To Evaluate a Phase Ia/Ib Clinical Study of EG017 in Patients With Advanced Breast Cancer.

To evaluate the safety, tolerability, pharmacokinetics and efficacy of EG017 in androgen receptor-positive, estrogen receptor-positive, and human epidermal growth factor receptor-2-negative patients with advanced breast cancer.

Inclusion Criteria:Female, 18-75 years old (stage Ia only) or 18-80 years old (stage Ib only);Expected survival ≥ 12 weeks (stage Ia only) or ≥ 24 weeks (stage Ib only);Subjects with ECOG score of physical state 0~1;Histologically confirmed recurrent or metastatic advanced breast cancer;Exclusion Criteria:Those who have had a severe allergic reaction to any drug or its components in this study in the past;Present with primary central nervous system (CNS) malignancies; Subjects with CNS metastasis who have failed local treatment (except asymptomatic BMS, or symptomatic BMS with complete remission of symptoms ≥ 2 weeks after treatment for BMS);Has any disease or syndrome that requires or is likely to require systemic steroid therapy during the study period;Gastrointestinal disorders or gastrointestinal diseases will significantly affect the absorption of test drugs (such as ulcerative disease, uncontrolled vomiting, diarrhea, malabsorption syndrome, biliary drainage status, etc.), or subjects cannot take drugs orally: