Nan Lidi, Qin Yuting, Huang Xiao, Pan Mingzhu, Wang Xiaomu, Lv Yanqing, Sorensen Annette, Kang Xiaoqiang, Ling Hong, Zhang Juan
Antibody Engineering Laboratory, School of Life Science and Technology, China Pharmaceutical University, Nanjing 211100, China.
Nanjing Leads Biolabs Co., Ltd., Nanjing 210019, China.
Int J Mol Sci. 2025 Aug 5;26(15):7567. doi: 10.3390/ijms26157567.
Although PD-1/PD-L1 inhibitors have transformed cancer immunotherapy, a substantial proportion of patients derive no clinical benefit due to resistance driven by the tumour microenvironment (TME). Transforming growth factor-β (TGF-β) is a key immunosuppressive cytokine implicated in this resistance. Several bifunctional antibodies that co-target PD-1 and TGF-β signalling have entered clinical trials and shown encouraging efficacy, but the mechanistic basis of their synergy is not fully understood. Here, we engineered 015s, a bifunctional fusion antibody that simultaneously targets murine PD-1 and TGF-β and evaluated its antitumour efficacy and mechanistic impact in pre-clinical models. Antibody 015s exhibited high affinity, dual target binding, and the effective inhibition of PD-1 and TGF-β signalling. In vivo, 015s significantly suppressed tumour growth compared with anti-mPD-1 or TGF-β receptor II (TGF-βRII) monotherapy. When combined with the CD24-targeted ADC, 015s produced even greater antitumour activity and achieved complete tumour regression. Mechanistic studies demonstrated that 015s significantly reduced tumour cell migration and invasion, reversed epithelial-mesenchymal transition (EMT), decreased microvascular density, and attenuated collagen deposition within the TME. Antibody 015s also decreased bioactive TGF-β1 and increased intratumoural IFN-γ, creating a more immunostimulatory milieu. These findings support further development of PD-1/TGF-β bifunctional antibodies for cancers with high TGF-β activity or limited response to immune checkpoint blockade.
尽管PD-1/PD-L1抑制剂已经改变了癌症免疫治疗，但由于肿瘤微环境（TME）驱动的耐药性，相当一部分患者并未获得临床益处。转化生长因子-β（TGF-β）是与这种耐药性相关的关键免疫抑制细胞因子。几种共同靶向PD-1和TGF-β信号传导的双功能抗体已进入临床试验并显示出令人鼓舞的疗效，但其协同作用的机制基础尚未完全了解。在这里，我们构建了015s，一种同时靶向小鼠PD-1和TGF-β的双功能融合抗体，并在临床前模型中评估了其抗肿瘤疗效和机制影响。抗体015s表现出高亲和力、双靶点结合以及对PD-1和TGF-β信号传导的有效抑制。在体内，与抗小鼠PD-1或TGF-β受体II（TGF-βRII）单药治疗相比，015s显著抑制肿瘤生长。当与靶向CD24的ADC联合使用时，015s产生了更大的抗肿瘤活性并实现了肿瘤完全消退。机制研究表明，015s显著减少肿瘤细胞迁移和侵袭，逆转上皮-间质转化（EMT），降低微血管密度，并减弱TME内的胶原沉积。抗体015s还降低了生物活性TGF-β1并增加了肿瘤内IFN-γ，营造了一个更具免疫刺激作用的微环境。这些发现支持进一步开发针对具有高TGF-β活性或对免疫检查点阻断反应有限的癌症的PD-1/TGF-β双功能抗体。
