The FDA has approved niraparib (Zejula, Tesaro, Inc.) for the maintenance treatment of adult women with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer whose tumors have shown a complete or partial response to platinum-based chemotherapy.
Epithelial ovarian, fallopian tube, or primary peritoneal cancer affects the tissue covering the ovary or lining the fallopian tube or peritoneum. The National Cancer Institute estimates that more than 22,000 women will be diagnosed with these cancers in 2017 and that 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 slow-down or stoppage of tumor growth.
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 two prior treatments of platinum-based chemotherapy and who had experienced a complete or partial response to their most recent chemotherapy treatment.
Patients were tested to determine whether they had a deleterious or germline BRCA mutation. The trial measured progression-free survival (PFS) in patients with and without the mutation. The median PFS 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 PFS 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, leukopenia, heart palpitations, nausea, constipation, vomiting, abdominal distention, mucositis, diarrhea, dyspepsia, dry mouth, fatigue, decreased appetite, urinary tract infection, liver problems, 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 harm a developing fetus or a newborn baby.
The FDA granted this application fast track, priority review, breakthrough therapy, and orphan drug designations.
Source: FDA; March 27, 2017.