PARP Inhibitor Leads to Symptom-Free Time for Patients with Ovarian Cancer

Treatment with niraparib (Zejula) can significantly prolong the time without symptoms or toxicity (TWiST) for patients with recurrent ovarian cancer that is in remission through platinum-based chemotherapy, according to a new study led by researchers at Dana-Farber Cancer Institute.

In the study, published in the Journal of Clinical Oncology, researchers examined data from 553 participants in the phase 3 ENGOT-OV16/NOVA trial, which compared niraparib with a placebo in women with platinum-sensitive ovarian cancer who had received at least 2 courses of platinum-based chemotherapy. Results were calculated for patients with an inherited (germline) BRCA gene mutation and for those without this mutation.

According to the press release, TWiST is a statistical measure that provides an estimate of how long a patient is free of disease progression and toxicity from treatment and, therefore, is likely to maintain a good quality of life. In this study, investigators first estimated the mean progression-free survival (PFS) and mean time with toxicity for patients treated with niraparib and those given a placebo. Toxicity was defined as grade 2 or higher fatigue, nausea, or vomiting. By calculating the difference in mean PFS and mean time with toxicity, researchers arrived at TWiST for each group.

The mean TWiST for women receiving niraparib maintenance therapy was more than 4 times higher than for patients receiving a placebo in the BRCA-mutant group and two times higher in the non-mutant group.

Niraparib, a poly (ADP-ribose) polymerase (PARP) inhibitor, undermines cancer cells by lowering their ability to repair damage to their DNA. The PARP inhibitor was approved by the FDA in 2017 as a maintenance treatment for women with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are responding to platinum chemotherapy.

Reference

• Study shows benefit of PARP inhibitor for some ovarian cancer patients [press release]. Dana-Farber Cancer Institute website. Published on September 16, 2019. https://www.dana-farber.org/newsroom/news-releases/2019/study-shows-benefit-of-parp-inhibitor-for-some-ovarian-cancer-patients/. Accessed September 19, 2019.