The FDA accepted a supplemental new drug application (sNDA) for niraparib (Zejula) as a first-line maintenance treatment for patients with advanced ovarian cancer who responded to platinum-based chemotherapy, regardless of their biomarker status, according to GlaxoSmithKline, the developer of the treatment.1
The sNDA is being reviewed under the Real-Time Oncology Review (RTOR) pilot program. Supporting the application was data from the randomized, double-blind, phase III PRIMA study, which demonstrated clinically meaningful outcomes of the treatment in the first-line maintenance setting. Results from the study were presented at the 2019 European Society for Medical Oncology Congress, and simultaneously published in the New England Journal of Medicine.
The PRIMA trial enrolled 733 women who responded to first-line treatment with platinum-based chemotherapy, including those at higher risk of disease progression.2 Women were randomized 2:1 to receive niraparib or placebo once daily after a response to platinum-based chemotherapy. The primary endpoint was progression-free survival (PFS) in patients who had tumors with homologous-recombination deficiency and also in those in the overall population, as determined on hierarchical testing. A prespecified interim analysis for overall survival (OS) was performed at the time of primary analysis of PFS.
In total, 373 (50.9%) patients had tumors with homologous-recombination deficiency (HRD). Among the women in this category, the median PFS was significantly longer in the group receiving niraparib than in the placebo group (21.9 months vs 10.4 months; hazard ratio [HR], 0.43; 95% CI, 0.31-0.59; P < 0.001). In the overall population, the corresponding PFS was 13.8 months and 8.2 months, respectively (HR, 0.62; 95% CI, 0.50-0.76; P < 0.001).
At the 24-month interim analysis, the rate of OS was 84% in the niraparib group and 77% in the placebo group (HR, 0.70; 95% CI, 0.44-1.11). Moreover, the most common adverse events of grade 3 or higher reported were anemia (in 31% of the participants), thrombocytopenia (28.7%), and neutropenia (12.8%). No treatment-related deaths occurred.
Niraparib is an oral, once daily PARP inhibitor that is being evaluated in multiple pivotal trials. Currently, niraparib is approved in the US as a maintenance treatment for women with recurrent ovarian cancer who are in response to platinum-based chemotherapy regardless of BRCA mutation status. Additionally, it is approved as a treatment for women with advanced ovarian cancer, following 3 or more chemotherapy regimens.
According to SEER, an estimated 22,530 new cases of ovarian cancer developed in 2019 and approximately 13,980 women died from the disease.3
1. U.S. FDA accepts GSK’s sNDA application for Zejula (niraparib) for first-line maintenance treatment for women with platinum-responsive advanced ovarian cancer [news release]. London, UK. Published February 24, 2020. gsk.com/en-gb/media/press-releases/us-fda-accepts-gsk-s-snda-application-for-zejula-niraparib-for-first-line-maintenance-treatment-for-women-with-platinum-responsive-advanced-ovarian-cancer/. Accessed February 24, 2020.
2. González-Martín A, Pothuri B, Vergote I, et al. Niraparib in Patients with Newly Diagnosed Advanced Ovarian Cancer. New England Journal of Medicine. doi:10.1056/NEJMoa1910962.
3. NCI. Cancer Stat Facts: Ovarian Cancer. NCI website. seer.cancer.gov/statfacts/html/ovary.html. Accessed February 24, 2020.