When utilized as maintenance therapy after frontline treatment of ovarian cancer in patients with BRCAwt tumors, niraparib improved progression-free survival (PFS), even in the most difficult-to-treat patients.
Niraparib is a poly (ADP-ribose) polymerase inhibitor that has been approved as maintenance therapy for the treatment of patients with newly diagnosed advanced or platinum-sensitive, recurrent ovarian cancer. In the United States, niraparib has been approved for the treatment of patients with ovarian cancer who have received 3 lines of therapy and whose cancer is either homologous recombination deficient (HRd), platinum-sensitive disease or BRCA mutated.
Niraparib has been shown to significantly improve PFS in patients with newly diagnosed, advanced ovarian cancer that responded to first-line, platinum-based chemotherapy (hazard ratio, 0.62; 95% confidence interval, 0.50-0.76) in the PRIMA/ENGOT-OV26/GOG-3012 trial. At the European Society of Gynaecological Oncology 2020 Virtual Conference, Elena Ioana Braicu and colleagues presented the findings of the study evaluating the efficacy of niraparib in patients based on BRCA wild-type (BRCAwt) status.
In this double-blind, placebo-controlled phase 3 trial, niraparib was studied in patients with newly diagnosed, advanced, high-grade serous or endometrioid ovarian, primary peritoneal, or fallopian tube cancer with a complete response or partial response to first-line, platinum-based chemotherapy. Patients were randomized 2:1 to receive either niraparib or placebo once daily. The primary end point was PFS. BRCA and HRd status were determined by tumor samples at screening. Of the 733 randomized patients included in the study, 473 (64.5%) patients had BRCAwt tumors, and 74 patients had unknown BRCA status. Of the patients with BRCAwt, 31.7% had HRd/BRCAwt tumors, 15.7% had homologous recombination not determined/BRCAwt tumors, and 52.6% had homologous recombination proficient (HRp)/BRCAwt tumors.
A clinically meaningful PFS benefit was observed in patients with BRCAwt tumors treated with niraparib. In the BRCAwt cohort, niraparib-treated patients had a median PFS of 10.9 months compared with 7.4 months in the placebo group. In the HRd/BRCAwt cohort, the niraparib-treated patients had a median PFS of 19.6 months compared with 8.2 months in the placebo cohort. In the HRp/BRCAwt cohort, the median PFS in the niraparib-treated patients was 8.1 months compared with 5.4 months in the placebo group.
When utilized as maintenance therapy after frontline treatment of ovarian cancer in patients with BRCAwt tumors, niraparib improved PFS, even in the most difficult-to-treat subgroup of patients with BRCAwt and HRp tumors.
Source: Braicu EI, et al. Int J Gynecol Cancer. 2020;30(4_suppl). Abstract 364.