Niraparib is a potent and highly selective PARP-1/-2 inhibitor. The primary objective of this trial is to evaluate the pharmacokinetic (PK) properties of ZL-2306 (niraparib) and its metabolite M1 in patients from Mainland China with ovarian cancer, following a single and multiple oral administration of the study drug at the indicated dose (300mg, 200mg or 100mg), once a day.

Inclusion Criteria:

1. Signed informed consent .
2. Female, age ≥ 18 years.
3. Histologically confirmed diagnosis of FIGO stage III or IV ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.
4. Has received no further than second-line platinum-based chemotherapy, and has clinical complete response (CR) or partial response (PR) at least following 4 courses of the last platinum-based chemotherapy.
5. ECOG 0-1.
6. Has good organ function, including:
7. Patient of childbearing potential, has a negative pregnancy test when enrolled and promises to use an adequate method of contraception or abstain from activities that could result in pregnancy from enrolment to the end of study and during the 3 months after the last dose of the study treatment, or be of non-childbearing potential, can be enrolled in the study.
8. Is able to adhere to the protocol.
9. Has recovered from previous chemotherapy induced toxic side effects to ≤ grade 1 CTCAE or basal level, apart from ≤ grade 2 CTCAE peripheral neuropathy or hair loss symptoms at steady state.

Exclusion Criteria:

1. Has a known hypersensitivity to the active or inactive ingredients of ZL-2306 (niraparib) or compound which has similar chemical structure to ZL-2306 (niraparib).
2. Has symptomatic uncontrolled brain or leptomeningeal metastasis.
3. Major surgery or chemotherapy within 3 weeks of starting the study or patient has not recovered from any effects of the surgery.
4. Receive palliative radiotherapy encompassing > 20% of the bone marrow within 1 week of entering the study.
5. Be diagnosed any invasive cancer other than ovarian cancer (apart from cured basal cell carcinoma and squamous cell carcinoma) within 2 years prior to study enrolment.
6. Has a history or current diagnosis of myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML).
7. Has other serious or uncontrolled disease
8. Has any disease, treatment and laboratory abnormality that may interfere the study results and affect the fully attendance of study. Or the patient is considered to be not suitable for the study by the investigator. Cannot receive platelet or red blood cell transfusion within 4 weeks of study drug administration.
9. Pregnant, breastfeeding or expecting to conceive children during the study treatment period.
10. Corrected QT (QTc) interval > 470 msec.
11. Use proton pump inhibitors, antacids or histamine 2 (H2) blockers within 48hrs prior to the first drug administration for PK measurement.