Neoadjuvant immunotherapy approaches to early stage melanoma

项目摘要-项目3 提高高危II期黑色素瘤患者的存活率是一个尚未得到满足的需求。目前， 尽管复发率和死亡率高得令人无法接受，但II期黑色素瘤的治疗仍在监测中 仅通过手术观察。前哨淋巴结(SLN)是第一个被原发肿瘤引流的淋巴结。 它不仅是癌细胞转移的靶点，也是肿瘤抗原的免疫传感器。 由原发皮肤黑色素瘤释放。引流型淋巴转移模型的初步数据 在黑色素瘤转移到LN之前和期间，髓系细胞数量显著增加。我们 提出LN的这些变化可能会损害它作为预防黑色素瘤的守门人的能力 通过淋巴管传播；(Ii)作为抗原特异性T细胞免疫的指导者，能够控制局部 疾病和对血行播散的干预。因此，我们的总体假设是， 防止局部和远处黑色素瘤扩散的SLN依赖于其免疫健康， 它是柔韧的，并由淋巴结居留髓系的免疫刺激能力决定 细胞。在目标1中，Karakousis博士(临床共同项目负责人(PL))和Schuchter博士(共同研究员(I))将进行 一项由研究者发起的新辅助剂培溴利珠单抗治疗IIB/C期黑色素瘤的第二阶段临床试验。 使用来自这项临床试验和分期匹配的历史队列的原发肿瘤和前哨淋巴结(SLN)， 我们将确定免疫治疗对人肝癌细胞免疫表型和抗转移能力的影响。 SLN。我们将使用由Wherry博士(co-I)首创的无偏见的全球侧写策略和 由我们的发现指导的假设驱动的方法，研究巨噬细胞在准备转移瘤中的作用 NICE(Beatty，Applied co-PL)确定SLN阳性和阴性患者的治疗相关变化。 对同基因模型的研究将揭示髓系细胞亚群在引导LN生物学变化中的作用 由黑色素瘤的发展及其对抗PD1治疗的影响引发。目标2将检验这一假设 淋巴结树突状细胞的免疫刺激能力决定了对抗PD1抗体应答的可能性 心理治疗。在Herlyn博士和Beatty博士的共同领导下，我们将使用基于组织和细胞的复合 分析从我们的第二阶段试验和阶段配对的历史对照中收集的样本的分析方法，目标是 明确T细胞与髓系细胞(包括树突状细胞)的相互作用及其对治疗反应的影响 和临床结果。此外，我们将确定临床上可用的TLR激动剂是否可以增强 引流性LN的免疫刺激能力，并在这样做的同时，提高抗PD-1治疗的疗效 用患者来源的异种移植物挑战人源化小鼠，这种异种移植物高保真地模拟早期黑色素瘤。 影响：我们预计新辅助免疫治疗将大幅降低SLN阳性率，这是有保证的未来 旨在改变临床实践的随机研究。我们希望将SLN确定为一项重要的 黑色素瘤发病机制的决定因素和免疫治疗的临床结果。

Project Summary – Project 3 There is an unmet need to improve the survival of patients with high-risk Stage II melanoma. Currently, the treatment for Stage II melanoma is surveillance despite unacceptably high recurrence and mortality rates observed with surgery alone. The sentinel lymph node (SLN) is the first lymph node drained by a primary tumor and is not only a target for metastasizing cancer cells but also an immunological sensor of tumor antigens released by primary cutaneous melanoma. Our preliminary data in a draining lymph node (LN) metastasis model shows striking increases in myeloid cell populations prior to and during melanoma metastasis to the LN. We propose that these changes in the LN may compromise its ability to act (i) as a gatekeeper to prevent melanoma spread via the lymphatics and (ii) as an instructor of antigen-specific T cell immunity capable of controlling local disease and intervening on hematogenous spread. Thus, our overall hypothesis is that the capacity of the SLN to protect against locoregional and distant melanoma spread is dependent on its immune health, which is pliable and determined by the immunostimulatory capacity of lymph node-resident myeloid cells. In Aim 1, Drs. Karakousis (Clinical co-Project Leader (PL)) and Schuchter (co-Investigator (I)) will conduct an investigator-initiated Phase II clinical trial of neoadjuvant pembrolizumab in clinical Stage IIB/C melanoma. Using primary tumors and sentinel LNs (SLN) from both this clinical trial and stage-matched historical cohorts, we will determine the effects of immunotherapy on the immunophenotype and anti-metastatic capacity of the SLN. We will use a combination of unbiased global profiling strategies pioneered by Dr. Wherry (co-I) and hypothesis-driven approaches guided by our discoveries into the role of macrophages in preparing the metastatic niche (Beatty, Applied co-PL) to determine therapy-associated changes in SLN-positive and -negative patients. Studies in syngeneic models will then inform the role of myeloid cell subsets in directing changes in LN biology triggered by melanoma development and their impact on anti-PD1 therapy. Aim 2 will test the hypothesis that the immunostimulatory capacity of lymph node dendritic cells determines the likelihood of response to anti-PD1 therapy. Under the leadership of co-PLs Drs. Herlyn and Beatty , we will use multiplex tissue- and cell-based assays to analyze samples collected from our Phase II trial and stage-matched historical controls with the goal to define T cell interactions with myeloid cells, including dendritic cells, and their impact on treatment response and clinical outcomes. In addition, we will determine if clinically-available TLR agonists can enhance the immunostimulatory capacity of the draining LN and in doing so, improve the efficacy of anti-PD-1 therapy using humanized mice challenged with patient-derived xenografts which model early stage melanoma with high fidelity. Impact: We anticipate neoadjuvant immunotherapy will substantially reduce SLN positivity rates warranting future randomized studies designed to change clinical practice. We expect to identify the SLN as an important determinant of melanoma pathogenesis and clinical outcomes to immunotherapy.