The Efficacy and Safety of Dalpiciclib Plus Endocrine Therapy in HR-positive / HER2-negative Advanced Breast Cancer Patients With Visceral Crisis

Inclusion Criteria

• •1. Postmenopausal or premenopausal/perimenopausal women aged ≥18 meet one of the following:
• •A) Previous bilateral oophorectomy, or age ≥60 years; or B) age\<60. Natural postmenopausal status (defined as spontaneous cessation of regular menstruation for at least 12 consecutive months without other pathological or physiological causes), E2 and FSH at postmenopausal levels; or C) premenopausal/perimenopausal women must receive LHRH agonists therapy during the study.
• •2. Female breast cancer patients diagnosed as HR-positive or HER2-negative by pathological examination are not suitable for surgical resection or radiotherapy for the purpose of cure.
• •A) ER-positive and/or PR-positive are defined as: ≥ 1% of all tumor cells are positively stained (confirmed by investigator review at the site); B) HER2-negative are defined as: 0/1 + by standard immunohistochemistry (IHC); HER2/CEP17 ratio less than 2.0 by ISH or HER2 gene copy number less than 4 (confirmed by investigator review at the site).
• •3. Any clinical signs or symptoms of symptomatic brain metastasis or visceral metastasis (at least one of the following: carcinomatous meningitis or leptomeningeal metastasis; pleural effusion; ascites; abdominal pain caused by liver or peritoneal metastasis; dyspnea caused by pleural effusion or pulmonary lymphangitis; elevated liver enzymes (\> 2 × ULN); rapid elevation of bilirubin \> 1.5 × ULN in the absence of Gilbert's syndrome or biliary obstruction; pathologically confirmed bone marrow metastasis; hemoglobin less than 10 g) and patients who cannot tolerate chemotherapy or are considered by the investigator to be inappropriate for chemotherapy or chemotherapy.
• •4. Adequate bone marrow function. Definitions are as follows: a) neutrophil count (ANC) ≥ 1,500/mm3 (1.5 x 109L) (14 without growth factors); b) platelet count (PLT) ≥ 100,000/mm3 (100 x 109L) (7 without correction); c) hemoglobin (Hb) ≥ 8 g/dL (80 g/L) (7 without correction).
• •5. Female subjects who are not postmenopausal or surgically sterile must have a serum pregnancy test within 7 days before the first dose and have a negative result, and are willing to abstain from sexual intercourse or use a medically recognized highly effective contraceptive measure after signing the informed consent, during the study, and for 1 year after administration of the study drug.
• •6. Voluntarily participate in this study, sign informed consent, have good compliance and are willing to cooperate with follow-up.