Niraparib Maintenance Therapy in Patients With Recurrent Ovarian Cancer After a Partial Response to the Last Platinum-Based Chemotherapy in the ENGOT-OV16/NOVA Trial

PURPOSE: In the ENGOT-OV16/NOVA trial (ClinicalTrials.gov identifier: NCT01847274), maintenance therapy with niraparib, a poly(ADP-ribose) polymerase inhibitor, prolonged progression-free survival in patients with platinum-sensitive, recurrent ovarian cancer who had a response to their last platinum-based chemotherapy. The objective of the study was to assess the clinical benefit and patient-reported outcomes in patients who had a partial response (PR) and complete response (CR) to their last platinum-based therapy. PATIENTS AND METHODS: A total of 553 patients were enrolled in the trial. Of 203 patients with a germline BRCA mutation (gBRCAmut), 99 had a PR and 104 had a CR to their last platinum-based therapy; of 350 patients without a confirmed gBRCAmut (non-gBRCAmut), 173 had a PR and 177 had a CR. Post hoc analyses were carried out to evaluate safety and the risk of progression in these patients according to gBRCAmut status and response to their last platinum-based therapy. Ovarian cancer-specific symptoms and quality of life were assessed using the Functional Assessment of Cancer Therapy-Ovarian Symptom Index. RESULTS: Progression-free survival was improved in patients treated with niraparib compared with placebo in both the gBRCAmut cohort (PR: hazard ratio [HR], 0.24; 95% CI, 0.131 to 0.441; P < .0001; CR: HR, 0.30; 95% CI, 0.160 to 0.546; P < .0001) and the non-gBRCAmut cohort (PR: HR, 0.35; 95% CI, 0.230 to 0.532; P < .0001; CR: HR, 0.58; 95% CI, 0.383 to 0.868; P = .0082). The incidence of any-grade and grade 3 or greater adverse events was manageable. No meaningful differences were observed between niraparib and placebo in PR and CR subgroups with respect to patient-reported outcomes. CONCLUSION: Patients achieved clinical benefit from maintenance treatment with niraparib regardless of response to the last platinum-based therapy.