Breast Cancer Clinical Trials

• Female aged ≥18 years;

• 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 as HR positive; HER2 0-1+ or HER2 + but negative by FISH without amplification was defined as HER2 negative);

• Locally advanced breast cancer (unable to undergo radical local treatment) or recurrent metastatic breast cancer;

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

• 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);

• The functions of the main organs are basically normal and meet the following conditions:

• I. Blood routine examination criteria shall meet: HB ≥90 g/L (no blood transfusion within 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 of normal 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-Gault formula);

• They have not received radiotherapy, molecular targeted therapy, or surgery within 3 weeks before the start of the study, and have recovered from the acute toxicity of previous treatment (if surgery was performed, the wound has healed completely); No peripheral neuropathy or grade I peripheral neurotoxicity;

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

• Fertile female subjects were required to use a medically approved contraceptive method during the study treatment period and for at least 3 months after the last use of the study drug;

⁃ Subjects volunteered to join the study, signed informed consent, had good compliance, and cooperated with follow-up.