Compared to PARPi, such as Olaparib, SYX3759 shows selective and potent cytotoxicity on a broader spectrum of homologous recombination deficient (HRD) tumors both in vitro and in vivo….Collectively, SYX3759 is a potent PARG inhibitor both in vitro and in vivo warranting future clinical trials for the treatment of HRD cancers and beyond.