。抗PD-1抗体是 转移性黑色素瘤患者的标准一线治疗方法，无论是基因型，但反应 仅在40%-45%的患者中可见。为改善MTT法和抗PD1抗体的疗效，采取更有效的方法 都是需要的。我们最近证实，四甲基偶氮唑盐能增加肿瘤浸润性淋巴细胞(TIL)的数量， 克隆性和效应器功能，以及增加的免疫衰竭标志物，如PD-1，其配体PD-1- L1和TIM3。我们假设，这些与mtt相关的肿瘤微环境变化增强了免疫力。 在肿瘤微环境中的反应，并有可能转化为免疫无反应 肿瘤微环境转化为对后续抗PD1治疗更敏感的一种。为了检验我们的假设，我们 我已经开始了一项试验(NCT031429029)，它结合了MTT的引入阶段，即短暂的伴随阶段 四甲基偶氮唑蓝和抗PD-1单抗(Pembrolizumab)(Pbro)，然后是单药Pbro(目标1)。我们会 研究缩合四甲基偶氮唑蓝联合Pbro的临床受益率(CBR)，并确定 MTT对肿瘤免疫微环境的相关效应与24岁时CBR的改善有关 几周。作为试验的一部分，系列活组织检查(前处理、后四甲基偶氮唑盐导入法和四甲基偶氮唑盐加皮布罗)和 将采集外周血，我们的临床、翻译和基础研究团队将使用这些 样本，以确定与反应相关的生物标记物，并发展对 四甲基偶氮唑盐单独及联合抗PD-1抗体治疗对肿瘤微环境的影响。我们 还将评估抗PD-1和四甲基偶氮唑盐对GEMM黑色素瘤模型中T细胞反应的影响 患者(目标2)。我们将分析小鼠黑色素瘤模型中的T细胞亚群，评估 利用肿瘤再挑战研究控制肿瘤的小鼠的记忆T细胞。我们将描述T细胞的特征 在Aim 1的临床试验中登记的患者的反应，重点是效应器、记忆和 耗尽的T细胞亚群。最后，我们将研究长期患有黑色素瘤的患者的记忆力。 使用免疫检查点抑制剂或四甲基偶氮唑蓝治疗后的足月幸存者。最后，我们将把这些配对 用互补的小鼠黑色素瘤模型进行的转译研究，以确定该疗法如何影响 T细胞亚群的产生、功能和维持，并确定新的潜在治疗策略 体内CRISPR筛选小鼠黑色素瘤细胞。(目标3)

Project Summary/Abstract Mitogen activated protein kinase (MAPK)-targeted therapy (MTT) currently is approved for treating metastatic melanoma patients with tumors harboring an oncogenic mutation in BRAF. Anti-PD-1 antibodies are the standard front-line approach for patients with metastatic melanoma, regardless of genotype, but responses only are seen in 40-45% of patients. To improve outcomes with MTT and anti-PD1, more effective approaches are needed. We recently demonstrated that MTT leads to increased tumor infiltrating lymphocyte (TIL) number, clonality, and effector function, as well as increased immune exhaustion markers such as PD-1, its ligand PD- L1, and TIM3. We hypothesize that these MTT-associated tumor microenvironment changes enhance immune responses in the tumor microenvironment and have the potential to convert an immunologically non-responsive tumor microenvironment into one more responsive to subsequent anti-PD1 therapy. To test our hypothesis, we have opened a trial (NCT031429029) that incorporates a lead-in phase of MTT, a brief period of concomitant MTT and anti-PD-1 therapy with pembrolizumab (pembro), followed by single-agent pembro (Aim 1). We will investigate the clinical benefit rate (CBR) of abbreviated MTT in combination with pembro and determine if MTT-associated effects on the tumor-immune microenvironment are associated with improved CBR at 24 weeks. As part of the trial, serial biopsies (pretreatment, post-MTT lead-in, and on-MTT plus pembro) and peripheral blood will be collected, and our team of clinical, translational, and basic investigators will use these samples to identify biomarkers associated with response and to develop a mechanistic understanding of the effects of MTT alone and in combination with anti-PD-1 antibody therapy on the tumor microenvironment. We also will evaluate the effects of anti-PD-1 and MTT on T cell responses in a GEMM melanoma model and in patients (Aim 2). We will analyze T cell subsets in the mouse melanoma model, assessing the generation of memory T cells in mice that control tumors using tumor rechallenge studies. We will characterize T cell responses in the patients enrolled in the clinical trial in Aim 1, focusing on features of effector, memory, and exhausted T cell subsets. Lastly, we will examine memory populations in melanoma patients who are long- term survivors after treatment with immune checkpoint inhibitors or MTT. Finally, we will pair these translational studies with a complementary mouse melanoma model to determine how this therapy affects the generation, function and maintenance of T cell subsets, and identify new potential therapeutic strategies using in vivo CRISPR screens of mouse melanoma cells. (Aim 3)