A Study of Sirolimus (Albumin-Bound) in Combination With Palbociclib and Fulvestrant for the Treatment of Advanced Breast Cancer

Exclusion Criteria

• •1\. Previously diagnosed with HER2 - positive breast cancer through pathological examination.
• •2\. Patients deemed by the investigator as unsuitable for endocrine therapy (e.g., those with visceral crisis posing immediate life-threatening risks in the short term, including: uncontrolled massive effusions \[pleural, pericardial, or peritoneal\], pulmonary lymphangitic carcinomatosis, or hepatic involvement \>50%).
• •3\. Patients who have previously received treatment with fulvestrant or inhibitors such as PI3K/AKT/mTOR.
• •4\. Patients with uncontrolled third-space fluid accumulation (e.g., pericardial effusion, pleural effusion, or ascites) requiring repeated drainage or other therapeutic interventions, and deemed ineligible for enrollment by investigators.
• •5\. Patients with a history of severe lung diseases, such as interstitial lung disease and/or pneumonia, or pulmonary hypertension, or radiation pneumonia requiring glucocorticoid treatment.
• •6\. Patients with chronic gastrointestinal dysfunction mainly manifested as diarrhea, such as Crohn's disease, ulcerative colitis, malabsorption, or diarrhea of grade ≥ 1; intestinal obstruction, or other gastrointestinal diseases deemed clinically significant by investigators.
• •7\. Patients with known coagulation disorders such as bleeding tendency; or those who need to use anticoagulants, which may affect the intramuscular injection of fulvestrant or the use of LHRH agonists.
• •8\. Patients with known hypersensitivity or intolerance to any component of the investigational drug(s), their excipients, or LHRH agonists (if applicable).
• •9\. Patients with a history of autoimmune diseases (except tuberous sclerosis), immunodeficiency diseases (including positive HIV test), or other acquired or congenital immunodeficiency diseases, or a history of organ transplantation.