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

项目概要/摘要 丝裂原活化蛋白激酶（MAPK）靶向治疗（MTT）目前已被批准用于治疗转移性肝癌。 患有在BRAF中携带致癌突变的肿瘤的黑色素瘤患者。抗PD-1抗体是 转移性黑色素瘤患者的标准一线治疗方法，不考虑基因型，但缓解 仅见于40-45%的患者。为了改善MTT和抗PD 1的结果，更有效的方法 是必要的。我们最近证明，MTT会导致肿瘤浸润淋巴细胞（TIL）数量增加， 克隆性和效应子功能，以及增加的免疫耗竭标志物，如PD-1，其配体PD-1， L1和TIM 3。我们假设这些MTT相关的肿瘤微环境变化增强了免疫功能， 肿瘤微环境中的免疫应答，并有可能将免疫非应答性肿瘤转化为免疫应答性肿瘤。 将肿瘤微环境转化为对后续抗PD 1治疗更敏感的环境。为了验证我们的假设，我们 我已经开始了一项试验（NCT 031429029），该试验包括MTT的导入期，短暂的伴随治疗期， MTT和pembrolizumab（pembro）抗PD-1治疗，然后是单药pembro（Aim 1）。我们将 研究简化MTT联合pembro的临床获益率（CBR），并确定 MTT对肿瘤免疫微环境的相关作用与24小时CBR的改善相关 周作为试验的一部分，连续活检（治疗前、MTT导入后和MTT + pembro）和 将收集外周血，我们的临床、翻译和基础研究团队将使用这些血液。 样本，以确定与反应相关的生物标志物，并建立对 单独的MTT和与抗PD-1抗体疗法组合对肿瘤微环境的影响。我们 还将评估抗PD-1和MTT对GEMM黑色素瘤模型中T细胞应答的影响， 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T细胞亚群的产生。 记忆T细胞在小鼠中使用肿瘤再激发研究控制肿瘤。我们将描述T细胞 目标1中临床试验中招募的患者的反应，重点关注效应器，记忆和 耗尽的T细胞亚群。最后，我们将检查黑色素瘤患者的记忆人群，他们长- 免疫检查点抑制剂或MTT治疗后的长期存活者。最后，我们将这些 使用互补小鼠黑色素瘤模型的转化研究，以确定这种疗法如何影响 T细胞亚群的产生、功能和维持，并使用 小鼠黑色素瘤细胞的体内CRISPR筛选。(Aim第三章

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)