This is a single-center, single-arm clinical study to evaluate the efficacy and safety of iparomlimab and tovorilimab (QL1706) combined with paclitaxel, carboplatin, and bevacizumab as neoadjuvant therapy for advanced ovarian cancer.

Inclusion Criteria:

• Female, aged 18-75 years.
• Histologically confirmed high-grade serous ovarian cancer, fallopian tube cancer, or primary peritoneal adenocarcinoma.
• FIGO stage III-IV unresectable ovarian cancer.
• Life expectancy ≥16 weeks.
• No prior anti-tumor therapy, including radiotherapy, chemotherapy, targeted therapy, or immunotherapy.
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
• Adequate organ function, with laboratory test results meeting the following requirements:Hemoglobin (Hb) ≥90 g/L; Absolute neutrophil count (ANC) ≥1.5×10⁹/L; Platelet count (PLT) ≥100×10⁹/L; Total bilirubin (TBIL) ≤1.5× upper limit of normal (ULN); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5×ULN (or ≤5×ULN in patients with liver metastases); Serum creatinine clearance (CrCl) >50 mL/min (calculated using the Cockcroft-Gault formula); Coagulation function: international normalized ratio (INR) ≤1.5×ULN and activated partial thromboplastin time (APTT) ≤1.5×ULN.
• The subject agrees to use effective contraceptive measures from the signing of the informed consent form until 120 days after the last dose of the study drug. Female subjects of childbearing potential (15-49 years) must have a negative urine pregnancy test within 7 days before the start of treatment and must not be lactating. A female patient is considered to be of childbearing potential if she has menstruated, has not reached a postmenopausal state (defined as ≥12 consecutive months of amenorrhea for reasons other than menopause), and has not undergone sterilization surgery (e.g., hysterectomy, bilateral tubal ligation, or bilateral oophorectomy).
• No contraindications for surgery.
• The subject voluntarily participates in this study, signs the informed consent form, is compliant with the protocol, and cooperates with follow-up.

Exclusion Criteria:

• Non-epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer (e.g., germ cell tumors), as well as ovarian tumors of low malignant potential (e.g., borderline ovarian tumors).
• Prior immunotherapy, including immune checkpoint inhibitory antibodies (e.g., anti-PD-1, anti-PD-L1, anti-CTLA-4 antibodies, etc.), immune checkpoint agonistic antibodies (e.g., anti-ICOS, anti-CD40, anti-CD137, anti-GITR, anti-OX40 antibodies, etc.), and immune cell therapy.
• Known hypersensitivity to large molecule protein preparations. Contraindications or allergy to any component of iparomlimab and tovorilimab (QL1706), paclitaxel, or carboplatin.
• Major surgery (excluding diagnostic laparoscopy; local surgical treatment of isolated lesions is acceptable) within 28 days before the first dose.
• History of allogeneic tissue/solid organ transplantation.
• Presence of a condition requiring systemic corticosteroids (>10 mg prednisone equivalent per day) or other immunosuppressive agents (e.g., cyclophosphamide, azathioprine, methotrexate, thalidomide, TNF-α inhibitors, etc.) within 2 weeks before the first dose. Topical corticosteroids, nasal sprays, and inhaled steroids are permitted. Systemic corticosteroids for the prevention of contrast media allergy are allowed.
• Active or potentially recurrent autoimmune disease, with the following exceptions: vitiligo, alopecia, psoriasis, or eczema not requiring systemic treatment; hypothyroidism due to autoimmune thyroiditis requiring only stable hormone replacement therapy; type I diabetes mellitus requiring only stable insulin replacement therapy.
• Other active malignancies within the past 5 years, except for locally curable cancers that have been cured (e.g., basal or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the cervix or breast), and breast cancer that has not recurred for >3 years after radical surgery.
• History of interstitial lung disease and/or pneumonitis, or pulmonary hypertension.
• Symptomatic, untreated, or clinically unstable brain metastases or leptomeningeal metastases.
• Hypertension (systolic blood pressure >150 mmHg and/or diastolic blood pressure >100 mmHg) or diabetes that remains poorly controlled despite standard treatment; uncontrolled or symptomatic arrhythmia.
• Thromboembolic events (e.g., cerebrovascular accident, including transient ischemic attack, cerebral hemorrhage, cerebral infarction, or pulmonary embolism) within 6 months before the start of study treatment.
• Myocardial infarction, severe/unstable angina pectoris, or symptomatic congestive heart failure (New York Heart Association [NYHA] class III or IV) within the past 12 months.
• HIV-positive patients; HBsAg-positive with HBV DNA ≥2000 IU/mL or ≥10⁴ copies/mL; HCV antibody-positive with detectable HCV RNA.
• Participation in another clinical trial within the previous 60 days or during the study treatment period.
• Any other condition that, in the investigator's judgment, may interfere with the conduct of the study or the interpretation of the results. Other circumstances deemed by the investigator to make the patient unsuitable for enrollment.