Used primarily in the treatment of ovarian, fallopian tube, and peritoneal cancers, especially in patients who have recurrent disease and are in complete or partial response to platinum-based chemotherapy. It is also approved for use in certain patients with breast cancer who have inherited BRCA mutations. As a PARP inhibitor, it works by blocking enzymes involved in DNA repair, leading to cancer cell death. The drug is taken orally and allows for targeted therapy with improved progression-free survival in clinical settings.