PO.TB05.01 · 肿瘤生物学
利用人源类器官临床前平台评估靶向GD2的抗体偶联药物治疗DIPG
Evaluating GD2-targeting antibody-drug conjugates for DIPG using human organoid-based preclinical platforms
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
弥漫性内生型脑桥胶质瘤（DIPG）是一种普遍致命的儿童脑肿瘤，中位生存期不足12个月。尽管近期FDA对ONC201的加速批准为DIPG/DMG群体带来了期待已久的进展感，但核心治疗难题仍远未解决。DIPG中频繁存在的H3K27M突变与GD2（一种临床上可靶向的表面抗原）的表达升高相关。靶向GD2的CAR-T疗法在DIPG中已显示出令人鼓舞的早期活性。然而，抗原异质性、固有的生产周期以及神经毒性风险等挑战依然存在。抗体偶联药物（ADC）提供了一种更可控的、现成可用的治疗方法，可能克服这些局限，但其在DIPG中的潜力仍未被探索。为评估靶向GD2的ADC的疗效、耐药性和安全性，我们采用了两个互补的人源类器官平台。首先，使用NanoGlio（一种高通量纳升级液滴3D类器官系统）构建DIPG模型。其次，我们建立了DIPG NanoGlio与iPSC来源脑类器官的共培养模型以评估神经毒性。我们成功构建了来源于9个DIPG模型的NanoGlio，这些模型反映了DIPG中通常鉴定出的关键遗传学改变，包括H3.3（H3F3A）或H3.1（HIST1H3B）突变。我们通过流式细胞术和3D荧光抗体细胞追踪（3D-FACT）评估了GD2的表达，观察到不同DIPG模型间GD2表达差异极大。我们在这些模型中测试了M3554，这是一种首创的处于临床阶段的抗GD2 ADC，其偶联了拓扑异构酶I抑制剂exatecan。M3554在DIPG NanoGlio中表现出强效的细胞毒性。使用其未偶联的载荷Exatecan进行耐药性分析显示，ADC反应降低主要由内在的载荷耐药性驱动，而非低GD2表达。GD2表达极低的DIPG模型（包括SF7761和SU-DIPG-IV）对M3554也有强烈反应，这与旁观者杀伤效应一致。iPSC来源的脑类器官（GD2阴性）在M3554作用下表现出极小的毒性，而等剂量的Exatecan则诱导了广泛的细胞死亡。未来的工作将通过共封装GD2+和GD2- DIPG细胞系统性评估GD2 ADC的旁观者效应，并使用我们的DIPG-脑共培养模型评估M3554的疗效和神经毒性。本研究的成功完成将为评估和使用靶向GD2的ADC治疗DIPG提供关键的临床前证据。
查看英文原文 English abstract
Diffuse intrinsic pontine glioma (DIPG) is a universally fatal pediatric brain tumor with a median survival of less than 12 months. Although the recent FDA accelerated approval of ONC201 offers a long-awaited sense of progress for the DIPG/DMG community, the central therapeutic problem remains far from solved. The frequent presence of H3K27M mutations in DIPG is associated with elevated expression of GD2, a clinically actionable surface antigen. GD2-directed CAR-T therapies have shown encouraging early activity in DIPG. However, challenges such as antigen heterogeneity, inherent manufacturing lead time, and risks of neurotoxicity remain. Antibody-drug conjugates (ADCs) offer a more controllable, off-the-shelf therapeutic approach that could overcome these limitations, yet their potential in DIPG remains unexplored. To evaluate the efficacy, resistance, and safety of GD2-targeting ADCs, we employed two complementary human-derived organoid platforms. First, DIPG models were generated using NanoGlio, a high-throughput nanoliter-volume droplet 3D organoid system. Second, we established a co-culture model with DIPG NanoGlio and iPSC-derived brain organoids to assess neurotoxicity. We successfully generated NanoGlio derived from 9 DIPG models reflecting the key genetic alterations typically identified in DIPG, including mutations in H3.3 (H3F3A) or H3.1 (HIST1H3B). We assessed the expression of GD2 by flow cytometry and 3D-Fluorescence Antibody Cell Tracking (3D-FACT) and observed widely variable GD2 expression across DIPG models. We tested M3554, a first-in-class clinical-stage anti-GD2 ADC conjugated to exatecan, a topoisomerase I inhibitor, in these models. M3554 exhibited potent cytotoxicity across DIPG NanoGlios. Resistance profiling using its unconjugated payload, Exatecan, revealed that reduced ADC response was primarily driven by intrinsic payload resistance rather than low GD2 expression. DIPG models with very low GD2 expression, including SF7761 and SU-DIPG-IV, also responded strongly to M3554, consistent with a bystander killing effect. iPSC-derived brain organoids (GD2-negative) showed minimal toxicity with M3554, whereas equivalent doses of Exatecan induced extensive cell death. Future work will systematically evaluate GD2 ADC bystander effect via co-encapsulation of GD2+ and GD2- DIPG cells, and assess the efficacy and neurotoxicity of M3554 using our DIPG-brain co-culture model. Successful completion of this study will provide critical preclinical evidence supporting the assessment and use of GD2-targeting ADCs in DIPG treatment.
利益披露 Disclosure
Z. Wang, None..
E. Miller, None..
W. Huang, None..
S. Kawakita, None..
L. Vanderpool, None..
F. Bustamante, None..
U. Kim, None..
Z. Wang, None.