Cipterbin Combined With Vinorelbine in the Treatment of HER2-positive MBC

Inclusion Criteria: * Age ≥18 and ≤70 years old, female. * BMI index in the range of 19.0\~28.0 * ECOG≤1, and the expected os ≥3 months * Unresectable metastatic breast cancer diagnosed by histology or pathology that has received one or more chemotherapy regimens. * HER2 overexpression is +++ by immunohistochemistry (IHC) or + by fluorescence hybridization FISH. * At least one measurable lesion. * Sufficient organ function * Voluntarily signed an informed consent form. * Subjects with good compliance Exclusion Criteria: * Rapid disease progression or threaten important organs and require urgent replacement therapy. * Undergone surgery within 28 days before treatment (except for biopsy) * Received radiotherapy within 21 days before the first study drug treatment or the side effects of radiotherapy have not recovered to 0 or 1 * Suffer from other serious uncontrolled diseases (such as epilepsy, liver failure, kidney failure, etc.) * Suffered from other malignant tumors within 5 years before receiving the first study drug treatment or at the same time. * Severely infected * Clear history of mental illness, or have a history of alcoholism or drug abuse. * Central nervous system metastasis or meningeal metastasis with clinical symptoms * Cardiac function left ventricular ejection fraction \< 50% * Obvious arrhythmia, myocardial ischemia, severe atrioventricular block, cardiac insufficiency, severe heart valve Membrane disease patients * Poorly controlled hypertension * Patients with coagulopathy: INR or APTT ≥1.5×ULN * Allergic to the test drug or its excipients in the study treatment, or have a severe allergic reaction to other monoclonal antibody drugs in the past * Pregnant or breastfeeding, or cannot take reliable contraceptive measures during the trial and within 6 months after the end of the medication Giver * Have received a certain test drug in other interventional clinical trials, the interval is less than 28 days or less than 5 half lives of the drug (whichever is longer) * Have used a monoclonal antibody within 6 months before receiving the first study drug treatment * Have received other drugs that may affect the pharmacokinetic results of the study drug, the interval is less than 28 days or less than 5 half lives of the drug (whichever is longer) * Have received organ transplants (including autologous/allologous stem cell transplants) in the past * Other conditions judged by the investigator to be inappropriate for participating in this trial