Maintenance Therapy With Niraparib Offers Superior PFS in Recurrent Ovarian Cancer
By Walter Alexander
COPENHAGEN, Denmark -- October 12, 2016 -- Niraparib demonstrated superior progression-free survival (PFS) compared with placebo as maintenance therapy among patients with recurrent ovarian cancer, according to results of the phase 3 ENGOT-OV16/NOVA trial presented here at the 41st European Society for Medical Oncology (ESMO) Congress.
The broad population of patients with ovarian cancer who would benefit from treatment with the selective poly ADP ribose polymerase (PARP 1/2) inhibitor represents 70% of all ovarian cancer patients, noted Mansoor Raza Mirza, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark, speaking at a press conference on October 8.
The current treatment landscape for recurrent ovarian cancer is limited by cumulative toxicities and a lack of subsequent benefit with platinum-based chemotherapy, Dr. Mirza explained. Moreover, maintenance therapy with bevacizumab (approved only in the EU) can only be administered once, and confers just a few months of PFS benefit. The PARP inhibitor olaparib is approved only for the 10% to 15% of patients with a germline breast cancer (BRCA) mutation.
The ENGOT-OV16/NOVA hypothesis was that niraparib would provide a clinical benefit to all patients with platinum-sensitive recurrent ovarian cancer who are responsive to platinum, regardless of BRCA mutation status. The study included 553 patients randomised 2:1 to niraparib 300 mg once daily or placebo, and stratified according to status as germline BRCA mutation (gBRCAmut; n = 203) or non-gBRCAmut (n = 350). After 4 to 6 cycles of platinum-based therapy, patients received the study regimen until progression.
Niraparib improved the primary endpoint of PFS significantly compared with placebo in both cohorts, as well as in all subgroups. Median PFS with niraparib was 21.0 months compared with 5.5 months for placebo in the gBRCAmut group (hazard ratio [HR] = 0.27; 95% confidence interval [CI], 0.173-0.410; P < .0001). In the non-germline BRCA mutation group, median PFS was 9.3 months for niraparib versus 3.9 months for placebo (HR = 0.45; 95% CI, 0.338-0.607; P < .0001), and 12.9 versus 3.8 months in a subgroup of the non-mutation cohort who had homologous recombination DNA repair deficiencies (HR = 0.38; 95% CI, 0.243-0.586; P < .0001).
Dr. Mirza reported grade 3 and 4 adverse events in more than 10% of patients receiving niraparib, with a rate of 28% for thrombocytopaenia, 25% for anaemia, and 11% for neutropaenia. Generally, dose adjustments resolved these issues, and patient-reported quality of life was similar for both study arms.
“Pending approval, these landmark results could change the way we treat this disease, and [could] warrant niraparib maintenance treatment for the whole study population,” Dr. Mirza concluded.
Funding for this study was provided by Tesaro Inc., Waltham, Massachusetts.
[Presentation title: 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). Abstract LBA3]