• The subjects voluntarily joined the study, signed an informed consent form, and had good compliance.

• Age: 18-75 years old; Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score: 0\

⁃ 1 point; estimated survival time exceeds 3 months.

• Women can be in the late period of menopause and before menopause/innerspring. If they are before menopause/siege period, they must continue to receive ovarian function inhibitory treatment during the research period to enter the group.

• Anthropologically confirmed HR-positive and HER2-negative breast cancer.

• Locally advanced or metastatic diseases that cannot undergo radical surgery.

• Queue 1 Previous treatment requirements: progress after endocrine therapy; Queue 2 Previous treatment requirements: progress after endocrine therapy.

• Have one or more phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA)/v-akt murine thymoma viral oncogene homolog 1 (AKT1)/phosphatase and tensin homolog deleted on chromosome ten (PTEN) gene mutations.

• At least one measurable lesion exists according to the RECIST 1.1 standard.

• Good function of the main organs

• Female subjects of childbearing age should agree that contraceptive measures (such as Buds, contraceptives or condoms) must be used during the study period and within 6 months after the study ends; the serum pregnancy test is negative within 7 days before the study enrollment. , and must be non-lactation subjects; male subjects should agree to adopt contraceptive measures within 6 months after the end of the study period.