Purpose:Half of the patients with high-risk neuroblastoma who receive GD2-targeted mAb do not achieve long-term remissions. Recently, the antibody hu14.18 has been linked to IL2 (hu14.18-IL2) to enhance its efficacy and shown promising preclinical and clinical activity. We developed two new immunocytokines (IC) by linking two other γc cytokines, IL15 and IL21, to hu14.18. The purpose of this study was to compare hu14.18-IL15 and -IL21 with hu14.18-IL2 in their ability to induce antibody-dependent cell-mediated cytotoxicity (ADCC) against neuroblastoma.Experimental Design:We assessed ADCC of hu14.18-IL15 and -IL2 (human cytokines, cross-reactive to mouse) against GD2low and GD2high neuroblastoma cell lines in vitro. T-cell–deficient mice with orthotopic patient-derived xenografts (PDX) and immunocompetent mice with transplantable orthotopic neuroblastoma were used to test all three ICs, including hu14.18-IL21 (murine IL21, not cross-reactive to human). Mechanistic studies were performed using single-cell RNA-sequencing (scRNA-seq).Results:hu14.18-IL15 and hu14.18-IL2 mediated equivalent in vitro ADCC by human NK cells. When combined with chemotherapy, all three ICs similarly controlled the growth of PDXs in nude mice with murine NK effector cells. However, hu14.18-IL15 and -IL21 outperformed hu14.18-IL2 in immunocompetent mice with syngeneic neuroblastoma, inducing complete tumor regressions and extending survival. scRNA-seq data revealed an increase in CD8+ T cells and M1 tumor-associated macrophages and decreased regulatory T cells and myeloid-derived suppressor cells in the tumor microenvironment.Conclusions:Hu14.18-IL15 and Hu14.18-IL21 exhibit robust preclinical activity, warranting further consideration for clinical testing in patients with GD2-expressing neuroblastoma.

中文翻译：

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与 IL15 和 IL21 缀合的抗 GD2 抗体介导针对神经母细胞瘤的有效抗肿瘤细胞毒性

目的：接受 GD2 靶向单克隆抗体治疗的高危神经母细胞瘤患者中有一半未获得长期缓解。最近，抗体hu14.18已与IL2（hu14.18-IL2）连接以增强其功效，并显示出有希望的临床前和临床活性。我们通过将另外两种 γc 细胞因子 IL15 和 IL21 与 hu14.18 连接，开发了两种新的免疫细胞因子 (IC)。本研究的目的是比较 hu14.18-IL15 和 -IL21 与 hu14.18-IL2 诱导针对神经母细胞瘤的抗体依赖性细胞介导的细胞毒性 (ADCC) 的能力。 实验设计：我们评估了 hu14.18 的 ADCC -IL15 和 -IL2（人类细胞因子，与小鼠有交叉反应）在体外针对 GD2low 和 GD2high 神经母细胞瘤细胞系。使用具有原位患者来源异种移植物 (PDX) 的 T 细胞缺陷小鼠和具有可移植原位神经母细胞瘤的免疫活性小鼠来测试所有三种 IC，包括 hu14.18-IL21（鼠 IL21，与人类无交叉反应）。使用单细胞 RNA 测序 (scRNA-seq) 进行机制研究。结果：hu14.18-IL15 和 hu14.18-IL2 通过人 NK 细胞介导等效的体外 ADCC。当与化疗联合使用时，所有三种 IC 均类似地控制了具有鼠 NK 效应细胞的裸鼠中 PDX 的生长。然而，在具有同基因神经母细胞瘤的免疫功能正常小鼠中，hu14.18-IL15 和 -IL21 的表现优于 hu14.18-IL2，可诱导肿瘤完全消退并延长生存期。