Discovery of Noncovalent Diaminopyrimidine-based Inhibitors for Glioblastoma via a Dual FAK/DNA Targeting Strategy

Temozolomide, a widely used alkylating agent for glioblastoma treatment, faces significant challenges due to the development of resistance, which severely impacts patient survival. This underscores the urgent need for novel strategies to overcome this barrier. Focal adhesion kinase (FAK), an intracellular non-receptor tyrosine kinase, is highly expressed in glioblastoma cells and has been identified as a promising therapeutic target for anti-glioblastoma drug development. In this study, we report design and synthesis of a novel series of diaminopyrimidine-based small molecules that concurrently target both FAK and DNA. Among these compounds, 9f emerged as a potent dual inhibitor, demonstrating exceptional inhibitory activity against FAK (IC₅₀ = 0.815 nM) and DNA, as well as remarkable antiproliferative effects on glioblastoma cell lines U87-MG (IC₅₀ = 15 nM) and U251 (IC₅₀ = 20 nM). Furthermore, compound 9f significantly induced apoptosis in U87-MG cells and caused cell cycle arrest at the G2/M phase. Notably, in a U87-MG xenograft model, compound 9f exhibited superior antitumor efficacy. These findings underscore the potential of FAK/DNA inhibitors as a promising approach to overcome resistance.