A Phase Ⅲ Study of Hemay022 in Combination With AI In Advanced Breast Cancer

Inclusion Criteria

• •1. Age ≥18 years old；
• •2. Subjects must give informed consent to the study before the study entry and voluntarily sign a written informed consent form;
• •3. Breast cancer subjects diagnosed by pathology（histology or cytology）;
• •4. ER positive and HER2 over-expression (immunohistochemical IHC test 3+ and/or in situ hybridization ISH test positive)；Previous test results are acceptable.
• •5. Advanced/metastatic breast cancer that has previously received treatment failure with trastuzumab (or trastuzumab biosimilar) regimen;Or (new) adjuvant therapy during treatment with trastuzumab (or trastuzumab biosimilar) or within 12 months after the end of treatment, disease recurrence or progression；Patients with first-line systemic treatment for relapse (previously received trastuzumab or trastuzumab biosimilars)；Or patients who are not suitable for trastuzumab treatment；Patients who have failed previous anti-HER2-ADC drug therapy can also be included.
• •6. At least one lesion (measurable and/or non-measurable) that can be evaluated by CT/MRI and meets the reproducible evaluation requirements of RECIST V1.1;
• •7. ECOG Performance Status of 0-1;
• •8. The estimated survival time is more than 3 months;
• •9. Postmenopausal women
• •Postmenopausal is defined as meeting any one of the following four conditions:
• •Past bilateral oophorectomy; Age ≥60 years old; Age \<60 years old, natural menopause ≥12 months, in the past 1 year without chemotherapy, tamoxifen, toremifene or ovarian castration, the level of follicle stimulating hormone (FSH) and estradiol Within the postmenopausal range (use the reference range of the local laboratory).
• •Patients younger than 60 years old who are taking tamoxifen or toremifene, their FSH and estradiol levels are within the postmenopausal range (use the reference range of the local laboratory); Premenopausal or perimenopausal women who do not meet the above-mentioned menopausal criteria can also be included in this study, but they must also receive ovarian suppression therapy that meets the standards of medical or surgical castration treatment. Drug ovarian suppression therapy has been started at least 21 days before the start of this program, and Must be continued during the treatment plan;
• •10. Adequate bone marrow, liver, kidney, and coagulation Bone Marrow Function (No blood transfusion or adjuvant leukocyte or platelet augmentation drugs were used within 1 week before screening) Absolute value of neutrophils (ANC) ≥1.5×109/L Hemoglobin (HB) ≥90g/L (transfusion allowed) Platelet (PLT) ≥80×109/L Liver function Liver function grade Child-Pugh A/B (≤9 points) Alanine transferase (ALT) or aspartate aminotransferase (AST) ≤2.5 ULN in the absence of liver metastasis; ALT or AST≤ 5x ULN with liver metastasis Renal function: serum creatinine ≤1.5 times ULN;
• •11. All previous treatment-related toxicities must be CTCAE (version 5.0) ≤ Grade 2 at the time of randomization, except for hair loss, pigmentation, and long-term toxicity caused by radiotherapy (which cannot be recovered by the investigator's judgment)；
• •12. Women patients of childbearing age (including their partners) have no pregnancy plan and voluntarily take effective contraceptive measures from the signing of the informed consent form to 3 months after the last medication.