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

This study is testing a combination of three drugs — sirolimus (albumin-bound), palbociclib, and fulvestrant — for women with hormone receptor-positive (HR+), HER2-negative advanced breast cancer. All three drugs target different pathways involved in cancer cell growth. **You may be eligible if...** - You are a woman aged 18 or older who is post-menopausal - You have HR-positive, HER2-negative advanced or metastatic breast cancer confirmed by biopsy - Your doctor believes you are suitable for palbociclib and fulvestrant treatment - Your general health score (ECOG) is 0–1 - You have at least one measurable tumor on imaging (for the dose-expansion stage) **You may NOT be eligible if...** - You were previously diagnosed with HER2-positive breast cancer - Your cancer is in a life-threatening crisis (e.g., large uncontrolled fluid buildup, extensive lung or liver involvement) - You have previously received fulvestrant or drugs targeting the PI3K/AKT/mTOR pathway Talk to your doctor to see if this trial is right for you.