Data presented at the 2021 ASCO Annual Meeting on 3 prominent trials of niraparib as maintenance for ovarian cancer after a positive response to platinum-based chemotherapy further support the use of the agent in multiple settings.
Compiling results from 3 phase 3 trials of niraparib (Zejula) maintenance in patients with BRCA-mutant ovarian cancer following platinum response in both front- and later-line settings indicate significant reduction in the risk of disease progression or death with the PARP inhibitor, according to an analysis presented in a poster at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting.
Researchers assessed the efficacy and safety of niraparib compared with placebo in patients with BRCA-mutated ovarian cancer from 3 trials: ENGOT-OV16/NOVA (NCT01847274; n = 203), PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016; n = 223) and NORA (NCT03705156; n = 100).
“Patients with BRCA-mutated ovarian cancer derived a significant progression-free survival [PFS] benefit from niraparib maintenance treatment across all three trials in first-line and recurrent settings after response to platinum-based chemotherapy,” Antonio Gonzalez Martin, MD, co-director of the department of medical oncology at Clinica Universidad de Navarra in Spain and president of the Spanish Ovarian Cancer Group (GEICO), said during the meeting.
In particular, patients in the PRIMA trial had newly diagnosed advanced ovarian cancer and responded to first-line platinum-based chemotherapy. Patients in the ENGOT-OV16/NOVA and NORA trials had platinum-sensitive, recurrent ovarian cancer. All trials included a subgroup analysis by BRCA mutation status.
Of the 526 patients in all 3 trials, the most common mutation was in BRCA1, accounting for 60.6% to 80% of BRCA mutations.
Niraparib derived a significant PFS benefit compared with placebo in patients with BRCA mutations from the PRIMA (HR, 0.4; 95% CI, 0.27-0.62), NOVA (HR, 0.27; 95% CI, 0.17-0.41) and NORA trials (HR, 0.22; 95% CI, 0.12-0.39). No differences were observed in the PRIMA trial in patients with BRCA1 and BRCA2 mutations. For patients in the NOVA trial, hazard ratios for PFS were 0.39 for those with BRCA1 mutations (95% CI, 0.23-0.66) and 0.12 for those with BRCA2 mutations (95% CI, 0.05-0.33).
Any-grade hematological treatment-emergent adverse events (TEAEs) occurred in at least 20% of patients assigned niraparib. This was also seen for TEAEs of any grade.
“The most common treatment-emergent adverse events of any grade were thrombocytopenia, anemia, neutropenia, and nausea across all three trials,” Gonzalez Martin said during the presentation. “The most common grade 3 or 4 hematological treatment-emergent adverse events were thrombocytopenia, anemia, and neutropenia.”
For nonhematological treatment-emergent adverse events, the most common of any grade included nausea, constipation and fatigue, all of which were mainly mild or low grade, Gonzalez Martin said.
“Importantly, no new safety signals were identified,” Gonzales Martin added.
Gonzalez Martin A, Matulonis UA, Korach J, et al. Niraparib efficacy and safety in patients with BRCA mutated (BRCAm) ovarian cancer: Results from three phase 3 niraparib trials. J Clin Oncol. 2021;39(suppl 15):5518. doi:10.1200/JCO.2021.39.15_suppl.5518