Where Do We Stand on the Integration of PARP Inhibitors for the Treatment of Breast Cancer?

PURPOSE OF REVIEW: To provide an overview of the clinical development of poly(ADP-ribose) polymerase inhibitors (PARPi) in breast cancer to date and to review existing challenges and future research directions. RECENT FINDINGS: We summarize the clinical development of PARPi in breast cancer from bench to bedside, and discuss the results of recent phase 3 trials in patients with metastatic breast cancer (MBC) and germline mutations in BRCA1/2 (gBRCAm). We will also provide an update regarding mechanisms of action and resistance to PARPi, and review clinical trials of PARPi as monotherapy or in combination regimens. PARPi are a novel treatment approach in persons with gBRCA1/2m-associated MBC. Going forward, the clinical applicability of these compounds outside the gBRCAm setting will be studied in greater detail. The identification of accurate predictive biomarkers of response is a research priority.