PFS benefit with niraparib as first-line maintenance in ovarian cancer

Niraparib significantly improved progression-free survival (PFS) in patients with newly diagnosed advanced ovarian cancer, including patients at high risk of progressive disease. Niraparib should be considered as a treatment option for patients with advanced ovarian cancer after completion of first-line chemotherapy.

Lead study author Prof. Antonio González Martín (Clinica Universidad de Navarra, Spain) presented the results from the phase 3 PRIMA/ENGOT-OV26/GOG-3012 study in the Presidential Symposium [1]. The study investigated the efficacy and safety of the oral poly-ADP ribose polymerase (PARP) inhibitor niraparib after response to platinum-based chemotherapy in patients with newly-diagnosed ovarian cancer, including those at high risk of relapse. Overall, niraparib treatment resulted in a 38% reduction in the risk of disease progression or death in the overall population (HR 0.62; 95% CI 0.50-0.75; P<0.001).

In particular, results of the trial demonstrated a clinically meaningful reduction in risk of progression in women across biomarker subgroups (see Table). For example, patients whose tumours harboured a BRCA mutation experienced a marked risk reduction of 60% (HR 0.40; 95% CI 0.27-0.62; P<0.001). Furthermore, BRCA wild-type tumours but with homologous recombination-deficiency had a risk reduction of 50% (HR 0.50; 95% CI 0.30-0.83; P=0.006). Homologous recombination-proficient tumours, however, had a risk reduction of 32% (HR 0.68; 95% CI 0.49-0.94; P=0.020).

Table. Summary of results



mPFS, Median progression free survival; placebo, PBO; CI, confidence interval, homologous recombination-deficient positive, HRDpos, NE not estimable.

Although median overall survival was not yet reached, a pre-planned interim analysis supported a trend in improved overall survival, favouring over placebo. In the overall population, niraparib showed 84% overall survival vs 77% from the placebo arm alive at 24 months. Patients with homologous recombination-deficient tumours had 91% overall survival vs 85%, and homologous recombination-proficient tumours were associated with 81% vs 59%.

No new safety signals were identified for niraparib, with the most common treatment-emergent adverse event being reversible myelosuppression, according to the study. Dr Gonzalez indicated that these data support niraparib monotherapy after first-line platinum-based chemotherapy as a new standard of care.

1. González Martín et al. ESMO Congress 2019. Abstract LBA1.

Posted on 26 November, 201915 February, 2024