VX-803 (M4344)

VX-803 (M4344, ATR inhibitor 2) is an ATP-competitive, orally active, and selective inhibitor of ataxia telangiectasia and Rad3 related (ATR) kinase with Ki of < 150 pM. VX-803 (M4344) potently inhibits ATR-driven phosphorylated checkpoint kinase-1 (P-Chk1) phosphorylation with IC50 of 8 nM. VX-803 (M4344) exhibits potential antineoplastic activity.