Niraparib Maintenance Prolongs PFS in Recurrent Ovarian Cancer

Maintenance therapy with niraparib significantly prolongs progression-free survival, in contrast with placebo, for all study populations of patients with platinum-sensitive, recurrent ovarian cancer, according to a study presented at the European Society for Medical Oncology (ESMO) 2016 Congress.¹

Niraparib is an oral poly(adenosine diphosphate [ADP]–ribose) polymerase (PARP) 1/2 inhibitor that has demonstrated clinical activity among patients with ovarian cancer. Researchers evaluated the efficacy of niraparib as maintenance therapy versus placebo among patients with platinum-sensitive, recurrent ovarian cancer.

For the international, double-blind, phase 3 trial (ClinicalTrials.gov Identifier: NCT01847274), investigators enrolled 553 patients with or without a germline BRCA mutation. Of those, 40% had received more than 2 prior lines of therapy, and 76% had stage IIIC or IV disease.

Niraparib significantly reduced the risk of progression or death by 73% compared with placebo among patients with germline BRCA mutations (hazard ratio [HR], 0.27; 95% CI, 0.173-0.410; P < .0001). Median progression-free survival was 21.0 months (95% CI, 12.9-not reached) with niraparib versus 5.5 months (95% CI, 3.8-7.2) with placebo.

Among those without germline BRCA mutations, niraparib significantly improved progression-free survival by 55% versus placebo (HR, 0.45; 95% CI, 0.338-0.607; P < .0001). Median progression-free survival was 9.3 months (95% CI, 7.2-11.2) in the niraparib group compared with 3.9 months (95% CI, 3.7-5.5) in the placebo arm.

Niraparib reduced the risk of progression or death by 62% among patients without germline BRCA mutations whose tumors were retrospectively defined as deficient in homologous recombination (HRD) by the myChoice HRD test (HR, 0.38; 95% CI, 0.243-0.586; P < .0001). In that cohort, median progression-free survival was 12.9 months (95% CI, 8.1—15.9) and 3.8 months (95% CI, 3.5-5.7) for niraparib and placebo, respectively.

The most common grade 3 to 4 treatment-emergent adverse events in the niraparib arm were thrombocytopenia, anemia, and neutropenia. No patients died during study treatment.                                 

Reference

1. Mirza M, Monk BJ, Oza A, et al. A randomized, double-blind phase 3 trial of maintenance therapy with niraparib vs placebo in patients with platinum-sensitive recurrent ovarian cancer (ENGOT-OV16/NOVA trial). Paper presented at: European Society for Medical Oncology (ESMO) 2016 Congress; October 7-11, 2016; Copenhagen, Denmark.