Project 2: Immunotherapy with CMP-001 intratumoral and nivolumab in melanoma

项目摘要：项目2 使用抗PD1单抗(MAbs)的免疫治疗与改善反应和 包括黑色素瘤在内的多发性实体瘤的存活率。抗PD1单抗(抗PD1)产生持久的 33-40%的黑色素瘤患者的临床反应，毒性最小。而双抗PD1/抗CTLA4 封锁可产生更高的应答率(58%)和5年PFS(36%)，这与55%的3/4级相关 不良事件。因此，迫切需要新的组合免疫疗法来提高机体的免疫功能。 在减轻晚期黑色素瘤严重不良事件发生率的同时，抗PD1的疗效。一大专业 限制抗PD1疗效的障碍是缺乏自发的肿瘤浸润性T细胞(TIL)和缺陷 在所谓的“冷”或非炎性肿瘤中，肿瘤微环境(TME)中产生IFNA。一件有希望的事 克服这一障碍的治疗方法是通过Toll样受体9(TLR9)激动剂。TLR9主要是 由浆细胞样树突状细胞(PDCs)和B细胞表达，并与包括未甲基化的激动剂结合 胞苷鸟苷寡核苷酸(CpG)。我们最近进行了第一次人体试验 新型A型CpG瘤内新辅助化学发光蛋白和尼伏卢单抗在PD1单纯高危切除中的应用 黑色素瘤(NCT03618641)。在30名可评估的黑色素瘤患者中，我们观察到60%的主要病理变化。 注射肿瘤中CD8+TIL和瘤周CD303+pDC增加的应答，且频率更高 应答者外周血中的PD1+Ki67+CD8+T细胞肿瘤内注射化学发光蛋白联合尼伏卢单抗治疗 (CMP/Nivolumab)对PD1难治性黑色素瘤也显示出临床疗效，在未注射的情况下有反应 肿瘤，支持发生全身抗肿瘤免疫以外的注射肿瘤。为了进一步发展我们的 了解注射和非注射对CMP/Nivolumab的反应或耐药机制 肿瘤，我们将利用随机II/III期包括的60名黑色素瘤患者的子研究 可及性治疗PD1幼稚转移性黑色素瘤的临床试验 肿瘤为肿瘤内慢性粒细胞增多症。根据我们的初步发现，我们将调查CMP/Nivolumab ：1)增加PDC的活化和在注射肿瘤中的募集，以促进CD8+TIL的扩张和功能 在注射和未注射的肿瘤中；2)诱导黑色素瘤细胞死亡，启动强大的新表位特异性CD8+T细胞 注射肿瘤中的细胞，以及向黑色素瘤相关抗原扩散的表位；以及3)未能诱导有效 T细胞反应由黑色素瘤细胞-外在或黑色素瘤细胞-内在机制决定。总体而言， 这一应用中的发现将提高我们对该病毒的反应和抗性机制的理解。 CMP/Nivolumab在黑色素瘤中的作用他们将进一步支持新的组合免疫疗法，以进一步 增强环磷酰胺/尼伏卢单抗对荷瘤裸鼠的免疫原性和临床活性 晚期黑色素瘤。

PROJECT SUMMARY ABSTRACT: Project 2 Immunotherapy with anti-PD1 monoclonal antibodies (mAbs) is associated with improved response and survival rates in multiple solid tumors, including melanoma1. Anti-PD1 mAbs (anti-PD1) produces durable clinical responses in 33-40% of melanoma patients with minimal toxicity. While dual anti-PD1/anti-CTLA4 blockade produces higher response rates (58%) and 5-year PFS (36%), this is associated with 55% grade 3/4 adverse events. Therefore, there is a critical need for novel combinatorial immunotherapy to improve the efficacy of anti-PD1 while mitigating the rate of serious adverse events in advanced melanoma. One major barrier limiting the efficacy of anti-PD1 is the lack of spontaneous tumor-infiltrating T cells (TILs) and defective IFNa production in tumor microenvironment (TME) in so-called “cold” or non-inflamed tumors. One promising therapeutic approach to overcome this hurdle is via toll-like receptor 9 (TLR9) agonists. TLR9 is predominantly expressed by plasmacytoid dendritic cells (pDCs) and B cells and binds to agonists including unmethylated cytosine guanosine oligodinucleotides (CpG). We have recently performed the first-in-human trial of neoadjuvant intratumoral CMP, a novel type A CpG, and Nivolumab in PD1-naïve high-risk resectable melanoma (NCT03618641). In 30 evaluable melanoma patients, we have observed 60% major pathologic responses with increased CD8+ TILs and peritumoral CD303+ pDCs in injected tumors, and higher frequency circulating PD1+Ki67+CD8+ T cells in responders. Therapy with intratumoral CMP and Nivolumab (CMP/Nivolumab) has also shown clinical efficacy in PD1 refractory melanoma with responses in non-injected tumors, supporting the occurrence of systemic antitumor immunity beyond the injected tumors. To further our understanding of the mechanisms of responses or resistance to CMP/Nivolumab in injected and non-injected tumors, we will take advantage of a substudy of 60 melanoma patients included in the randomized phase II/III clinical trial evaluating CMP/nivolumab vs. nivolumab in PD1 naïve metastatic melanoma with accessible tumors for intratumoral CMP. Based on our preliminary findings, we will investigate whether CMP/Nivolumab :1) increases pDC activation and recruitment into injected tumors to promote CD8+TIL expansion and functions in injected and non-injected tumors; 2) induces melanoma cell death, primes potent neoepitope-specific CD8+T cells in injected tumors, and epitope spreading to melanoma-associated antigens; and 3) fails to induce potent T cell responses because of melanoma cell-extrinsic or melanoma cell-intrinsic mechanisms. Collectively, the findings in this application will improve our understanding of the mechanisms of response and resistance to CMP/Nivolumab in melanoma. They will further support novel combinatorial immunotherapies to further enhance the immunogenicity and clinical activity of CMP/Nivolumab in injected and non-injected tumors of advanced melanoma.