SNF Platform Study of HR+/ HER2-advanced Breast Cancer

Inclusion Criteria:

1. Female aged ≥18 years;

2. HR+/HER2- invasive breast cancer confirmed by histology (specific definition: ER >10% positive tumor cells by immunohistochemistry is defined as ER positive, PR >10%positive tumor cells is defined as PR positive, ER and/or PR positive is defined asHR positive; HER2 0-1+ or HER2 + but negative by FISH without amplification wasdefined as HER2 negative);

3. Locally advanced breast cancer (unable to undergo radical local treatment) orrecurrent metastatic breast cancer;

4. HR+/HER2- advanced breast cancer patients who had previously received CDK4/6inhibitor therapy;

5. At least one measurable lesion according to RECIST 1.1 (conventional CT scan ≥20 mm,spiral CT scan ≥10 mm, measurable lesion has not received radiotherapy);

6. The functions of the main organs are basically normal and meet the followingconditions: I. Blood routine examination criteria shall meet: HB ≥90 g/L (no blood transfusionwithin 14 days); The ANC acuity 1.5 x 109 / L; PLT acuity 75 x 109 / L; Ii.Biochemical tests should meet the following criteria: TBIL ≤1.5×ULN (upper limit ofnormal value); ALT and AST ≤3×ULN; If liver metastases were present, ALT and AST≤ 5×ULN; Serum Cr ≤1×ULN, endogenous creatinine clearance > 50 ml/min (Cockcroft-Gaultformula);

7. They have not received radiotherapy, molecular targeted therapy, or surgery within 3weeks before the start of the study, and have recovered from the acute toxicity ofprevious treatment (if surgery was performed, the wound has healed completely); Noperipheral neuropathy or grade I peripheral neurotoxicity;

8. ECOG score ≤2, and life expectancy ≥3 months;

9. Fertile female subjects were required to use a medically approved contraceptivemethod during the study treatment period and for at least 3 months after the lastuse of the study drug;

10. Subjects volunteered to join the study, signed informed consent, had goodcompliance, and cooperated with follow-up.

Exclusion Criteria:

1. Radiotherapy (except for palliative causes), chemotherapy, and immunotherapy wereused in the first 3 weeks of treatment, except bisphosphonate (which can be used forbone metastasis);

2. Uncontrolled central nervous system metastases (indicating symptomatic orsymptomatic treatment with glucocorticoids or mannitol);

3. A history of clinically important or uncontrolled heart disease, includingcongestive heart failure, angina pectoris, myocardial infarction, or ventriculararrhythmia within the last 6 months;

4. Persistent grade 1 or higher adverse reactions caused by previous treatments. Theexception to this is hair loss or something the researchers don't think should beruled out. Such cases should be clearly documented in the investigator's notes;

5. Underwent major surgery (except minor outpatient procedures, such as placement ofvascular access) within 3 weeks of the first course of trial treatment;

6. Pregnant or lactating patients; Malignancy (except basal cell carcinoma of the skin,which has been cured, and carcinoma in situ of the cervix) in the past 5 years.