A Trial of HRS-1358 Tablets in Metastatic or Local Advanced Breast Cancer

This study is testing a new oral endocrine therapy drug called HRS-1358 in women with locally advanced or metastatic breast cancer whose tumors are hormone receptor-positive (respond to estrogen). It is for patients who have already received at least one prior hormone therapy in the advanced setting. **You may be eligible if...** - You are a woman with confirmed advanced or metastatic breast cancer - Your cancer is hormone receptor-positive - You are postmenopausal, or if premenopausal/perimenopausal, you are receiving ovarian suppression - You have received at least one prior hormone therapy for advanced disease - Your general health and organ function are adequate (ECOG 0–1) **You may NOT be eligible if...** - Your cancer is not considered suitable for hormone-based treatment - You have uncontrolled or active brain metastases with clinical symptoms - You have a history of significant heart or stroke disease - You have an active autoimmune disease or immune deficiency (including HIV) - You have had a prior organ transplant - You have had prior treatment with a similar drug to HRS-1358 Talk to your doctor to see if this trial is right for you.