A Study of TQB2102 for Injection in Patients With Recurrent/Metastatic Breast Cancer

Inclusion Criteria: * Subjects voluntarily participate in this study and sign informed consent; * Between the ages of 18-75 years (subject to the date of signing the informed consent); Eastern cooperative oncology group (ECOG) score 0-1; estimated survival time ≥3 months; * Breast cancer patients diagnosed with HER2 expression by pathological examination, with evidence of local focal recurrence or distant metastasis, are not suitable for surgery or radiotherapy for cure; * Disease progression or intolerance during or after the most recent treatment period must be present before participating in clinical trials; * At least one measurable lesion (based on Response Evaluation Criteria In Solid Tumors 1.1); * The main organs function are normally; * Female participants of childbearing age should agree to use contraception during the study period and for 6 months after the end of the study; Have a negative serum pregnancy test within 7 days prior to study enrollment and must be a non-lactating subject; Male participants should agree that contraception must be used during the study period and for 6 months after the end of the study period. Exclusion Criteria: * Concomitant disease and medical history: 1. Has diagnosed and/or treated additional malignancy within 3 years prior to first administration of study drug; 2. Adverse effects due to any prior treatment have not been restored according to CommonTerminology Criteria for Adverse Events (CTCAE) 5.0 ≤ level 1 (Excluding hair loss); 3. Major surgical treatment, incision biopsy, or significant traumatic injury received within 28 days prior to study treatment; 4. Long-term unhealed wounds or fractures; 5. Patients who have a prior history of interstitial lung disease/pneumonia requiring steroid intervention, or who are present with interstitial lung disease/pneumonia, or who are suspected of having interstitial lung disease/pneumonia on screening imaging and cannot be ruled out; 6. Arterial/venous thrombosis events, such as cerebrovascular accident, deep vein thrombosis, and pulmonary embolism, occurred within 6 months before the first medication; 7. Patients who have a history of psychotropic substance abuse and are unable to abstain or have mental disorders; 8. Patients with any severe and/or uncontrolled disease; * Tumor related symptoms and treatment: 1. Patients who have been treated with other antitumor drug, such as chemotherapy, radical radiotherapy, or immunotherapy, within 4 weeks prior to the first dose, or who are still within 5 half-lives of the drug; 2. Received Chinese patent drugs with anti-tumor indications specified in the National Medical Products Administration (NMPA) approved drug instructions within 2 week before the study treatment; 3. Patients whose imaging shows that the tumor has invaded important blood vessels or who are determined by the investigators to be highly likely to invade important blood vessels during follow-up studies and cause fatal major bleeding; 4. Uncontrolled pleural effusion, ascites, and moderate or higher pericardial effusion requiring repeated drainage; 5. Known presence of cancerous meningitis or clinically active central nervous system metastasis; Patients who have been stable for at least 4 weeks after treatment and have been off corticosteroids for at least 2 weeks are excluded; 6. Patients with severe bone injury due to tumor bone metastasis; * Study treatment related: people who are known to be allergic to the study drug or its excipients, or to humanized monoclonal antibody products; * Patients who participated in and used other anti-tumor clinical trials within 4 weeks before the first medication; * In the judgment of the investigator, there is a situation that seriously endangers the safety of the subjects or affects the completion of the study.