Update on Overall Survival in Phase III Trial of Niraparib for Advanced Ovarian Cancer

By: Julian Nowogrodzki, MS
Posted: Tuesday, January 21, 2025

There was no apparent difference in overall survival of patients with newly diagnosed advanced ovarian cancer who received niraparib treatment compared with a placebo, according to the phase III PRIMA/ENGOT-OV26/GOG-3012 trial, conducted by Antonio González-Martín, MD, PhD, of Clínica Universidad de Navarra, Madrid, and colleagues. Consistent with previous results, progression-free survival was better in the PARP inhibitor treatment arm than the control arm. The research was published in the Annals of Oncology.

“The long-term data support the benefit of niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer regardless of homologous recombination deficiency status,” the investigators commented.

The double-blind trial included 733 patients randomly assigned 2:1 to receive oral niraparib or a placebo once daily. Median follow-up for this analysis was 6.2 years.

The authors found there was no difference in overall survival between the treatment arms (hazard ratio [HR]= 1.01). This was true in both the homologous recombination–deficient and overall populations. The median duration of overall survival was 46.6 months with niraparib vs 48.8 months with placebo. The 5-year overall survival rates were 42% in the niraparib arm compared with 44% in the placebo arm.

However, niraparib conveyed a benefit in progression-free survival in the overall population (HR = 0.66), homologous recombination–deficient population (HR = 0.51), and homologous recombination–proficient population (HR = 0.67). This is consistent with previous results, both at the end of the trial and after 3.5 years of follow-up. The 5-year progression-free survival rate was 22% in the niraparib arm vs 12% in the placebo arm.

Many patients received additional therapy after the end of the trial, and more patients in the placebo arm received additional PARP inhibitor therapy than patients in the niraparib arm, which the investigators noted may have affected the overall survival results. Safety data were consistent with previous results on niraparib.

Disclosure: For full disclosures of the study authors, visit annalsofoncology.org.

Annals of Oncology

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