• Adult females (19 years old and older) with CA125-associated recurrent epithelial adenocarcinoma of ovarian, fallopian tube or peritoneal origin.

• Have one of the eligible histologic epithelial cell types: serous adenocarcinoma, endometrioid adenocarcinoma, undifferentiated carcinoma, clear cell adenocarcinoma, mixed epithelial carcinoma, carcinosarcoma, transitional cell carcinoma, malignant Brenner's Tumor, or adenocarcinoma not otherwise specified (N.O.S.).

• Patients must have had a complete or partial response to front-line platinum-based therapy (at least three cycles) and a treatment -free interval without clinical evidence of progressive disease at least 6 months.

• No known deleterious or pathogenic germline or somatic BRreast CAncer gene (BRCA) mutation

• Must have had an elevated serum CA125 \> 2 times of UNL measured at the first diagnosis or screening within 28 days of start of study treatment.

• Must have measurable disease, including identification of marker lesions, by radiographic or physical criteria suitable for evaluation according to RECIST v1.1 for documentation of disease response or progression.

• Must have a ECOG Performance Status of 0, 1 or 2

• Must have adequate organ function defined as:

‣ neutrophil count ≥1000 μL

⁃ platelet count ≥100,000 μL

⁃ Hemoglobin \>9.0 g/dl

⁃ Serum creatinine \<1.5 times the upper normal limits (UNL) or creatinine clearance \> 45 mL/min/1.73 m2

⁃ bilirubin \<1.5 times the UNL

⁃ SGOT and SGPT \< 2 times the UL

• Must have voluntarily agreed to participate and have signed the informed consent, and are willing to complete all study procedures.