The purpose of this study is to estimate the cumulative incidence of all adverse events (AEs), including serious adverse events (SAEs), adverse event of special interest (AESI), among participants who have been administered niraparib as per the approved indications.

This is a long-term prospective, observational post-marketing surveillance study of niraparib in participants with ovarian cancer (including fallopian tube, or primary peritoneal cancer) who are in complete or partial response to first-line platinum-based chemotherapy or who had complete or partial response to 2 or more lines of platinum-based chemotherapy or who have been treated with 3 or more prior chemotherapy regimens with either: BRCA mutation irrespective of platinum sensitivity; or platinum-sensitive HRD positive. The study will assess the safety and effectiveness of niraparib for its approved indication with real-world setting in South Korea.

The study will enroll approximately 600 participants. The data will be collected prospectively at the study sites will be recorded into electronic case report forms (e-CRFs). All the participants will be assigned to a single observational cohort:

• Participants With Ovarian Cancer

The multi-center study will be conducted in South Korea. Data collection will be based on routinely scheduled and emergency visits during a 24-month surveillance period or until end of the study whichever occurs first after drug administration. The overall duration of the study will be approximately 6 years.

Inclusion Criteria:

1. Monotherapy for the maintenance treatment of adult participants with ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to first-line platinum-based chemotherapy.
2. Monotherapy for the maintenance treatment of adult participants with recurrent high-grade serous ovarian cancer (including fallopian tube, or primary peritoneal cancer) who are in a complete or partial response to 2 or more lines of platinum-based chemotherapy.
3. Monotherapy treatment of adult participants with recurrent ovarian, fallopian tube or primary peritoneal cancer who have been treated with three or more prior chemotherapy regimens with either a) BRCA mutation (irrespective of platinum sensitivity) or b) platinum-sensitive HRD positive.

Exclusion Criteria:

1. Treated with niraparib outside of the locally approved label in Korea.
2. Niraparib is contraindicated as per product label.
3. Participating in other clinical trials of cancer treatment.

Participants who have been prescribed niraparib for the first time in a real-world setting as a monotherapy treatment for participants with recurrent ovarian, fallopian tube or primary peritoneal cancer.

Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.

IPD from eligible studies will be shared with qualified researchers according to the criteria and process described on https://vivli.org/ourmember/takeda/. For approved requests, the researchers will be provided access to anonymized data (to respect patient privacy in line with applicable laws and regulations) and with information necessary to address the research objectives under the terms of a data sharing agreement.