Clinical Study of HRS-8080 in Combination With Dalpiciclib Isethionate Tablets in Patients With Unresectable or Metastatic Breast Cancer

Inclusion Criteria:

1. Women aged 18-75 years with both ends included.

2. ECOG Physical status 0-1 points.

3. Patients with histologically confirmed metastatic or locally advanced breast cancer.

4. Dose-exploration stage: advanced stage has received at least 1 line of endocrinetherapy progression in the past, efficacy extension stage: has not received anysystemic treatment for advanced disease5.

5. Antitumor therapy with radiographically confirmed disease progression or receivingadvanced first-line standard endocrine therapy with no clinical or radiographicallyconfirmed disease progression.

6. At least one measurable extracranial lesion must be present.

7. Expected survival >3 months.

8. The functional level of the organ must meet the requirements of the test.

9. Fertile female subjects must consent to use highly effective contraception duringthe study treatment period and for 7 months after the end of the study treatmentperiod; Fertile female subjects must be negative for serum HCG within 7 days priorto study enrollment and must be non-lactating.

10. Volunteer to participate in this clinical trial, be willing and able to followclinical visit and study related procedures, understand study procedures and havesigned informed consent.

Exclusion Criteria:

1. Symptoms of visceral metastasis.

2. Previous treatment did not meet trial requirements.

3. Received nitrosourea or mitomycin within 6 weeks before the first dose in thisstudy; Received major organ surgery, cytotoxic drugs, immunotherapy, targetedtherapy, anti-tumor traditional Chinese medicine or other clinical investigationaldrugs within 4 weeks before the first medication; He received endocrine therapy andpalliative radiotherapy within 2 weeks before the first dose.

4. Less than 14 days after the first dose of CYP3A4; CYP3A4 is treated with a stronginducer <28 days from the date of first administration.

5. Patients with active (untreated or clinically symptomatic) brain metastases,cancerous meningitis, spinal cord compression, or a history of primary tumors of thecentral nervous system.

6. A history of clinically severe cardiovascular disease.

7. Patients with uncontrolled tumor-related pain as judged by the investigator.

8. Those who received immunosuppressive agents or systemic hormone therapy forimmunosuppression within 2 weeks prior to the first dose.

9. The damage caused by the subject receiving other treatments has been recovered.

10. Severe infection occurred within 4 weeks prior to the second dose.

11. The first study investigated the occurrence of arteriovenous thrombosis within 6months prior to medication.

12. Patients with clinically significant endometrial abnormalities.

13. Untreated active hepatitis.

14. Subjects had other malignancies within the past 5 years or currently.

15. Have an inherited or acquired bleeding tendency.

16. History of active autoimmune disease, immune deficiency, and autoimmune disease.

17. One of the many factors that affect oral medications.

18. Subjects are acutely infected or have active TB and require medication.

19. Known allergy to HRS-8080 ingredient, Dalpiciclib and ingredient.

20. Pregnant and lactating women or women planning to become pregnant during the studyperiod.

21. There is a clear history of neurological or psychiatric disorders and the subjectshave a history of psychotropic substance abuse or drug use.

22. The presence of other serious physical or mental illnesses or abnormalities inlaboratory tests that may increase the risk of participating in the study orinterfere with the study results, as well as patients deemed unsuitable forparticipation in this study by the investigator.