For a study, researchers sought to evaluate the efficacy and safety of niraparib plus bevacizumab as a first-line maintenance treatment for patients with newly diagnosed advanced ovarian cancer. Patients with stage IIIB or IV ovarian, fallopian tube, or primary peritoneal cancer were eligible to enroll in this multicenter, phase II, single-arm, open-label trial (NCT03326193). Patients needed a complete response, partial response, or no indication of illness after the first platinum-based chemotherapy with more than equal cycles of bevacizumab before they were eligible for debulking surgery. PFS at 18 months was the key measure of success. The primary aim was overall survival, although the secondary endpoints were progression-free survival, safety, and overall survival. At 18 months, the PFS rate was 62% (95% CI 52-71%) among all 105 evaluable patients, 76% (95% CI 61-87) among those who were homologous recombination deficient (HRd), 47% (95% CI 31-64%) among those who were HR proficient (HRp), and 56% (95% CI 31-79%) among those whose HR not determined (HRnd) (December 24, 2020, cutoff). After a median follow-up of 28.7 months (IQR, 23.9-32.5 months), the median progression-free survival (PFS) for the entire population (N=105) was 19.6 months (95% CI 16.5-25.1), and it was 28.3 months (95% CI 19.9-NE), 14.2 months (95% CI 8.6-16.8), and 12.1 months (95% CI 8.0-NE) in the HRd, HRp, and HRnd subgroups, respectively (June 16, 2021, cutoff). Thrombocytopenia (74/105), fatigue (60/105), and anemia (55/105; December 24, 2020, cutoff) were the most prevalent treatment-related side events (due to niraparib and/or bevacizumab). Promising progression-free survival data were seen with niraparib + bevacizumab as first-line maintenance treatment. Both niraparib and bevacizumab were safe to use, with side effects similar to those seen with each drug used alone.