Japan Phase 2 Study of Niraparib (Maintenance Therapy) in Participants With Relapsed Ovarian Cancer

The drug being tested in this study is called niraparib. Niraparib is being tested to treat people who have platinum-sensitive, relapsed ovarian cancer, fallopian tube cancer, or primary peritoneal cancer. This study will look at the safety and efficacy of niraparib in Japanese participants. The study will enroll approximately 15 participants. Participants will be enrolled to one group and after that will be asked to take niraparib capsules at the same time each day throughout the study: \- Niraparib 300 mg This multi-center trial will be conducted in Japan. The overall time to participate in this study is approximately 28 months. Participants will make multiple visits to the clinic in the treatment period, and the post-treatment period including follow-up assessments after the last dose of the study drug.