PO.IM01.15 · 免疫学
AR170：一种新型 PD-1xVEGFxIL-2v 三特异性免疫细胞因子，重新定义下一代癌症免疫治疗
AR170, a novel PD-1xVEGFxIL-2v tri-specific immunocytokine to redefine next generation cancer immunotherapy
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景
同时靶向 PD-1 和 VEGF 的双特异性抗体在延长单独 PD-1 抑制的疗效方面显示出前景，然而尽管治疗应答改善且无进展生存期延长，与抗 PD-1 单药相比在总生存方面的优势迄今仍有限。联合白细胞介素-2（IL-2）可显著增强 PD-1xVEGF 双特异性抗体的疗效，但由于全身毒性仍存在挑战。为克服这一局限，AR170 被设计为一种新型三特异性免疫细胞因子，通过整合优化的顺式（cis）作用 IL-2 变体（IL-2v）和完全的 Fc 沉默，同时结合 PD-1、VEGF 和 IL-2 受体。
方法
通过 SE-HPLC 评估 VEGF 诱导的 AR170 二聚化。使用生物膜层干涉技术（BLI）和流式细胞术确认二聚化后 PD-1 结合增强。使用荧光素酶报告基因试验验证对 PD-1/PD-L1 和 VEGF/VEGFR 相互作用的阻断。开展功能试验，通过流式细胞术或 ELISA 测量 T 细胞的活化、增殖、细胞毒性和细胞因子分泌。通过 ADCC、ADCP 和 CDC 试验确认 Fc 沉默。在 hPBMC 移植和 hPD-1/hPD-L1/hVEGF 三敲入小鼠模型中评估抗肿瘤疗效。在 hIL-2R 敲入小鼠和食蟹猴中开展安全性和药代动力学研究。
结果
AR170 发生 VEGF 诱导的二聚化，协同增强对 PD-1 和 VEGF 两者的阻断活性。AR170 递送 PD-1 依赖性的顺式（cis）作用 IL-2v 信号。此外，Fc 沉默技术有效地最小化了 Fc 介导的效应功能。在 VEGF 富集的耗竭条件下，与 PD-1 抑制剂或 PD-1xVEGF 双特异性抗体相比，AR170 在体外诱导了强劲的 CD8+ T 细胞增殖和活化。在表达 VEGF 的荷瘤（≥300 mm³）人源化小鼠模型中，AR170 引发的抗肿瘤应答快速而持久，优于 PD-1 抑制剂或 PD-1xVEGF 双特异性抗体，而清除 CD8+ T 细胞则消除了抗肿瘤疗效。免疫细胞分析显示 AR170 治疗后 TCF1⁺PD-1⁺CD8⁺ T 细胞比例升高。AR170 在小鼠和食蟹猴中均表现出良好的安全性和药代动力学特征。
结论
AR170 是一种下一代癌症免疫治疗药物，采用新型 IL-2v 融合策略，超越了 PD-1xVEGF 双特异性抗体的疗效局限。
查看英文原文 English abstract
Background
Bispecific antibodies that simultaneously target PD-1 and VEGF have shown promise in extending the efficacy of PD-1 inhibition alone, yet despite improved treatment response and prolonged progression-free survival, overall survival advantage over anti-PD-1 monotherapy is so far limited. Interleukin-2 (IL-2) combination can markedly potentiate the efficacy of PD-1xVEGF bispecific antibodies, but challenges remain due to systemic toxicity. To overcome this limitation, AR170 was designed as a novel tri-specific immunocytokine that simultaneously engages PD-1, VEGF, and the IL-2 receptor by incorporating an optimized cis -acting IL-2 variant (IL-2v) and complete Fc-silencing.
Methods
VEGF-induced AR170 dimerization was assessed by SE-HPLC. Enhanced PD-1 binding after dimerization was confirmed using bio-layer interferometry (BLI) and flow cytometry. Blockade of PD-1/PD-L1 and VEGF/VEGFR interactions was validated using a luciferase reporter assay. Functional assays were conducted to measure T cell activation, proliferation, cytotoxicity, and cytokine secretion by flow cytometry or ELISA. Fc-silencing was confirmed by ADCC, ADCP, and CDC assays. Antitumor efficacy was evaluated in both hPBMC-engrafted and hPD-1/hPD-L1/hVEGF triple knocked-in mouse models. Safety and pharmacokinetic studies were carried out in hIL-2R knock-in mice and cynomolgus monkeys.
Results
AR170 undergoes VEGF-induced dimerization that synergizes blockade activity of both PD-1 and VEGF. AR170 delivers PD-1-dependent cis -acting IL-2v signaling. In addition, Fc-silencing technology effectively minimizes Fc-mediated effector function. AR170 under VEGF-enriched exhaustion conditions induced robust proliferation and activation of CD8 + T cells compared to either PD-1 inhibitor or PD-1xVEGF bispecific antibody in vitro . AR170 elicited rapid and durable antitumor responses superior to either PD-1 inhibitor or PD-1xVEGF bispecific antibody in VEGF-expressing tumor-bearing (≥300 mm³) humanized mouse models, while depletion of CD8 + T cells eliminated antitumor efficacy. Immune cell profiling showed elevated proportion of TCF1⁺PD-1⁺CD8⁺ T cells following AR170 treatment. AR170 demonstrated favorable safety and pharmacokinetic profiles in both mice and cynomolgus monkeys.
Conclusions
AR170 is a next-generation cancer immunotherapy that uses a novel IL-2v fusion approach to surpass the efficacy limitations of PD-1xVEGF bispecific antibodies.
利益披露 Disclosure
S. Yu, None..
J. Song, None..
J. Yoon, None..
W. Jang, None..
Y. Park, None..
C. Rhee, None..
J. Yoon, None..
D. Kim, None..
W. Park, None..
Y. Kim, None.