Niraparib maintenance does not improve overall survival (OS) in patients with platinum-sensitive recurrent ovarian cancer, according to research presented at the 2023 SGO Annual Meeting on Women’s Cancer.1
Updated data from the phase 3 ENGOT-OV16/NOVA trial showed no significant difference in OS among patients who received niraparib maintenance after platinum-based chemotherapy and those who received placebo maintenance.
However, the OS analysis was confounded by differences in treatment given after disease progression, according to study presenter Ursula A. Matulonis, MD, of Dana-Farber Cancer Institute and Harvard Medical School in Boston.
The ENGOT-OV16/NOVA trial (ClinicalTrials.gov Identifier: NCT01847274) included 553 patients with recurrent ovarian, fallopian tube, or primary peritoneal cancer. Patients had achieved a complete or partial response of at least 6 months to second-line or later platinum-based chemotherapy.
The patients were divided into a germline BRCA-mutant (gBRCAm) cohort and a non-gBRCAm cohort. Within each cohort, the patients were randomly assigned 2:1 to receive maintenance therapy with niraparib (300 mg daily) or placebo. Maintenance was continued until progression, toxicity, or patient withdrawal.
In the gBRCAm cohort, 138 patients were assigned to niraparib, and 65 were assigned to placebo. In the non-gBRCAm cohort, 234 patients were assigned to niraparib, and 116 were assigned to placebo.
Prior results showed a significant improvement in progression-free survival with niraparib, regardless of gBRCAm status, at a median follow-up of 16.9 months.2 The median follow-up for the current analysis was more than 75 months across groups.1
In the gBRCAm cohort, the median OS was 40.9 months with niraparib and 38.1 months with placebo (hazard ratio [HR], 0.85; 95% CI, 0.61-1.20). In the non-gBRCAm cohort, median OS was 31.0 months with niraparib and 34.8 months with placebo (HR, 1.06; 95% CI, 0.81-1.37).
There were numeric, but not significant, improvements in secondary endpoints among niraparib recipients in both the gBRCAm and non-gBRCAm cohorts. These endpoints included the chemotherapy-free interval, time to second progression or death, time to first subsequent therapy, and time to second subsequent therapy.
Dr Matulonis said the niraparib safety profile was consistent with prior reports, and no new safety signals were detected.
Myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) were observed in 3.8% of patients who received niraparib and in 1.7% of those given placebo. The highest incidence of MDS/AML was seen in patients from the gBRCAm cohort who received niraparib (7.4%).
Disclosures: This research was supported by GSK. Dr Matulonis declared affiliations with Agenus, Advaxis, Alkermes, AstraZeneca, Blueprint Medicines, Boehringer Ingelheim, GSK, Merck, NextCure, Novartis, Symphogen, and Trillium.
1. Matulonis UA, Herrstedt J, Oza A, et al. Final overall survival and long-term safety in the ENGOT-OV16/NOVA phase III trial of niraparib in patients with recurrent ovarian cancer. SGO 2023. March 25-28, 2023.
2. Mirza MR, Monk BJ, Herrstedt J, et al. ENGOT-OV16/NOVA Investigators. Niraparib maintenance therapy in platinum-sensitive, recurrent ovarian cancer. N Engl J Med. 2016;375(22):2154-2164. doi:10.1056/NEJMoa1611310