On the final day of the Oncology Clinical Pathways Congress (October 13, 2019; Boston, MA), Alexander B Olawaiye, MD, MRCOG, FACOG, FACS, University of Pittsburgh School of Medicine, presented on strategies to improve the incorporation of guideline recommendations into clinical pathways for ovarian cancer, particularly with regard to PARP inhibitors.
He began his presentation by informing the audience that from 1978 to 2013, only seven chemotherapy agents were approved by the FDA for ovarian cancer. Outside of clinical trials, there were no other options for patients needing ovarian cancer therapy at that time. However, from 2014 to 2018, three treatment agents (olaparib, rucaparib, and bevacizumab) as well as four maintenance agents (niraparib, olaparib, rucaparib, and bevacizumab) were approved in this setting.
Dr Olawaiye proceeded to detail the target population for these treatments, how to determine which treatment options to use for specific patients, and how to determine which maintenance options should be used for specific patients. This discussion included a variety of presented research published within the past decade related to targeted therapy as primary treatment, survival outcomes associated with PARP inhibitor maintenance therapy, PARP inhibitor maintenance in recurrent disease, and toxicity related to PARP inhibitors.
One particular study that he highlighted was the SOLO1 study – a phase III trial of maintenance therapy with a PARP inhibitor (olaparib) following first-line platinum-based chemotherapy in newly diagnosed patients with advanced ovarian cancer and a BRCA1/2 mutation. The study included 391 patients randomly assigned (2:1) and stratified by response to prior chemotherapy to receive either olaparib (n = 260) or placebo (n = 131).
Investigator progression-free survival at 3 years showed a significantly higher rate for those who received olaparib compared with those who received placebo (60.4% vs 26.9%, respectively). Similarly, the median time to first subsequent therapy or death favored patients in the olaparib arm (51.8 vs 15.1 months, respectively) as did the median time to second subsequent therapy or death (median not reached vs 40.7 months, respectively).
The results of the SOLO1 study has subsequently led to olaparib being considered an effective first-line therapy option for all patients with a BRCA1/2 mutation.
In an attempt to further elucidate the first-line ovarian cancer landscape and determine potential pathway considerations in this setting, Dr Olawaiye concluded his presentation by asking the audience to consider the results of three other significant clinical trials. Now that the results of the PRIMA study are positive, it may be justifiable to consider niraparib as a first-line option for all patients with high-grade ovarian cancer, he noted. The results of PAOLA-1 (olaparib plus bevacizumab) and VELIA (veliparib) studies will undoubtedly have an impact on this consideration as well, he acknowledged, as well as what course of treatment to consider after recurrence on niraparib, olaparib plus bevacizumab, and veliparib.—Zachary Bessette