Project 3. Overcoming Melanoma Treatment Resistance with Cytokine Immunotherapy

项目3：项目总结 在过去的十年里，无法切除的黑色素瘤的治疗发生了重大变化，在这些变化中，基于免疫的 治疗极大地提高了总存活率。不幸的是，几乎一半的黑色素瘤患者没有。 预先对免疫检查点抑制剂(ICI)做出反应，其他人则会出现复发或耐药疾病 时间到了。因此，仍然迫切需要免疫疗法来刺激耐ICI黑色素瘤的免疫力。 为此，细胞因子具有强大的免疫刺激活性，使其具有吸引力，适合用于 与ICIS结合以克服耐药性。白介素18(IL-18)特别吸引人，因为IL-18 受体(IL-18R)在CD8肿瘤浸润性淋巴细胞中特异性上调，并广泛表达于 自然杀伤(NK)细胞。然而，重组IL-18的临床试验没有成功，可能是由于表达上调 内源性IL-18受体拮抗剂或IL-18结合蛋白，IL-18BP抑制 IL-18的免疫刺激作用。因此，Ring实验室创造了IL-18的工程化版本 对IL-18BP具有抵抗力，但完全保留激活IL-18R的能力。一种临床级“抗诱饵”IL-18 (DR18)已由耶鲁大学开发并授权给Simcha治疗公司(ST-067)。ST-067是 目前正在进行首次人类临床试验，作为单一疗法进行研究。在临床前模型中，DR18 与抗PD-1有协同作用。此外，在小鼠模型中，DR-18在治疗耐ICI的MHC方面非常有效 I类缺陷肿瘤，与IL-18也激活NK细胞的能力一致。我们假设 DR-18与免疫检查点抑制剂联合应用可通过以下途径克服黑色素瘤对ICI的耐药性 激活NK细胞、T效应细胞和干细胞样记忆T细胞。我们建议进行一系列的预审 临床研究(目标1)利用室内开发的与临床相关的黑色素瘤的新动物模型 突变决定DR-18与临床联合应用的应答和耐药机制 批准的ICIS(PD-1、CTLA-4和LAG-3的抑制剂)。我们已经改造了小鼠模型，使其能够 评估抗原特异性T细胞反应，以确定T效应和记忆功能是如何改善的。 鉴于肿瘤细胞中I类MHC丢失是人类对抗PD-1产生耐药性的主要原因，我们还将 研究DR-18单独和ICIS在B2M基因敲除模型(MHC-I缺陷)中的作用。在目标2中，我们将进行 ST-067联合免疫检查点抑制剂治疗进展期患者的I/II期临床试验 在之前的含有抗PD-1的方案中。参加试验的患者的肿瘤和血液样本将 使用尖端空间技术确定人类反应/抵抗的细胞机制 耶鲁大学开发了转录组学方法，结果将与在AIM收集的小鼠样本进行比较 1.如果成功，这些研究将仔细支持ST-067在患者亚群中ICIS的进一步发展 由免疫细胞特性定义。这种方法也可以应用于其他类型的抗PD-1患者 耐药肿瘤也是如此，这些研究可能产生深远的影响。

PROJECT 3: PROJECT SUMMARY Major changes have occurred in treatment of unresectable melanoma in the last decade in which immune-based therapies have dramatically enhanced overall survival. Unfortunately, almost half the melanoma patients do not respond to immune checkpoint inhibitors (ICI) upfront, and others develop recurrent or resistant disease over time. Immunotherapies that can stimulate immunity in ICI-resistant melanoma are still therefore urgently needed. To this end, cytokines have potent immunostimulatory activities that make them attractive candidates for use in combination with ICIs to overcome resistance. Interleukin 18 (IL-18) is particularly appealing, because the IL-18 receptor (IL-18R) is specifically upregulated in CD8 tumor infiltrating lymphocytes and is widely expressed on natural killer (NK) cells. However, clinical trials of recombinant IL-18 were unsuccessful, likely due to upregulation of the endogenous IL-18 receptor antagonist or IL-18 binding protein, IL-18BP, which inhibits the immunostimulatory effects of IL-18. The Ring lab therefore created an engineered version of IL-18 that is resistant to the IL-18BP but fully retains its ability to activate the IL-18R. A clinical grade “decoy resistant” IL-18 (DR18) has been developed and licensed to Simcha Therapeutics by Yale University (ST-067). ST-067 is currently being investigated in a first-in-human clinical trial as monotherapy. In pre-clinical models, DR18 synergizes with anti-PD-1. Furthermore, in murine models, DR-18 is highly effective in treating ICI-resistant MHC class I deficient tumors, consistent with the ability of IL-18 to also activate NK cells. We hypothesize that combining DR-18 with immune checkpoint inhibitors can overcome ICI resistance in melanoma via activation of NK cells, T effector cells and stem-like memory T cells. We propose to conduct a series of pre- clinical studies (Aim 1) utilizing novel animal models developed in house with clinically relevant melanoma mutations to determine the mechanism of response and resistance of the combination of DR-18 with clinically approved ICIs (inhibitors of PD-1, CTLA-4 and LAG-3). We have engineered the murine models to enable evaluation of antigen-specific T cell responses to determine how T effector and memory function is improved. Seeing that class I MHC loss in tumor cells is a major cause of resistance to anti-PD-1 in humans, we will also study effects of DR-18 alone and with ICIs in B2m knockout models (MHC-I deficient). In Aim 2 we will conduct a phase I/II clinical trial of ST-067 with immune checkpoint inhibitors in patients whose disease has progressed on a prior regimen containing anti-PD-1. Tumor and blood samples from patients enrolled in the trial will be interrogated to determine cellular mechanisms of response/resistance in humans using cutting-edge spatial transcriptomics methods developed at Yale, and results will be compared to the murine samples collected in Aim 1. If successful, these studies will support further development of ST-067 with ICIs in patient subsets carefully defined by immune cell characteristics. This approach can be applied to patients with other types of anti-PD-1 resistant tumors as well, and these studies have the potential for far-reaching implications.