Definition

An orally bioavailable inhibitor of the human membrane-associated tyrosine- and threonine-specific cdc2-inhibitory kinase (PKMYT1), with potential antineoplastic activity. Upon oral administration, lunresertib targets, binds to and inhibits the activity of PKMYT1. This results in the inhibition of CDK1 phosphorylation, which may promote both premature mitosis and a prolonged mitotic arrest, and lead to the accumulation of unrepaired DNA damage and apoptosis in susceptible tumor cells, such as CCNE1-overexpressing tumor cells. PKMYT1 phosphorylates CDK1 specifically when CDK1 is complexed to cyclins, which blocks progression from G2 into mitosis.