Clinical Trial Evaluating the Efficacy and Safety of ZL-2306 (Niraparib) in Ovarian Cancer Patient

Inclusion Criteria: * Aged 18 years or older female. * High-grade serous or dominantly high-grade serous ovarian cancer * The subject shall have received two lines of platinum-containing chemotherapy, complete response \[CR\] or partial response \[PR\] after first-line platinum-containing chemotherapy, and after received at least 4 cycles of platinum-containing (must be carboplatin or cisplatin or nedaplatin) in second-line platinum-containing chemotherapy. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 Exclusion Criteria: * Patients who have undergone ascites drainage with the last two cycles of the last chemotherapy regimen prior to enrollment. * Symptomatic brain metastases or leptomeningeal metastases that have not been controlled. * Patients who have been diagnosed previously or currently with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML).