Department of Pediatrics, New York Medical College, Valhalla, New York, USA
Department of Pediatrics, New York Medical College, Valhalla, New York, USA.
J Immunother Cancer. 2020 Oct;8(2). doi: 10.1136/jitc-2020-001238.
The prognosis of patients with relapsed or progressive B cell (CD20) non-Hodgkin's lymphoma (B-NHL), including Burkitt lymphoma (BL), is dismal due to chemoradiotherapy resistance. Novel therapeutic strategies are urgently needed. N-820 is a fusion protein of N-803 (formerly known as ALT-803) to four single-chains of rituximab. This agent has tri-specific binding activity to CD20 and enhanced antibody-dependent cell-mediated cytotoxicity.
We investigated the anti-tumor combinatorial effects of N-820 with ex vivo expanded peripheral blood natural killer (exPBNK) cells against rituximab-sensitive and rituximab-resistant CD20 BL in vitro using cytoxicity assays and in vivo using human BL xenografted NOD/SCID/IL2rγnull (NSG) mice. We also investigated the cytokines/chemokines/growth factors released using ELISA and multiplex assay. Gene expression changes were examined using real-time PCR arrays.
N-820 significantly enhanced the expression of NK activating receptors (p<0.001) and the proliferation of exPBNK cells with enhanced Ki67 expression and Stat5 phosphorylation (p<0.001). N-820 significantly enhanced the secretion of cytokines, chemokines, and growth factors including GM-CSF, RANTES, MIP-1B (p<0.001) from exPBNK cells as compared with the combination of rituximab+N-803. Importantly, N-820 significantly enhanced in vitro cytotoxicity (p<0.001) of exPBNK with enhanced granzyme B and IFN-γ release (p<0.001) against BL. Gene expression profiles in exPBNK stimulated by N-820+Raji-2R showed enhanced transcription of , , , , and . Moreover, N-820 combined with exPBNK significantly inhibited rituximab-resistant BL growth (p<0.05) and extended the survival (p<0.05) of BL xenografted NSG mice.
Our results provide the rationale for the development of a clinical trial of N-820 alone or in combination with endogenous or ex vivo expanded NK cells in patients with CD20 B-NHL failing prior rituximab containing chemoimmunotherapy regimens.
由于对放化疗的耐药性，复发或进展的 B 细胞（CD20）非霍奇金淋巴瘤（B-NHL）患者，包括伯基特淋巴瘤（BL），预后较差。迫切需要新的治疗策略。N-820 是 N-803（以前称为 ALT-803）与四个利妥昔单抗单链的融合蛋白。该药物对 CD20 具有三特异性结合活性，并增强抗体依赖性细胞介导的细胞毒性。
我们通过细胞毒性测定在体外研究了 N-820 与体外扩增的外周血自然杀伤（exPBNK）细胞联合应用对利妥昔单抗敏感和利妥昔单抗耐药的 CD20 BL 的抗肿瘤组合效应，并使用人 BL 异种移植 NOD/SCID/IL2rγnull（NSG）小鼠进行体内研究。我们还使用 ELISA 和多重分析检测释放的细胞因子/趋化因子/生长因子。使用实时 PCR 阵列检查基因表达变化。
N-820 显著增强了 NK 激活受体的表达（p<0.001），并增强了 Ki67 表达和 Stat5 磷酸化的 exPBNK 细胞的增殖（p<0.001）。与利妥昔单抗+N-803 联合使用相比，N-820 显著增强了 exPBNK 细胞分泌细胞因子、趋化因子和生长因子，包括 GM-CSF、RANTES、MIP-1B（p<0.001）。重要的是，N-820 显著增强了 exPBNK 对 BL 的体外细胞毒性（p<0.001），并增强了颗粒酶 B 和 IFN-γ的释放（p<0.001）。N-820+Raji-2R 刺激的 exPBNK 的基因表达谱显示转录因子 、 、 、 、 和 的转录增强。此外，N-820 联合 exPBNK 显著抑制利妥昔单抗耐药 BL 的生长（p<0.05），并延长 BL 异种移植 NSG 小鼠的存活（p<0.05）。
我们的结果为 N-820 单独或与先前包含利妥昔单抗的化疗免疫治疗方案失败的 CD20 B-NHL 患者的内源性或体外扩增 NK 细胞联合应用的临床试验提供了依据。
