Radiation and dendritic cells to hepatomas to improve immunotherapy response

摘要/摘要 肝细胞癌(肝细胞癌)是最常见的原发性肝癌，其存活率低。 患有无法切除的疾病的患者。PD-L1抑制剂阿特唑单抗(ATEZO)和血管内皮生长因子最近获批 抑制剂贝伐单抗(Bev)在一线治疗中是一个里程碑式的进步；然而，进一步的改善是 中位无进展生存期不到7个月。我们已经通过一个多中心找到了 肿瘤转录组高表达干扰素-γ和MHC-II信号(INFAP)的合作研究 签名)与对PD-1抑制剂的反应增加和存活率增加有关。我们建议增加大剂量 体外放射治疗(EBRT)后肿瘤内注射自体树突状细胞(DC) Tatezo/Bev可进一步增强免疫刺激作用。辐射可诱导炎性肿瘤细胞 有利于肿瘤新抗原呈递的死亡。EBRT后注射自体DC将 是一种促进体内肿瘤抗原摄取和提呈以扩大肿瘤反应性的新方法 细胞毒T细胞。我们治疗过不能切除的肝肿瘤(肝细胞癌和胆管细胞癌)。 这种EBRT和DC方案的初步研究，有希望的反应和可接受的毒性(无≥3级 毒性)。五名受试者中有三名有部分反应，包括一名持续反应超过1 年。新的TCR克隆的出现和现有TCR克隆的扩展，包括带有肿瘤的克隆 已经观察到了反应性和细胞毒性特征，表明这种组合可以增强肿瘤的反应性。 细胞毒性T细胞反应。然而，许多TCR克隆也具有早期耗尽信号 多个检查点受体上调。因此，将直流注入与ATEZO/BEV相结合可能会进一步帮助 增强这些TCR克隆的细胞毒功能。我们假设将EBRT与 肿瘤内注射阿替唑单抗和贝伐单抗可改善慢性粒细胞白血病患者的PFS 这种作用是通过肿瘤反应性T细胞库的全身性扩增来实现的。 我们将通过两个目标来检验这一假设。1)评估这种联合疗法在一种 安全磨合阶段的第二阶段研究。1年内增加的PFS比率将是主要终点。2) 确定这种新的联合免疫疗法对肿瘤反应性T细胞谱系的影响。我们会 用scRNAseq和TCRseq鉴定TCR克隆的扩增和转录组图谱 血液和肿瘤，重点是肿瘤反应性TCR克隆。我们还将使用scRNAseq和Flow来分析 肿瘤和血液中其他免疫细胞的变化，重点是表达的变化 INFAP签名。最后，我们将使用成像细胞术来检查肿瘤与免疫空间的关系 在肿瘤里。我们的研究不仅将确定这种新的联合疗法的临床活性，还将使用 最先进的技术，以提高我们对这种免疫疗法的作用机制的了解。

Summary/Abstract Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer with dismal survival for patients with unresectable disease. Recent approval for PD-L1 inhibitor atezolizumab (atezo) and VEGF inhibitor bevacizumab (bev) in frontline treatment is a landmark advance; however further improvement is needed with a median progression free survival of less than 7 months. We have found through a multi-center cooperative study that tumor transcriptome signature high in interferon-gamma and MHC-II signaling (INFAP signature) is correlated with increased response and survival to PD-1 inhibitor. We propose to add high dose external beam radiotherapy (EBRT) followed by intra-tumor injection of autologous dendritic cells (DC) to atezo/bev to further enhance the immune stimulatory effect. Radiation can induce inflammatory tumor cell death that can be favorable for tumor neoantigen presentation. Injection of autologous DC after EBRT would be a novel method of boosting in vivo tumor antigen uptake and presentation to expand tumor-reactive cytotoxic T cells. We have treated subjects with unresectable liver tumors (HCC and cholangiocarcinoma) in a pilot study with this EBRT and DC approach with promising response and acceptable toxicity (no grade ≥3 toxicity). Three of the five subjects had partial response, including a patient with ongoing response beyond 1 year. Both emergence of new TCR clones and expansion of existing TCR clones, including clones with tumor reactive and cytotoxic profile, have been observed, suggesting this combination could enhance tumor reactive cytotoxic T cell response. However, many of the TCR clones also have early exhaustion signal with upregulation of multiple checkpoint receptors. Thus, combining DC injection with atezo/bev may help further enhance the cytotoxic functions of these TCR clones. We hypothesize that combining EBRT followed by intratumor DC injections with atezolizumab and bevacizumab can improve the PFS for patients with unresectable HCC and that the effect is mediated by systemic expansion of a tumor reactive T cell repertoire. We will test the hypothesis through 2 aims. 1) Assess the clinical efficacy of this combination therapy in a phase II study with a safety run-in phase. Increased PFS rate at 1 year will be the primary endpoint. 2) identify the effect of this novel combination immunotherapy on tumor reactive T cell repertoire. We will use scRNAseq and TCRseq to identify TCR clonal expansion and transcriptome profile of the TCR clones in the blood and tumor, with a focus on tumor reactive TCR clones. We will also use scRNAseq and flow to profile the changes of other immune cells in the tumor and blood, with a focus on the changes in expression of the INFAP signature. Finally, we will use imaging cytometry to examine the tumor and immune spatial relationship in the tumor. Our study will not only identify the clinical activities of this novel combination therapy but also use state-of-the-art technology to improve our understanding on the mechanism of action to this immunotherapy.