Dr. Westin on PARP Resistance in Ovarian Cancer

Shannon N. Westin, MD, MPH, clinical investigator, Department of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, discusses resistance to PARP inhibitors in patients with ovarian cancer.

As of May 2018, there are now 3 FDA-approved PARP inhibitors in the maintenance setting—niraparib (Zejula), olaparib (Lynparza), and rucaparib (Rubruca)—for patients who are in complete or partial response to platinum-based chemotherapy. PARP resistance, Westin says, is an area of ongoing research. The patient population Westin predominantly sees become resistant to PARP inhibitors is what they call treated in the “treatment phase,” as opposed to the maintenance phase. These are patients with germline or somatic BRCA mutations who were treated with a single-agent PARP inhibitor in the recurrent setting.

Researchers are just starting to see patients who received PARP inhibitor maintenance with growth, but Westin says that is a different group. There are a number of different combination strategies to try to overcome resistance, such as PARP inhibitors with immunotherapy or other targeted agents.