Applying PARP Inhibitor Treatment Standards to Everyday Practice in Ovarian Cancer
A panel at the Society of Gynecologic Oncology’s (SGO) 2018 Annual Meeting on Women’s Cancer (March 24-27; New Orleans, LA) convened to achieve consensus on poly (ADP-ribose) polymerase (PARP) inhibitor use for the treatment and maintenance of ovarian cancer in the context of current standards.
The session, which was titled “Beyond the Guidelines: Investigator Perspectives on the Current and Future Role of PARP Inhibition in the Management of Ovarian Cancer,” was moderated by Neil Love, MD, Research to Practice, and included perspectives from four oncologists: Mansoor R Mirza, MD, medical director, Nordic Society of Gynecologic Oncology; Robert L Coleman, MD, FACOG, FACS, professor and executive director, Cancer Network Research, University of Texas MD Anderson Cancer Center; Joyce Liu, MD, MPH, department of gynecologic oncology, Dana-Farber Cancer Center; and Kathleen Moore, MD, department of obstetrics and gynecology, University of Oklahoma. The discussion was focused on the basic biology, current role, tolerability considerations, and investigational pipeline of PARP inhibitors.
Dr Love presented the panelists with various cases of patients with different characteristics, to which the panelists responded with differing best approaches to testing and treatment. Their varying preferred approaches to utilizing PARP inhibitors demonstrated the debate within the field, they noted.
Dr Coleman briefly shared the genetic testing and counseling strategies recommended by SGO, the National Comprehensive Cancer Network, and the American Society of Clinical Oncology. However, there were some points of contention among the panelists, mainly that genetic testing raises a few issues (ie providing a need for genetic counseling services, reports on unknown medical conditions) that cannot be dismissed.
“If you are already resource strapped, multi-panel testing can be more of a burden,” Dr Coleman explained.
Dr Liu furthered the discussion by providing information on the PARP inhibitors currently approved in ovarian cancer: olaparib, rucaparib, and niraparib. While all three inhibitors have demonstrated survival benefits, questions still remain as to whether PARP inhibitors should be used alone or in combination with chemotherapy. There are a few ongoing trials that are evaluating PARP inhibitors in combination with chemotherapy, but it is unknown whether this approach is superior to holding off PARP inhibitor therapy until they are needed.
Dr Moore took the conversation in the direction of tolerability considerations, which include abdominal pain; serum creatinine levels; decreases in hemoglobin, platelets, and neutrophils; and fatigue. Daily fatigue must be a top concern for oncologists, she explained, but oncologists should try to keep their patients on the active drug at a good dose for a long as possible.
Dr Mirza shared that there are more ongoing trials involving combinations with PARP inhibitors, including a highly-anticipated one for veliparib. Additionally, a few phase III trials are examining the use of PARP inhibitors with checkpoint inhibitors.
In his concluding remarks, Dr Mirza expressed his beliefs that PARP inhibitor resistance is a challenge that is likely to be overcome soon.
“I really believe this will change the standard of care of our patients upfront,” he said.—Zachary Bessette