Phase I Study of the HS-10352 in Patients With Advanced Breast Cancer

Inclusion Criteria:

1. Men or women aged more than or equal to (≥) 18 years, and less than (\<) 75 years.
2. HR+ HER2- locally advanced or metastatic breast cancer patients confirmed by histology or cytology for who that standard treatment is invalid, unavailable or intolerable.
3. Patients have at least one target lesion according to RECEST 1.1. The requirements for target lesions are: measurable lesions without local treatment such as irradiation, or with definite progress after local treatment, with the longest diameter ≥ 10 mm in the baseline period (in case of lymph nodes, the shortest axis ≥ 15 mm is required)
4. ECOG performance status was 0-1 and did not deteriorate in the previous 2 weeks.
5. Estimated life expectancy greater than (\>) three months.
6. Females should be using adequate contraceptive measures throughout the study; should not be breastfeeding at the time of screening, during the study and until 3 months after completion of the study; and must have evidence of non-childbearing potential.
7. Sign Informed Consent Form.

Exclusion Criteria:

1. Treatment with any of the following:

   1. Previous or current treatment with PI3K, AKT or mTOR inhibitors.
   2. Any cytotoxic chemotherapy, investigational agents within 21 days of the first dose of study drug; anticancer drugs which have been received within 14 days before the first administration.
   3. Radiotherapy with a limited field of radiation for palliation within 2 weeks of the first dose of study drug, or patients received more than 30% of the bone marrow irradiation, or large-scale radiotherapy within 4 weeks of the first dose.
   4. Major surgery (including craniotomy, thoracotomy, or laparotomy, etc.) within 4 weeks of the first dose of study drug.
2. Inadequate bone marrow reserve or organ function.
3. Uncontrolled pleural effusion or ascites or pericardial effusion.
4. Known and untreated, or active central nervous system metastases.
5. History of primary or secondary diabetes.
6. History of acute or chronic pancreatitis
7. Refractory nausea, vomiting, or chronic gastrointestinal diseases, or inability to swallow the study drug that would preclude adequate absorption of HS-10352.
8. History of hypersensitivity to any active or inactive ingredient of HS-10352 or to drugs with a similar chemical structure or class to HS-10352.
9. Judgment by the investigator that the patient should not participate in the study if the patient is unlikely to comply with study procedures, restrictions, and requirements.
10. Any disease or condition that, in the opinion of the investigator, would compromise the safety of the patient or interfere with study assessments.