Project 4-Modulating Innate Immunity to Overcome Resistance to PD-1/PD-L1 Blockade

项目4：项目概要 近年来，在治疗晚期黑色素瘤患者方面取得了巨大进展，特别是在 PD-1或PD-L1抑制剂，导致生存期延长， 转移性黑素瘤然而，超过一半的患者对PD-1/-L1抑制剂没有反应， 大约有一半的患者在2岁时就出现了这种情况。因此，非常需要了解 并开发克服耐药性的新方法。一种有据可查的 对PD-1/L1抑制剂的抗性是肿瘤浸润性T细胞（TIL）的缺乏。我们发现，靶向肿瘤 通过抑制殖民地集落刺激因子1受体（CSF 1 R）， 以T细胞非依赖性方式消退，并诱导TNFα、IL-1β、IFNγ表达和中性粒细胞 招聘类似地，激活CD 40的抗体也导致巨噬细胞调节和肿瘤消退。 并与CSF 1 R协同作用。当在小鼠中一起使用时，这些治疗刺激T细胞依赖性抗- 肿瘤反应我们假设三联疗法（CSF 1 R和PD 1抑制剂与CD 40激动剂）可能是一种有效的治疗方法。 甚至更有效地引发对曾经浸润不良的肿瘤的抗肿瘤反应和/或 被T细胞识别。我们将测试刺激先天免疫和适应性免疫的关键假设 导致比优先靶向T细胞或骨髓细胞的那些更强大的抗肿瘤免疫 一个人我们将利用一系列新的PD-1/PD-L1抑制剂耐药性免疫活性小鼠模型， 在耶鲁产生的模拟人类黑色素瘤的驱动突变（例如，BrafV 600 E，NrasQ 61 R，Cdkn 2a缺失， Pten、p53和β-连环蛋白的增加）。我们将研究CSF 1 R抑制剂和CD 40激动剂与 在没有PD-1抑制剂的情况下，以确定双联体和三联体方案在具有PD-1抑制剂的小鼠模型中的活性和毒性。 不同的遗传背景（目标1）。在目标2中，我们将研究对抗生素敏感或耐药的机制。 各种组合以促进对用这些方案治疗的人的预测性生物标志物研究。我们将 进行CSF 1 R mAb联合CD 40激动剂的I/IB期临床试验（目的3），同时 三联方案的剂量递增将包括添加纳武单抗。扩大最佳方案 将使用西蒙两阶段设计进行。符合试验条件的患者将患有晚期黑色素瘤 在既往基于PD-1/PD-L1的治疗方案中发生进展。本试验治疗患者的肿瘤将 使用最先进的技术表征肿瘤相关的巨噬细胞亚群和TIL亚群。 合作团队、临床相关动物模型的可用性以及接触患者及其肿瘤的途径 因此，将使我们能够在诊所和实验室之间来回，促进个性化的方法， 对PD-1/PD-L1抑制剂反应差的肿瘤患者。这些研究的结果将有助于 在其他肿瘤类型中也克服了对PD-1/PD-L1抑制剂的耐药性。

PROJECT 4: PROJECT SUMMARY Dramatic progress has been made in recent years in treating patients with advanced melanoma, particularly with inhibitors of PD-1 or PD-L1, resulting in prolonged survival and a sharp rise in the number of patients living with metastatic melanoma. However, over half the patients do not respond to PD-1/-L1 inhibitors, and tumor regrowth is seen in about half the patients by two years. Thus, there is great need to understand mechanisms of resistance and to develop new approaches to overcome resistance. A well-documented mechanism of resistance to PD-1/L1 inhibitors is paucity of tumor infiltrating T cells (TILs). We have found that targeting tumor associated macrophages by inhibition of the colony stimulating factor-1 receptor (CSF1R) results in tumor regression in a T cell independent fashion and induces increased TNFα, IL-1β, IFNγ expression and neutrophil recruitment. Similarly, antibodies that activate CD40 also result in macrophage modulation and tumor regression and synergize with CSF1R. When used together in mice, these treatments stimulate a T cell-dependent anti- tumor response. We hypothesize that triple therapy (inhibitors of CSF1R and PD1 with CD40 agonists) may be even more effective at eliciting anti-tumor responses to tumors that were at one time poorly infiltrated and/or recognized by T cells. We will test the key hypothesis that stimulating both innate and adaptive immunity leads to more robust anti-tumor immunity than those that preferentially target T cells or myeloid cells alone. We will utilize a series of novel immune competent murine models of resistance to PD-1/PD-L1 inhibitors generated at Yale with driver mutations that mimic human melanomas (e.g., BrafV600E, NrasQ61R, loss of Cdkn2a, Pten, p53, and gain of β-catenin). We will study the effects of CSF1R inhibitors and CD40 agonists with and without PD-1 inhibitors to determine activity and toxicity of doublet and triplet regimens in murine models with various genetic backgrounds (Aim 1). In Aim 2 we will study the mechanisms of sensitivity or resistance to the various combinations to facilitate predictive biomarker studies for humans treated with these regimens. We will conduct a phase I/IB clinical trial (Aim 3) of a CSF1R mAb in combination with a CD40 agonist with concurrent dose escalation of a triplet regimen that will include the addition of nivolumab. Expansion of the optimal regimen will be conducted using a Simon two stage design. Patients eligible for the trial will have advanced melanoma that has progressed on prior PD-1/PD-L1 based regimens. Tumors from patients treated on this trial will be characterized for tumor associated macrophage subsets and TIL subsets using state-of-the-art technologies. The collaborative team, availability of clinically-relevant animal models and access to patients and their tumors will thus enable us to go back and forth between the clinic and the lab, facilitating personalized approaches for patients with tumors poorly responsive to PD-1/PD-L1 inhibitors. Results from these studies will be helpful for overcoming resistance to PD-1/PD-L1 inhibitors in other tumor types as well.