The U.S. Food and Drug Administration (FDA) has approved niraparib (Zejula) for the maintenance treatment of adult patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer, whose tumors have achieved complete or partial response to platinum-based chemotherapy.
“Maintenance therapy is an important part of a cancer treatment regimen for patients who have responded positively to a primary treatment,” said Richard Pazdur, MD, Acting Director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research and Director of the FDA’s Oncology Center of Excellence. “[Niraparib] offers patients a new treatment option that may help delay the future growth of these cancers, regardless of whether they have a specific genetic mutation.”
Epithelial ovarian, fallopian tube, or primary peritoneal cancer is a cancer of the peritoneum. The National Cancer Institute estimates that more than 22,000 women will be diagnosed with these cancers in 2017, and more than 14,000 will die of these diseases.
Niraparib is a poly ADP-ribose polymerase (PARP) inhibitor that blocks an enzyme involved in repairing damaged DNA. By blocking this enzyme, DNA inside the cancerous cells may be less likely to be repaired, leading to cell death and possibly a slowdown or stoppage of tumor growth.
Safety and Efficacy Results
The safety and efficacy of niraparib were studied in a randomized trial of 553 patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer, who had received at least 2 prior treatments of platinum-based chemotherapy and who had experienced a complete or partial response to their most recent chemotherapy treatment. Patients were tested with an FDA-approved test to determine whether they had a deleterious or germline BRCA mutation. The trial measured progression-free survival in patients with and without the mutation. The median progression-free survival for patients taking niraparib who had a germline BRCA mutation was 21 months compared to 5.5 months for the same patient population taking a placebo. The median progression-free survival for patients taking niraparib who did not have a germline BRCA mutation was 9.3 months compared to 3.9 months for the same patient population taking a placebo.
Common side effects of niraparib include anemia, thrombocytopenia, neutropenia or leukopenia, heart palpitations, nausea, constipation, vomiting, abdominal distention, mucositis, diarrhea, dyspepsia, dry mouth, fatigue, decreased appetite, urinary tract infection, aspartate transaminase/alanine transaminase elevation, myalgia, back pain, arthralgia, headache, dizziness, dysgeusia, insomnia, anxiety, nasopharyngitis, dyspnea, cough, rash, and hypertension. Niraparib is associated with serious risks, such as hypertension, hypertensive crisis, myelodysplastic syndrome, acute myeloid leukemia, and bone marrow suppression. Women who are pregnant or breastfeeding should not take niraparib because it may cause harm to a developing fetus or a newborn baby.
The FDA granted this application Fast Track, Priority Review, and Breakthrough Therapy designations. Niraparib also received Orphan Drug designation specifically for its use in treating recurrent epithelial ovarian cancer. This designation provides incentives to assist and encourage the development of drugs for rare diseases. ■