Niraparib tosylate (MK-4827 tosylate) is a highly potent and orally bioavailable PARP1 and PARP2 inhibitor with an IC50 of 3.8 and 2.1 nM, respectively; with significant activity in cancer cells with mutant BRCA-1 and BRCA-2; >330-fold selective against PARP3, V-PARP, and Tank1. Niraparib tosylate leads to inhibition of repair of DNA damage, activates apoptosis, and shows anti-tumor activity.
Niraparib is a novel oral poly(ADP-ribose)polymerase (PARP) inhibitor efficacious in BRCA-1 and -2 mutant tumors.
In a whole-cell assay, Niraparib (MK-4827) tosylate hydrate inhibits PARP activity with EC50=4 nM and EC90=45 nM. Niraparib tosylate hydrate inhibits the proliferation of cancer cells with mutant BRCA-1 and BRCA-2 with CC50 in the 10-100 nM range. Niraparib tosylate hydrate displays excellent PARP 1 and 2 inhibition with IC50=3.8 and 2.1 nM, respectively, and in a whole-cell assay.
Niraparib tosylate hydrate inhibits PARP within 15 minutes of treatment, reaching about 85% inhibition in the A549 cells at 1 h and about 55% inhibition at 1 h for the H1299 cells.
