A Study of Niraparib Combined With Bevacizumab Maintenance Treatment in Participants With Advanced Ovarian Cancer Following Response on Front-Line Platinum-Based Chemotherapy

Niraparib will be administered orally once a day continuously throughout each 21 day cycle (84-day cycle after amendment 2). The starting dose of niraparib will be based on the participant's Baseline actual body weight or platelet count. Participants with a Baseline actual body weight of greater than equal to (\>=) 77 kg and Baseline platelet count of \>=150,000/ microliter (μL) will take 300 mg/day (3X100mg) at each dose administration. Participants with a Baseline actual body weight of less than (\<) 77 kg and/or Baseline platelet count of \<150,000/μL will take 200 mg (2X100 mg) at each dose administration.

Maintenance bevacizumab 15 mg/kg will be administered via a 30-minute IV infusion on Day 1 of every 21-day cycle in the absence of progressive disease (PD), unacceptable toxicity, participant withdrawal, Investigator's decision, or death. Bevacizumab will be administered for up to 10 months during the maintenance phase or up to a total of 15 months inclusive of approximately 5 months of bevacizumab received with chemotherapy.