TQB2930 Injection for the Treatment of HER2-positive Advanced Breast Cancer

Inclusion Criteria: * Subjects voluntarily participate in this study and sign the informed consent form; * Age: 18-75 years (at time of signing Informed Consent Form (ICF); Eastern Cooperative Oncology Group (ECOG) performance status ≤1; estimated life expectancy \>3 months; * Cytologically or histologically confirmed Human Epidermal Growth Factor Receptor 2 (HER2)-positive recurrent or metastatic breast cancer; * Received ≥2 prior lines of anti-HER2 targeted therapy in the advanced setting; * At least one measurable lesion meeting Response Evaluation Criteria in Solid Tumors, Version 1.1 (RECIST 1.1) criteria (excluding brain lesions); * Willing to receive one of the investigator-selected chemotherapy regimens; * Adequate organ function; * Female subjects of childbearing potential must agree to use effective contraception (e.g., Intrauterine Device (IUD), oral contraceptives, or condoms) during the study and for 6 months after study completion. Exclusion Criteria: * Concurrent Diseases and Medical History: * Other malignancies within 5 years before randomization or concurrent malignancies (except adequately treated non-melanoma skin cancer, in situ cervical cancer, or other cancers with curative treatment and no recurrence for ≥3 years); * Uncontrolled toxicities (\>CTCAE Grade 1) from prior therapies (excluding alopecia); * Major surgery, open biopsy, or significant traumatic injury within 28 days before randomization; * Non-healing wounds or fractures; * Arterial/venous thromboembolic events within 6 months before randomization; * History of drug abuse or psychiatric disorders that may affect compliance; * Poorly controlled hypertension (e.g., Systolic Blood Pressure (SBP) \>160 mmHg despite treatment); * ≥Grade 2 myocardial ischemia/infarction, arrhythmias, or congestive heart failure (New York Heart Association （NYHA）Class ≥II); * Active or uncontrolled severe infections (≥CTCAE Grade 2); * Known chronic hepatitis B; * Active syphilis infection; * Renal failure requiring hemodialysis/peritoneal dialysis; * Immunodeficiency disorders (e.g., Human Immunodeficiency Virus (HIV) ; * Poorly controlled diabetes; * Urine protein ≥++ on dipstick with 24-hour urine protein \>1.0 g; * Epilepsy requiring medication. * Tumor-Related Conditions and Treatments: * Chemotherapy, radiotherapy, or immunotherapy within 4 weeks before randomization (or within 5 half-lives of prior drugs, whichever is shorter); * Chinese herbal medicines with approved antitumor indications (per National Medical Products Administration (NMPA) labeling) within 2 weeks; * Severe Bone Lesions from bone metastases; * Untreated brain metastases, Leptomeningeal metastases, or carcinomatous meningitis; * Prior HER2-targeted therapy-induced Left Ventricular Ejection Fraction (LVEF) decline to \<50% or absolute reduction \>15%; * Uncontrolled or symptomatic Hypertension requiring ongoing bisphosphonates; * Uncontrolled cancer-related pain; * Existed Lymphangitis Carcinomatosa or uncontrolled effusions; * Use of Immunosuppressant or systemic corticosteroids (≥10 mg/day prednisone equivalent) within 2 weeks. * Severe hypersensitivity to monoclonal antibodies; * Participation in other antitumor clinical trials with investigational drugs within 4 weeks before randomization; * Any condition deemed by the investigator to jeopardize subject safety or study completion.