The Food and Drug Administration’s recent approval of Zejula for certain patients with advanced ovarian, fallopian tube or primary peritoneal cancer was the first PARP inhibitor approved for the treatment, not the maintenance, of these women.
BY Kristie L. Kahl
The Food and Drug Administration (FDA)’s recent approval of Zejula (niraparib) for certain patients with advanced ovarian, fallopian tube or primary peritoneal cancer was the first PARP inhibitor approved for the treatment, not the maintenance, of these women, regardless of BRCA mutation status, according to Dr. Debra Richardson.
The approval, in particular, is intended for women who have been treated with three or more prior chemotherapy regimens and whose cancer is associated with homologous recombination deficiency (HRD)-positive status – which can indicate whether a patient is a good candidate for PARP inhibitor therapy.
“This is the first time a PARP inhibitor has been FDA approved for the treatment (rather than maintenance) of women with recurrent ovarian cancer with or without BRCA mutations. In women who do not have a germline BRCA mutation, testing on their tumor needs to be done to assess if the tumor is HRD-positive,” said Richardson, who is an associate professor in the section of gynecologic oncology at the University of Oklahoma and a member of the National Ovarian Cancer Coalition Board of Directors and Medical & Scientific Advisory Board.
HRD, a genetic factor that can be present among women who have the BRCA mutation, means that a woman’s cancer cells have trouble repairing themselves, which can in turn make these malignant cells easier to attack and treat.
A patient’s HRD status is determined by whether or not they have a deleterious or suspected deleterious BRCA mutation or if their genomic instability with disease progression is greater than six months after their last response to treatment with platinum-based chemotherapy.
The agency’s approval is based on results from the single-arm, phase 2 QUADRA trial. The researchers evaluated the PARP inhibitor in 98 women with HRD-positive advanced ovarian cancer, who demonstrated an objective response rate of 24%, all of which were partial responses. Moreover, median duration of response was 8.3 months.
“It does not improve their overall survival. For women who responded, the median duration of response was 8 months, which is impressive,” Richardson said.
In patients whose HRD status included a BRCA mutation, the objective response rate was 39% in patients with platinum sensitivity, 29% in those with platinum resistance and 19% in patients with platinum-refractory disease.
Side effects included thrombocytopenia, anemia, neutropenia, nausea, vomiting and fatigue. Reactions that warranted dose reduction or interruption occurred in 73% of patients.
“This approval is great news for women with recurrent ovarian cancer who have received multiple lines of therapy and are HRD-positive. Niraparib is an oral medication that is taken once a day, and has tolerable side effects,” Richardson said. “It is always important to discuss potential side effects and how they will be managed. Women should know how frequent blood draws need to be done for monitoring, and how often they will see their providers.”
At the time of data cut-off on April 11, 2018, 21 patients remained on therapy.
“The goal is to help women with recurrent ovarian cancer live as long and as well as possible,” Richardson concluded. “More treatment options help to achieve those goals.”
Read CURE’s original coverage of the FDA’s approval of Zejula for an advanced ovarian cancer subset