Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai, China.
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
Br J Pharmacol. 2021 Jul;178(13):2651-2670. doi: 10.1111/bph.15457. Epub 2021 May 4.
PD-1/PD-L1 antibodies have achieved great success in clinical treatment. However, monoclonal antibody drugs also have challenges, such as high manufacturing costs, poor diffusion, low oral bioavailability and limited penetration into tumour tissue. The development of small-molecule inhibitors of PD-1/PD-L1 interaction represents a promising perspective to overcome the above challenges in cancer immunotherapy.
We explored structural activity relationships and used biochemical assays to generate a lead compound (ZE132). CD8+ T-cells killing assay and Ifng expression assay were used to verify the in vitro cellular activity of ZE132. Off-target study was performed to verify the selectivity. Syngeneic mouse models were used to verify the in vivo activity of ZE132 in tumour immune microenvironment (TIME). We also performed pharmacokinetics profiling in mice and The Cancer Genome Atlas database analysis.
ZE132 can effectively inhibit the PD-1/PD-L1 interactions in vitro, and it has a potent affinity to PD-L1. ZE132 shows robust anti-tumour effects in vivo, better than anti-PD-1 antibody. In the analysis of TIME, we found that ZE132 treatment promotes cytotoxic T-cell tumour infiltration and induces IL-2 expression. In addition, ZE132 elicits strong inhibitory effects on the mRNA expression of TGF-β, which may serve as a potential biomarker to predict responsiveness to PD-1/PD-L1 immunotherapies.
We identified a new lead compound ZE132 targeting PD-1/PD-L1 interactions, not only showing favourable drug-like properties in vitro and in vivo but also showing the advantage of overcoming the barrier of TIME compared to anti-PD-1 antibody.
PD-1/PD-L1 抗体在临床治疗中取得了巨大成功。然而，单克隆抗体药物也存在挑战，如制造成本高、扩散性差、口服生物利用度低以及对肿瘤组织的穿透力有限。PD-1/PD-L1 相互作用的小分子抑制剂的开发代表了克服癌症免疫治疗中上述挑战的有前途的方法。
我们探索了结构-活性关系，并使用生化测定生成了先导化合物（ZE132）。CD8+T 细胞杀伤测定和 Ifng 表达测定用于验证 ZE132 的体外细胞活性。进行脱靶研究以验证选择性。使用同源小鼠模型验证 ZE132 在肿瘤免疫微环境（TIME）中的体内活性。我们还在小鼠中进行了药代动力学分析和癌症基因组图谱数据库分析。
ZE132 可有效抑制 PD-1/PD-L1 相互作用体外，对 PD-L1 具有很强的亲和力。ZE132 在体内具有强大的抗肿瘤作用，优于抗 PD-1 抗体。在 TIME 分析中，我们发现 ZE132 治疗可促进细胞毒性 T 细胞肿瘤浸润并诱导 IL-2 表达。此外，ZE132 对 TGF-β 的 mRNA 表达具有强烈的抑制作用，这可能作为预测对 PD-1/PD-L1 免疫治疗反应的潜在生物标志物。
我们鉴定了一种针对 PD-1/PD-L1 相互作用的新型先导化合物 ZE132，不仅在体外和体内具有良好的药物特性，而且与抗 PD-1 抗体相比，还具有克服 TIME 障碍的优势。
