Exploratory Study of Advanced Breast Cancer in HER2 Positive Patients With Failure of Multi-line Therapy Treated by Combination of Inetetamab (Cipterbin) + PD-1 Inhibitor Combined With Utidelone.

1. Age: 18-75 years old female patients;
2. The results showed that HER-2 was positive at least once in patients with recurrent and metastatic breast cancer confirmed by pathology: HER-2 (+ + +) was confirmed by immunohistochemistry; if HER-2 (+ +), fish / CISH was required to confirm HER-2 amplification;
3. Previous treatment (including neoadjuvant, adjuvant and rescue therapy) received at least trastuzumab and TKIs;
4. It is allowed that the previous rescue chemotherapy does not exceed 3 lines, and must be disease progression before being included in the study; it is allowed to receive rescue endocrine therapy; chemotherapy allows to receive one of the chemotherapy of albumin binding paclitaxel, vinorelbine, gemcitabine, capecitabine and aribrin;
5. At least one target lesion can be defined according to RECIST 1.1, and the target lesion has not received radiotherapy (or other local treatment), unless it progresses after the treatment;
6. Before the study, chemotherapy and targeted therapy must be completed for at least 2 weeks, and endocrine therapy and antiangiogenic drug treatment for 1 week;
7. ECoG PS: 0-1 points;
8. The expected survival time was more than 3 months;
9. The function of the main organs is normal, that is to say, it meets the following standards:

1）Blood routine examination standard should meet (no blood transfusion and blood products within 14 days, not used G-CSF and other hematopoietic stimulating factors were corrected)

• Hb≥90g/L；

  ②ANC≥1.5×109/L；

  ③PLT≥75×109/L； 2）Biochemical examination should meet the following standards:

• TBIL\<1.5×ULN；

  • Alt, AST \< 2.5 × ULN, liver metastasis \< 5 × ULN;

    • Bun and Cr ≤ 1 × ULN or creatinine clearance rate ≥ 50ml / min (Cockcroft Gault formula).

      10.Women of childbearing age must have a pregnancy test (serum) within 7 days before enrollment, and the results are negative, and they are willing to use appropriate contraceptive methods during the trial and within 8 weeks after the last administration of the trial drug; 11.The subjects volunteered to join the study, signed the informed consent form, had good compliance and cooperated with the follow-up.

Exclusion Criteria:

1. Symptomatic, uncontrolled brain metastases or leptomeningeal metastases.However, patients with stable condition after local treatment for 4 weeks could be enrolled;
2. There was effusion in the third space which could not be controlled by drainage or air pressure;
3. Interstitial lung disease, non-infectious pneumonia, memory pneumonia, pulmonary fibrosis and other diseases;
4. Those who have a history of live attenuated vaccine vaccination in the 28 days before the first study medication or are expected to receive live attenuated vaccine in the study;
5. Other malignant tumors in the past 3 years, excluding cervical carcinoma in situ, basal cell carcinoma of skin or squamous cell carcinoma of skin;
6. Patients with hypertension who could not be reduced to normal range after antihypertensive drug treatment (systolic blood pressure > 140 mmHg, diastolic blood pressure > 90 mmHg);
7. Suffering from serious or uncontrollable diseases, including but not limited to:

1) Active viral infection, such as HIV, HBV active phase (HBsAg positive and HBV-DNA ≥ 103, hepatitis C antibody positive); 2) Previous severe cardiovascular diseases: uncontrollable hypertension; myocardial infarction, unstable arrhythmia, congestive heart failure, pericarditis, myocarditis, etc. in the first six and six patients; according to NYHA standard, grade III \~ IV cardiac insufficiency, or left ventricular ejection fraction (LVEF) \< 50% according to NYHA standard; 8.Patients with a history of psychotropic substance abuse and unable to quit or with mental disorders; 9.According to the judgment of the researchers, there are other patients with accompanying diseases that seriously endanger the safety of patients or affect patients to complete the study; 10.Pregnant or lactating women; 11.The researchers think it is not suitable for the participants.