Inclusion Criteria:
1. Female participants aged ≥18 years and ≤75 years at enrollment;
2. Histologically or cytologically confirmed diagnosis of epithelial ovarian cancer, fallopian tube carcinoma, or primary peritoneal carcinoma, with histopathological confirmation of high-grade serous carcinoma or endometrioid carcinoma, and FIGO stage (2014 edition) III-IV;
3. Meeting the neoadjuvant indications for ovarian cancer (preoperative evaluation by a gynecologic oncologist indicates low likelihood of achieving R0 resection with initial debulking surgery, or the patient's physical condition is unsuitable for immediate surgery due to poor tolerance to PDS);
4. Positive HRD testing result;
5. Presence of at least one measurable lesion meeting RECIST 1.1 criteria;
6. Expected survival time ≥12 weeks;
7. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1;
8. Absence of severe hematologic, cardiac, pulmonary, hepatic, renal dysfunction, or immunodeficiency disorders. Within one week prior to the first administration, the functional status of vital organs must meet the following requirements (supportive therapies such as any blood components or cell growth factors are prohibited within 14 days before the first dose):
1. Complete blood count: HGB ≥ 90 g/L; WBC ≥ 4.0 × 10⁹/L; NEUT ≥ 2.0 × 10⁹/L; PLT ≥ 100 × 10⁹/L;
2. Blood biochemistry: TBIL ≤ 1.5 × ULN; ALT and AST ≤ 3 × ULN; BUN and Cr ≤ 1.5 × ULN with creatinine clearance ≥ 50 mL/min;
3. Coagulation function: INR ≤ 1.5 × ULN; APTT ≤ 1.5 × ULN;
4. Within 4 weeks prior to the first dose, cardiac ultrasound must demonstrate: left ventricular ejection fraction (LVEF)\> 50%;
9. Pregnancy test results must be negative in patients of childbearing age, with voluntary use of effective and reliable contraceptive measures during the study;
10. Participants must voluntarily enroll in the study, sign an informed consent form, demonstrate good compliance, and agree to participate in follow-up visits.
Exclusion Criteria:
1. Ovarian cancer, fallopian tube cancer, primary peritoneal cancer (e.g., germ cell tumors), or ovarian tumors with low malignant potential (e.g., borderline tumors) of non-epithelial origin;
2. Previous receipt of antitumor therapy, including but not limited to radiotherapy, chemotherapy, surgery, targeted therapy, and immunotherapy (Note: lymph node dissection or biopsy performed for clinical staging purposes using tissue obtained via puncture biopsy or laparoscopic exploration is permitted);
3. History of other malignancies within the past 5 years, excluding cured localized tumors (e.g., basal cell carcinoma of skin, squamous cell carcinoma of skin, superficial bladder cancer, cervical carcinoma in situ, breast carcinoma in situ);
4. Participation in other drug clinical trials and use of investigational drugs within 4 weeks prior to enrollment;
5. Administration of live attenuated vaccines within 4 weeks before initial dosing or planned during the study period;
6. Known history of allergy to any component of this regimen;
7. Subjects with active infectious diseases;
8. Subjects with any severe and/or uncontrolled diseases;
9. Active autoimmune diseases requiring systemic treatment within 2 years prior to study initiation, or autoimmune diseases at risk of recurrence; exceptions include: non-systemically treatable dermatoses (e.g., vitiligo, alopecia, psoriasis, or eczema); hypothyroidism due to autoimmune thyroiditis requiring only stable hormone replacement therapy; well-controlled type 1 diabetes mellitus; and conditions deemed by investigators unlikely to recur without external triggers;
10. Pregnant or breastfeeding women, or women of childbearing potential with positive baseline pregnancy test results.
11. According to the investigator's assessment, the patient has a severe comorbid condition that poses significant risks to safety or impedes participation in the study, including but not limited to: severe hypertension uncontrolled by medication (systolic blood pressure ≥150 mmHg, diastolic blood pressure ≥100 mmHg), myocardial ischemia or myocardial infarction, severe arrhythmias, congestive heart failure grade ≥2, severe pulmonary dysfunction/disease, severe diabetes mellitus, or active infections;
12. A documented history of neurological or psychiatric disorders, including epilepsy or dementia;
13. Known history of allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation;
14. Known history of interstitial lung disease or non-infectious pneumonia;
15. Diagnosis of immunodeficiency or ongoing systemic glucocorticoid therapy or any other form of immunosuppressive treatment;
16. Presence of any condition increasing bleeding risk, such as severe hemorrhoids, acute gastritis, or gastric and duodenal ulcers;
17. History of dysphagia or any gastrointestinal disorder affecting drug absorption;
18. Any other circumstances deemed inappropriate for study participation by the investigator.
