AZD9833 China PK Study

Inclusion Criteria:

1. Any menopausal status:

2. Pre-menopausal women must have commenced treatment with an LHRH agonist atleast 4 weeks prior to the start of study intervention and must be willing tocontinue to receive LHRH agonist therapy for the duration of the study.

3. Post-menopausal defined according to standard criteria in the protocol.

4. Histological or cytological confirmation of adenocarcinoma of the breast.

5. Documented positive ER status and HER2 negative status of primary or metastatictumour tissue.

6. ECOG performance status 0 to 1.

7. Metastatic disease and radiological or objective evidence of progression on or afterthe last systemic therapy prior to the start of study intervention.

8. At least one lesion as per RECIST Version 1.1 that can be accurately assessed atbaseline and is suitable for repeated assessment by CT, MRI, or plain X-ray orclinical examination.

9. Recurrence or progression on at least one line of endocrine therapy in themetastatic disease setting.

10. For Part A and Part B cohort 1, patients should be eligible for SERD monotherapytreatment.

11. For Part B Cohort 2, patients should be eligible for SERD treatment and CDK4/6inhibitors, and prior treatment with CDK4/6 inhibitors is not permitted.

12. For Part B Cohort 3, patients should be eligible for SERD treatment and mTORinhibitors, and prior treatment with mTOR inhibitors is not permitted.

Exclusion Criteria:

1. Previous treatment with AZD9833.

2. Presence of life-threatening metastatic visceral disease, uncontrolled CNSmetastatic disease or life-threatening extensive hepatic involvement.

3. Any evidence of severe or uncontrolled systemic diseases, including uncontrolledhypertension and active bleeding diatheses, or infection requiring intravenousantibiotic therapy, which makes it undesirable for the patient to participate in thestudy or which would jeopardize compliance with the protocol.

4. Inadequate bone marrow reserve or organ function.

5. Any clinically important and symptomatic heart disease.

6. Any concurrent anti-cancer treatment.

7. Refractory nausea and vomiting, uncontrolled chronic gastrointestinal diseases,inability to swallow the formulated product, or previous significant bowel resectionthat would preclude adequate absorption of AZD9833 (and palbociclib and everolimus).

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.