Niraparib (MK-4827) hydrochloride is a highly potent PARP inhibitor with IC50 of 3.8 nM/2.1 nM for PARP1/PARP2.
MK-4827 inhibits PARP activity with EC50=4 nM in a whole cell assay, and inhibits proliferation of cancer cells with mutant BRCA-1 and BRCA-2 with CC50 in the 10−100 nM range.
MK-4827 is well tolerated in vivo and demonstrates efficacy as a single agent in a xenograft model of BRCA-1 deficient cancer.
