A randomized, double-blind, multicenter phase III clinical study to evaluate the efficacy and safety of sirolimus for injection (albumin-bound) combined with fulvestrant in patients with HR+ and HER2- advanced breast cancer.
1. Aged 18 or above, regardless of gender; female patients must be postmenopausal, or premenopausal/perimenopausal.
2. Pathologically confirmed HR+, HER2- breast cancer.
3. Locally advanced or metastatic breast cancer, not suitable for curative surgery or radiotherapy, and no current clinical indication for chemotherapy.
4. Previously received at least one, up to two lines of systemic therapy (including at least one line of endocrine therapy combined with CDK4/6 inhibitor therapy).
1. Previous pathological diagnosis of HER2-positive breast cancer.
2. Patients judged by the investigator to be unsuitable for endocrine therapy.
3. Patients who have previously received PI3K/AKT/mTOR inhibitors, fulvestrant, or other ER-targeted therapies (including oral SERDs, ER protein degraders PROTAC, etc.).
4. Received chemotherapy, radiotherapy, biological therapy, targeted therapy, immunotherapy, or other anti-tumor treatments within 4 weeks before randomization.