What is MK-1775? MK-1775 is an inhibitor of the checkpoint kinase Wee1 (IC50 = 5.2 nM).1 It has been shown to inhibit the phosphorylation of Cdc2 at tryosine-15, which abrogates the G2 DNA damage checkpoint.1 In p53-deficient tumors that rely solely on the G2 checkpoint upon DNA damage, MK-1775, in combination with DNA-damaging chemotherapeutic agents, is reported to induce apoptosis …