Neoadjuvant Ivonescimab Plus Chemotherapy Followed by Concurrent Chemoradiotherapy in High-Risk Locally Advanced Cervical Cancer

Inclusion Criteria: * Able to understand and voluntarily sign the written informed consent form before any study-specific procedures. * Female participants aged ≥18 years on the day of signing informed consent. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * Expected survival time ≥3 months. * Histologically confirmed diagnosis of cervical cancer. * Histological types limited to squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma. * No prior anti-tumor treatments (including but not limited to radiotherapy, chemotherapy, surgery, targeted therapy, and immunotherapy). Note: Lymph node dissection or biopsy for clinical staging is allowed. * FIGO 2018 stage III-IVA cervical cancer unsuitable for curative surgery. Lymph node metastasis may be confirmed by biopsy or imaging. Imaging-based lymph node metastasis must meet: MRI/CT showing positive lymph node with short-axis diameter ≥10 mm, and ≥15 mm to be used as target lesion. * At least one measurable lesion per RECIST v1.1 criteria. * PD-L1 CPS score ≥1 in tumor tissue. * Must provide tumor tissue sample before treatment (FFPE blocks or ≥5 unstained slides, preferably freshly obtained). * Adequate organ function as per screening labs: * Hematological (without transfusion or growth factors within 2 weeks): * ANC ≥1.5×10⁹/L * Platelets ≥90×10⁹/L * Hemoglobin ≥9.0 g/dL * Renal: * Creatinine ≤1.5×ULN or CrCl ≥50 mL/min (≥60 mL/min if cisplatin is planned), calculated by Cockcroft-Gault: CrCl (mL/min) = \[(140 - age) × weight (kg) × 0.85\] / \[serum creatinine (mg/dL) × 72\] * Hepatic: * Total bilirubin ≤1.5×ULN (≤3×ULN if Gilbert's syndrome suspected) * AST and ALT ≤2.5×ULN * Coagulation: * INR ≤1.5×ULN and APTT ≤1.5×ULN (unless on anticoagulants with stable dosing) * Women of childbearing potential must have a negative serum pregnancy test within 7 days prior to first dose, and agree to use effective contraception during treatment and for at least 120 days after last dose of study drug and 180 days after chemoradiotherapy. * Effective contraception includes hormonal contraception, IUDs, or double barrier methods. Periodic abstinence and rhythm methods are not acceptable. Exclusion Criteria: * Cervical cancer of non-eligible histology (e.g., neuroendocrine carcinoma, sarcoma). * Evidence of distant metastasis, including inguinal lymph node metastasis or lymph node involvement above L1 vertebral level. * History of total hysterectomy (removal of uterus and cervix). Subtotal hysterectomy or cornuostomy preserving the cervix is acceptable. * Anatomical or geometric contraindications to brachytherapy. * Active malignancies within 2 years, except for treated non-melanoma skin cancer, superficial bladder cancer, in-situ breast cancer (note: cervical carcinoma in situ history is exclusionary). * Bilateral hydronephrosis deemed non-relievable by nephrostomy or ureteral stenting. * Anti-tumor therapy within 2 weeks before treatment initiation (including but not limited to radiotherapy, chemotherapy, surgery, targeted therapy, immunotherapy, or immuno-co-stimulatory agents like ICOS, CD40, CD137, GITR, OX40 antibodies). * Immunomodulatory drugs (e.g., thymosin, interferon, IL-2) within 2 weeks before treatment. * Systemic corticosteroids (\>10 mg/day prednisone or equivalent) or other immunosuppressants within 2 weeks, except: * Inhaled, ophthalmic, or topical steroids ≤10 mg/day prednisone or equivalent * Physiologic hormone replacement ≤10 mg/day prednisone or equivalent * Prophylactic corticosteroids for hypersensitivity (e.g., CT contrast) * Active infections requiring systemic treatment (e.g., active TB, syphilis, systemic fungal infections), except HBV antiviral therapy. * Severe infection within 4 weeks prior to treatment (e.g., hospitalization, sepsis, severe pneumonia). * Major surgery or significant trauma (e.g., fractures) within 4 weeks, or planned elective major surgery. Pelvic/para-aortic lymph node dissection not exclusionary. * Live vaccines within 4 weeks. * Active or history of autoimmune diseases except for: * Vitiligo, alopecia, psoriasis, or eczema not requiring systemic therapy * Autoimmune thyroiditis requiring only stable hormone therapy * Type I diabetes requiring only stable insulin replacement * Any of the following cardiovascular/cerebrovascular diseases: * MI, unstable angina, PE, aortic dissection, DVT, or arterial embolism within 6 months * NYHA Class II or greater heart failure * Significant arrhythmias needing long-term treatment (stable asymptomatic Afib allowed) * Stroke (CVA) within 6 months * LVEF \<50% * History of myocarditis or cardiomyopathy * Known primary or secondary immunodeficiency, including HIV antibody positivity. * Active HBV infection: HBsAg positive with HBV DNA \>1000 IU/mL or \>5000 copies/mL; active HCV infection. * Exception: treated and stable HBV patients with HBV DNA ≤500 IU/mL (or ≤2500 copies/mL); cured HCV patients (HCVAb+ but HCV RNA-) allowed. * History of or active inflammatory bowel disease (Crohn's, ulcerative colitis), diverticulitis. * Known history of allogeneic organ or stem cell transplantation. * Interstitial lung disease or history of non-infectious pneumonitis. * History of severe hypersensitivity to monoclonal antibodies. * Known contraindications to cisplatin/carboplatin or paclitaxel. * Pregnant or breastfeeding women. * Any condition that may interfere with the study drug's safety or efficacy evaluation as judged by the investigator (e.g., other serious illness, psychiatric disorders).