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

项目摘要：项目2 使用抗PD 1单克隆抗体（mAb）的免疫治疗与改善的应答相关， 包括黑色素瘤在内的多种实体瘤的生存率1。抗PD 1 mAb（抗PD 1）可产生持久的 在33-40%的黑素瘤患者中具有最小毒性的临床反应。而双重抗PD 1/抗CTLA 4 阻断产生更高的缓解率（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改善免疫应答。 抗PD 1的有效性，同时降低晚期黑色素瘤中严重不良事件的发生率。一个主要 限制抗PD 1效力的屏障是缺乏自发性肿瘤浸润性T细胞（TIL）和缺陷性T细胞（TIL）。 在所谓的“冷”或非发炎肿瘤中肿瘤微环境（TME）中的IFNa产生。一个有希望 克服这一障碍的治疗方法是通过Toll样受体9（TLR 9）激动剂。TLR 9主要 由浆细胞样树突状细胞（pDC）和B细胞表达，并结合激动剂，包括未甲基化的 胞嘧啶鸟苷寡核苷酸（CpG）。我们最近进行了首次人体试验， 新辅助肿瘤内CMP（一种新型A型CpG）和Nivolumab治疗PD 1初治高危可切除患者 黑色素瘤（NCT 03618641）。在30例可评估的黑色素瘤患者中，我们观察到60%的主要病理性 在注射的肿瘤中具有增加的CD 8 + TIL和肿瘤周围的CD 303 + pDC的应答，以及更高的频率 应答者中的循环PD 1 + Ki 67 + CD 8 + T细胞。肿瘤内CMP和Nivolumab治疗 (CMP/纳武单抗）也显示出在PD 1难治性黑色素瘤中的临床疗效， 肿瘤，支持在注射的肿瘤之外发生全身抗肿瘤免疫。推进我们 了解注射和非注射中对CMP/Nivolumab的应答或耐药性机制 肿瘤，我们将利用60例黑色素瘤患者的子研究，包括在随机II/III期 评估CMP/nivolumab与nivolumab治疗PD 1初治转移性黑色素瘤的临床试验， 肿瘤内CMP。根据我们的初步发现，我们将研究CMP/Nivolumab是否 1）增加pDC活化和募集到注射的肿瘤中以促进CD 8 +TIL扩增和功能 2）诱导黑色素瘤细胞死亡，引发有效的新表位特异性CD 8 +T细胞 注射肿瘤中的细胞，以及表位扩散到黑素瘤相关抗原;以及3）未能诱导有效的 由于黑色素瘤细胞外在或黑色素瘤细胞内在机制引起的T细胞应答。统称 这项应用的发现将提高我们对免疫应答和抵抗机制的理解。 CMP/Nivolumab治疗黑素瘤。他们将进一步支持新的组合免疫疗法， 增强CMP/Nivolumab在注射和非注射肿瘤中的免疫原性和临床活性， 晚期黑素瘤

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.