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

项目4：项目总结 近年来，在治疗晚期黑色素瘤患者方面取得了显著进展，特别是 PD-1或PD-L1的抑制剂，导致生存时间延长和患者数量急剧上升 转移性黑色素瘤。然而，超过一半的患者对PD-1/-L1抑制剂没有反应，肿瘤重新生长 大约一半的患者在两年内会出现这种情况。因此，很有必要了解其发病机制。 我们将继续努力克服阻力，并制定克服阻力的新方法。一种有充分证据的机制 对PD-1/L1抑制剂的耐药是肿瘤浸润性T细胞(TIL)的缺乏。我们发现靶向肿瘤 抑制巨噬细胞集落刺激因子-1受体(CSF1R)导致肿瘤 T细胞非依赖性消退并诱导肿瘤坏死因子α、白介素1β、干扰素γ表达和中性粒细胞增加 招聘。同样，激活CD40的抗体也会导致巨噬细胞的调节和肿瘤的消退 并与CSF1R协同。当在小鼠身上一起使用时，这些治疗方法刺激T细胞依赖的抗- 肿瘤反应。我们假设三联疗法(CSF1R和PD1的抑制剂与CD40激动剂)可能是 甚至更有效地诱导对一度浸润性差和/或 被T细胞识别。我们将检验刺激先天免疫和获得性免疫的关键假设 导致比那些优先靶向T细胞或髓系细胞的免疫更强大的抗肿瘤免疫 独自一人。我们将利用一系列新的免疫活性小鼠模型来抵抗PD-1/PD-L1抑制剂 由耶鲁大学产生，其驱动程序突变模仿人类黑色素瘤(例如，BRAFV600E，NRASQ61R，CDKN2a缺失， PTen、P53和β-连环蛋白增益)。我们将研究CSF1R抑制剂和CD40激动剂的作用。 在没有PD-1抑制剂的情况下确定二联体和三联体方案在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，我们将研究对沙门氏菌敏感或抗性的机制。 各种组合，以促进对使用这些方案治疗的人类的预测性生物标记物研究。我们会 进行CSF1R单抗与CD40激动剂联合应用的I/IB期临床试验(目标3) 三联疗法的剂量递增，其中将包括添加nivolumab。最优方案的扩展 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 这在之前基于PD-1/PD-L1的方案上取得了进展。在这项试验中接受治疗的患者的肿瘤将 使用最先进的技术表征与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 将使我们能够在诊所和实验室之间来回穿梭，促进个性化的方法 肿瘤患者对PD-1/PD-L1抑制剂反应差。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.