This study is a multicenter, open-label, randomized controlled Phase 3 clinical trial. It is planned to enroll 240 female patients with locally advanced or metastatic breast cancer followed by disease progression after previous endocrine therapy.

Inclusion Criteria:

1. Women aged 18 to 75 years old (including both values).
2. ECOG Physical Strength Status (PS) : 0 to 1 point.
3. Patients with locally advanced or metastatic breast cancer confirmed by histology.
4. Patients previously received 1-2 lines of endocrine therapy.
5. Expected survival > 6 months.
6. The functional level of the organs must meet the requirements.
7. Subjects that voluntarily participate in this clinical trial, be willing and able to abide by the procedures related to clinical visits and research, understand the research procedures and have signed the informed consent.

Exclusion Criteria:

1. Patients with rapid disease progress and investigators determine that endocrine therapy is not suitable or tolerant.
2. A history of severe clinical cardiovascular diseases.
3. Patients with uncontrollable tumor-related pain as judged by investigators.
4. Severe infection exists within 4 weeks before the first study administration.
5. Patients with clinically significant endometrial abnormalities.
6. Untreated active hepatitis.
7. Patients known to be allergic to HRS-8080 components.
8. Pregnant and lactating women, or those planning to become pregnant during the study period.