Prexasertib dimesylate (LY2606368 dimesylate) is a highly selective ATP-competitive second-generation inhibitor of checkpoint kinase 1 (CHK1). With a K i of 0.9 nM and an IC 50 of <1 nM, Prexasertib dimesylate effectively inhibits CHK2 (IC 50 = 8 nM) and RSK1 (IC 50 = 9 nM). Its mechanism of action involves inducing double-stranded DNA breakage and replication catastrophe, ultimately leading to apoptosis. Moreover, Prexasertib dimesylate demonstrates potent anti-tumor activity.