– TH9619 (TH-9619) is a potent and selective inhibitor of folate metabolism enzyme MTHFD2 with IC50 of 47 nM.TH9619 demonstrated efficacy on HL-60 cell viability with EC50 of 11 nM.TH9619 potently inhibits related MTHFD proteins MTHFD2L and MTHFD1-(DC) with IC50 of 47 and 16 nM, respectively.TH9619 displays high potency and cancer selectivity in AML models. induce thymine-less DNA damage and apoptosis, causes uracil misincorporation into DNA, sensitize cancer cells to ATR-signaling blockade.TH9619 impairs cancer progression in vivo.TH9619 displays high selectivity toward binding and stabilizing MTHFD2 over other common folate metabolism targets such as DHFR, thymidylate synthase (TYMS), serine hydroxymethyltransferase (SHMT) 1 and SHMT2.