Niraparib extends PFS in ovarian cancer

Niraparib significantly extended PFS compared with placebo among women with recurrent ovarian cancer, according to phase 3 study results released today by the drug’s manufacturer.

Researchers observed the PFS benefit among women regardless of germline BRCA mutation status.

Niraparib (Tesaro), a PARP inhibitor, also benefited women who did not have germline BRCA mutations but had homologous recombination-deficient tumors.

The phase 3 NOVA trial — a double blind, placebo-controlled, international study — included more than 500 women with recurrent ovarian cancer who were in response to their most recent platinum-based chemotherapy. There is no FDA-approved therapy for maintenance treatment of this patient population.

Researchers enrolled patients into two cohorts based on germline BRCA mutation status. The cohort of noncarriers included patients with homologous recombination-deficient tumors.

Investigators assigned patients in each cohort 2:1 to 300 mg daily niraparib or placebo. Treatment continued until progression.

PFS served as the primary endpoint. Secondary endpoints included patient-reported outcomes, chemotherapy-free interval length, OS, and safety and tolerability.

Niraparib conferred a statistically significant PFS benefit to germline BRCA mutation carriers (median, 21 months vs. 5.5 months; HR = 0.27; P < .0001), all noncarriers (median, 9.3 months vs. 3.9 months; HR = 0.45; P < .0001) and noncarriers with homologous recombination-deficient tumors (median, 12.9 months vs. 3.8 months; HR = 0.38; P < .0001).

“Importantly, these results show activity of niraparib in a population of ovarian cancer patients beyond those with germline BRCA mutations,” Mary Lynne Hedley, PhD, president and chief operating officer of Tesaro, said in a company-issued press release. “In keeping with our mission of responsible drug development, NOVA was designed to define those patients most likely to benefit from niraparib treatment and, in so doing, optimize the benefit–risk profile for patients.”

The most common treatment-emergent grade 3 or grade 4 adverse events included thrombocytopenia (28.3%), anemia (24.8%) and neutropenia (11.2%). Adverse events for all patients were managed with dose modifications.

Incidence of myelodysplastic syndrome and acute myeloid leukemia was comparable between the niraparib and placebo groups (1.3% vs. 1.2%).

No patients died during study treatment.

Complete data from the trial is scheduled for presentation at the European Society for Medical Oncology Congress in October, Hedley said.