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.