The following is a summary of “Niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer: final overall survival results from the PRIMA/ENGOT-OV26/GOG-3012 trial,” published in the September 2024 issue of Oncology by Monk et al.

The phase 3 PRIMA/ENGOT-OV26/GOG-3012 trial achieved its primary objective by demonstrating that niraparib significantly improved progression-free survival (PFS) in patients with newly diagnosed advanced ovarian cancer (aOC) who responded to first-line platinum-based chemotherapy, irrespective of homologous recombination deficiency (HRD) status. This report presents the final overall survival (OS) results and an updated PFS and long-term safety data analysis. In this double-blind, randomized trial, patients were assigned in a 2:1 ratio to receive either niraparib or placebo, with stratification based on their response to initial treatment, receipt of neoadjuvant chemotherapy, and tumor HRD status. After reaching 60% of target maturity, OS was analyzed using a stratified log-rank test and Kaplan-Meier methodology. The hierarchical OS testing assessed the overall population first, followed by the HRD-positive group. Additional secondary outcomes and long-term safety were also examined, with a cutoff date for the updated PFS analysis set for April 8, 2024.

After a median follow-up of 73.9 months, OS results showed no significant difference in the overall population between the niraparib and placebo arms. The OS hazard ratio (HR) for niraparib was 1.01 (95% CI, 0.84-1.23; P=0.8834) compared to placebo. Similar OS outcomes were observed in the HRD (HR 0.95; 95% CI, 0.71-1.29) and homologous recombination-proficient (HR 0.93; 95% CI, 0.69-1.26) subgroups. Subsequent therapy with poly (ADP-ribose) polymerase inhibitors (PARPi) was more common in the placebo arm, with 37.8% of overall patients with placebo and 48.4% of patients with HRD-positive placebo receiving subsequent PARPi therapy, compared to 11.7% and 15.8% in the niraparib arm, respectively. The 5-year PFS rate favored niraparib, with 22% in the overall population and 35% in the HRD-positive group remaining progression-free, compared to 12% and 16% for placebo, respectively. Myelodysplastic syndromes or acute myeloid leukemia were reported in fewer than 2.5% of patients (niraparib 2.3%; placebo 1.6%), and no new safety concerns emerged during the extended follow-up.

In conclusion, while OS did not differ between niraparib and placebo in patients with newly diagnosed aOC at high risk of recurrence, long-term PFS data indicate that niraparib offers a significant advantage in maintaining disease control, particularly in patients with HRD-positive. The safety profile of niraparib remained consistent with previous findings, supporting its use as a first-line maintenance therapy for aOC.

Source: sciencedirect.com/science/article/pii/S0923753424037621