Development of a new treatment modality for melanoma brain metastases - Resubmission - 1

 描述(申请人提供)：脑转移(脑-M)被认为是一半的转移性黑色素瘤患者死亡的原因，并且大多数仍然是无法治愈的。此外，在这个治疗黑色素瘤更加有效的新时代，患有全身性疾病的患者经常能够存活足够长的时间，使黑色素瘤细胞能够侵入血脑屏障，建立脑-M。我们的中心假设是，黑色素瘤脑-M的辐射导致免疫检查点配体的上调，并使脑-M对免疫检查点抑制剂更敏感。然而，确定脑-M患者的最佳治疗组合受到以下严重限制：1)缺乏临床相关的人源化Brain-M临床前模型来测试合理的组合，这是进入临床试验的先决条件；2)对 辐射对人脑组织肿瘤免疫和/或免疫检查点配体的影响为了验证我们的假设，我们将建立一个新的临床前人源化黑色素瘤脑M模型。我们还将使用我们独特的黑色素瘤生物样本数据库来测试脑辐射对黑色素瘤脑-M的影响。我们的初步数据，使用我们独特的人类标本资源，表明黑色素瘤Brain-M的辐射与未辐射的Brain-M相比显著上调PD-L1。然而，我们的概念验证试点实验需要使用更大的样本量进行验证和验证。我们将通过追求以下目标来验证我们的假设：目标1：建立人源化的黑色素瘤Brain-M的临床前模型，并开发免疫检查点抑制剂抗PD1与辐射联合的潜力。我们建议开发一个人源化的黑色素瘤脑-M模型，正确地概括和解决人类免疫系统的特异性。然后，我们将在人源化的Brain-M小鼠模型中利用抗PD1作为放射治疗的免疫佐剂，测试全脑放射治疗(2GyX5)对黑色素瘤Brain-M的假设，即通过上调免疫检查点配体(例如，抗PD-L1)使肿瘤对免疫检查点抑制剂(例如，抗PD1)更敏感。我们将对肿瘤浸润性淋巴细胞(TIL)进行定量，检测免疫检查点及其配体的表达，并使用细胞因子珠阵列和ELISA法检测放射治疗对细胞因子产生的影响。目的：研究辐射对人黑色素瘤Brain-M细胞的免疫调节作用。我们将验证这样一种假设，即对大脑的辐射上调了人脑-M肿瘤组织中的免疫检查点配体，并改变了分泌的细胞因子的分布。我们将比较我们纽约大学黑色素瘤生物谱库中的两组脑-M组织：1)放射后切除的组织和2)以前没有暴露于脑辐射的切除组织。对这些人体样本的初步分析支持辐射后的脑-M上调PD-L1。进一步的免疫学参数将在这些脑-M样本以及来自相同患者的血清中进行测量，并与放射治疗的临床反应和结果相关。

 DESCRIPTION (provided by applicant): Brain metastasis (Brain-M) is considered the cause of death in half of metastatic melanoma patients and remains mostly incurable. Moreover, in this new era of more effective melanoma treatment, patients with systemic disease frequently survive long enough for melanoma cells to trespass the blood-brain barrier to establish Brain-M. Our central hypothesis is that radiation of melanoma Brain-M leads to up-regulation of immune checkpoint ligands and makes the Brain-M more responsive to immune checkpoint inhibitors. However, determining the best combination of therapies for patients with Brain-M is severely limited by: 1) A lack of clinically relevant humanized Brain-M preclinical models to test rational combinations, a prerequisite for moving into clinical trials, and 2) A limited understanding of the effect of radiation on tumor immunity and/or immune checkpoint ligands on Brain-M human tissues. To test our hypothesis, we will establish a novel preclinical humanized melanoma Brain-M model. We will also use our unique melanoma biospecimen database to test the effects of brain radiation on melanoma Brain-M. Our preliminary data, using our unique human specimen resources, demonstrate that radiation of melanoma Brain-M significantly up-regulate PD-L1 compared to non-radiated Brain-M. However, our proof of concept pilot experiment needs to be verified and validated using a larger sample size. We will test our hypothesis by pursuing the following aims: Aim 1: To develop a humanized preclinical model for melanoma Brain-M and exploit the potential of the combination of immune checkpoint inhibitor anti-PD1 with radiation. We propose to develop a humanized model of melanoma Brain-M that correctly recapitulates and addresses the specificity of the human immune system. We will then exploit anti-PD1 as an immunological adjuvant to radiation therapy in the humanized Brain-M mouse model, testing the hypothesis that whole-brain radiotherapy (2GyX5) to the melanoma Brain-M makes the tumor more responsive to immune check point inhibitors (e.g., anti-PD1) by up- regulating immune checkpoint ligands (e.g., anti-PD-L1). We will quantify tumor infiltrating lymphocytes (TILs), measure the expression of immune checkpoints and their ligands, and use cytokine beads array and ELISA to measure the impact of radiotherapy on cytokines produced. Aim 2: To characterize radiation-induced immune modulation of melanoma Brain-M in human specimens. We will test the hypothesis that radiation to the brain up-regulates immune checkpoint ligands in human Brain-M tumor tissues as well as changes the profile of secreted cytokines. We will compare 2 groups of Brain-M tissues in our NYU Melanoma biospecimen bank: 1) resected post-radiation and 2) resected with no previous exposure to brain radiation. Pilot analysis of these human samples supports that irradiated Brain-M up-regulate PD-L1. Further immunologic parameters will be measured in these Brain-M specimens as well as in sera from the same patients, as well as correlated with clinical response to radiation therapy and outcome.