Design, synthesis, and biological evaluation of 2-aminopyrimidine-5-carboxamide derivatives as potent selective Wee1 inhibitors.

Wee1 is a serine/threonine kinase that plays an important role in regulating DNA damage response and cell cycle checkpoints. Inhibition of Wee1 could abrogate cell cycle arrest, exacerbate DNA damage, and induce mitotic catastrophe and apoptosis. Herein, a novel series of 2-aminopyrimidine-5-carboxamide derivatives were designed, synthesized, and evaluated as Wee1 inhibitors. Among them, compound WC-27 exhibited excellent inhibitory activity against Wee1 (IC50 = 2.11 nM) and high selectivity over PLK1 (IC50 > 1000 nM), suggesting that it may reduce off-target effects on PLK1 and thereby potentially mitigate the myelosuppression associated with Wee1 inhibitors. Meanwhile, it displayed acceptable antiproliferative activity against NCI-H1299 cell line with an IC50 value of 1.05 μM. Further investigation showed that compound WC-27 could arrest NCI-H1299 cells in S phase and induce apoptosis in a dose-dependent manner. Moreover, compound WC-27 displayed moderate liver microsomal stability and an excellent pharmacokinetic profile (AUC0-t = 2370 ng h mL-1, oral bioavailability of 49.5%) in Sprague-Dawley rats, acceptable PPB, low risk of drug-drug interactions and no apparent toxicity was observed in the acute toxicity assay. Overall, compound WC-27 exhibited high selectivity over PLK1. This favorable profile may mitigate the risk of PLK1-related off-target toxicities such as myelosuppression, a well-recognized safety liability for reported Wee1 inhibitors. Collectively, these results indicate that compound WC-27 is a promising Wee1 inhibitor.