ChEBI: Olaparib is a member of the class of N-acylpiperazines obtained by formal condensation of the carboxy group of 2-fluoro-5-[(4-oxo-3,4-dihydrophthalazin-1-yl)methyl]benzoic acid with the free amino group of N-(cyclpropylcarbonyl)piperazine; used to treat advanced ovarian cancer. It has a role as an antineoplastic agent, an EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor and an apoptosis inducer. It is a N-acylpiperazine, a member of cyclopropanes, a member of monofluorobenzenes and a member of phthalazines.NCI Thesaurus (NCIt): Olaparib is a small molecule inhibitor of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) with potential chemosensitizing, radiosensitizing, and antineoplastic activities. Olaparib selectively binds to and inhibits PARP, inhibiting PARP-mediated repair of single strand DNA breaks; PARP inhibition may enhance the cytotoxicity of DNA-damaging agents and may reverse tumor cell chemoresistance and radioresistance. PARP catalyzes post-translational ADP-ribosylation of nuclear proteins and can be activated by single-stranded DNA breaks.