Discovery of Novel 2,4,5-Trisubstituted Pyrimidine Derivatives as Potent and Selective FGFR Inhibitors against Gatekeeper Mutants for the Treatment of NSCLC

Fibroblast growth factor receptors (FGFRs) play a critical role in the regulation of cancer cell proliferation, differentiation, and migration. However, the development of acquired resistance to FGFR inhibitors remains a major challenge in treating non-small cell lung cancer (NSCLC), particularly due to mutations at the gatekeeper residue. In this study, we report the discovery of a series of irreversible FGFR inhibitors targeting gatekeeper mutations in FGFR1-3, utilizing a 2,4,5-trisubstituted pyrimidine scaffold. Through rational design, structure-activity relationship optimization, and pharmacokinetic evaluation, compound ng 12l emerged as a promising candidate. It demonstrated potent inhibition of FGFR1-3 gatekeeper mutations in vitro along with favorable pharmacokinetic properties. The efficacy of 12l in targeting FGFR1 gatekeeper mutations was confirmed in assays using L6-FGFR1^V561M/F cells. Furthermore, in xenograft models using both H1581 and L6-FGFR1^V561M cells, 12l exhibited robust anti-tumor activity with minimal toxicity. These findings position 12l as a promising therapeutic agent for overcoming gatekeeper-mediated resistance in NSCLC.