Potent PARP inhibitor (IC50 values are 2, 5 and 200 nM for PARP2, PARP1 and PARP3, respectively). Exhibits anticancer effects in BRCA1 mutant, but not wild-type breast cancer cell lines in vitro. Inhibits growth of olaparib-resistant mammary tumors in a mouse model and is a poor substrate for the P-gp transporter. Orally bioavailable. Purity 98%. MW (observed): 395.43