The combination of niraparib (Zejula) and bevacizumab (Avastin) as definitive treatment for recurrent platinum-sensitive ovarian cancer was associated with significant improvements in progression-free survival (PFS), time to first subsequent therapy (TFST), second PFS, and time to second subsequent therapy (TSST) in the patients randomized to the niraparib plus bevacizumab combination compared with niraparib alone, reported Mansoor Raza Mirza, MD, Medical Director, Nordic Society of Gynecological Oncology-Clinical Trial Unit, and Chief Oncologist, Rigshospitalet Copenhagen University Hospital, Denmark, and colleagues at the 2020 American Society of Clinical Oncology Virtual Scientific Program.
Furthermore, the chemotherapy-free regimen was well-tolerated and “no detrimental effect on quality of life was observed,” the investigators wrote in their poster presentation.
A total of 97 patients were randomized to niraparib 300 mg once daily plus bevacizumab 15 mg/kg intravenously every 3 weeks until disease progression (N = 48) or single-agent niraparib (N = 49). Treatment was ongoing in 3 patients in each arm; treatment was discontinued due to disease progression in 39 patients in the monotherapy arm and 32 in the combination arm.
PFS, the primary end point of the study, was 12.5 months in the combination arm versus 5.5 months in the single-agent arm (adjusted hazard ratio [HR], 0.34; P <.0001).
TFST was nearly doubled in the combination arm—14.3 months for niraparib plus bevacizumab versus 7.2 months for niraparib alone (adjusted HR, 0.45; P = .0004).
TSST was 21.8 months in the niraparib plus bevacizumab arm versus 17.3 months in the niraparib-alone arm (adjusted HR, 0.56; P = .014).
Overall survival with 52% event maturity was 29.4 months with the niraparib plus bevacizumab combination compared with 27.8 months with single-agent niraparib (adjusted HR, 0.75; P = .30). The study was not powered to detect a difference in overall survival, nor any of the other efficacy end points, the investigators noted.
The change in mean global health status/quality of life over time as measured by the European Organisation for Research and Treatment of Cancer QLQ-C30 scale was not different between the 2 treatment arms at 10 months postrandomization.
Hypertension and proteinuria were more common in the combination arm compared with the monotherapy arm. The rate of grade 3/4 hypertension was 22.9% versus 0%, respectively.
“These results support the rationale behind a randomized phase 3 trial to change current standard-of-care therapy,” the investigators concluded.