Discovery of Novel Small-Molecule-Based Potential PD-L1/EGFR Dual Inhibitors with High Druggability for Glioblastoma Immunotherapy
Zichao Yang, Ziqing Liu, Shanhe Wan, Jianwei Xu, Yaqi Huang, Haiqi He, Ting Liu, Ling Li, Yichang Ren, Jiajie Zhang, Jianjun Chen
Abstract
Based on the close relationship between programmed death protein ligand 1 (PD-L1) and epidermal growth factor receptor (EGFR) in glioblastoma (GBM), we designed and synthesized a series of small molecules as potential dual inhibitors of EGFR and PD-L1. Among them, compound EP26 exhibited the highest inhibitory activity against EGFR (IC 50 = 37.5 nM) and PD-1/PD-L1 interaction (IC 50 = 1.77 μM). In addition, EP26 displayed superior in vitro antiproliferative activities and in vitro immunomodulatory effects by promoting U87MG cell death in a U87MG/Jurkat cell coculture model. Furthermore, EP26 possessed favorable pharmacokinetic properties ( F = 22%) and inhibited tumor growth (TGI = 92.0%) in a GBM mouse model more effectively than Gefitinib (77.2%) and NP19 (82.8%). Moreover, EP26 increased CD4 + cells and CD8 + cells in tumor microenvironment. Collectively, these results suggest that EP26 represents the first small-molecule-based PD-L1/EGFR dual inhibitor deserving further investigation as an immunomodulating agent for cancer treatment.